What are antibiotics and how do they work. Which bacterial infections can antibiotics treat. How should antibiotics be taken properly. What are the potential side effects and risks of antibiotic use. What are the main classes of antibiotics and their characteristics.

Understanding Antibiotics: Definition and Mechanism of Action

Antibiotics are powerful medications designed to combat bacterial infections. These drugs work by either killing bacteria directly or inhibiting their ability to reproduce, allowing the body’s natural immune defenses to eliminate the remaining pathogens. It’s crucial to note that antibiotics are ineffective against viral infections and most other types of infections.

How do antibiotics function within the body? Antibiotics target specific structures or processes within bacterial cells that are either absent or different in human cells. This selective targeting allows antibiotics to harm bacteria without causing significant damage to the patient’s own cells.

The Two Main Types of Antibiotic Action

• Bactericidal antibiotics: These drugs kill bacteria directly.
• Bacteriostatic antibiotics: These medications prevent bacteria from reproducing, effectively halting the infection’s spread.

The Importance of Proper Antibiotic Prescription and Use

Healthcare providers strive to prescribe antibiotics for specific bacterial infections whenever possible. However, in some cases, they may initiate treatment with broad-spectrum antibiotics while awaiting the results of tests that identify the specific bacteria causing the infection.

Why is it crucial to take antibiotics as prescribed? Taking antibiotics exactly as directed by your healthcare provider is essential for several reasons:

1. Ensures the infection is fully treated
2. Reduces the risk of antibiotic resistance
3. Minimizes potential side effects
4. Prevents the recurrence of the infection

Patients should always adhere to the prescribed dose, frequency, and duration of antibiotic treatment for optimal effectiveness against specific infections.

The Growing Concern of Antibiotic Resistance

Antibiotic resistance is a significant global health concern. Bacteria can develop resistance to the effects of antibiotics, particularly when these medications are not taken as directed. This phenomenon occurs through various mechanisms, including genetic mutations and the transfer of resistance genes between bacteria.

How does antibiotic resistance develop? When bacteria are exposed to antibiotics, some may survive due to natural variations in their genetic makeup. These surviving bacteria can then reproduce, passing on their resistance to future generations. Over time, this process can lead to the emergence of bacterial strains that are difficult or impossible to treat with existing antibiotics.

Strategies to Combat Antibiotic Resistance

• Proper antibiotic prescribing practices
• Patient education on correct antibiotic use
• Development of new antibiotics
• Improved infection prevention measures
• Enhanced surveillance of antibiotic-resistant bacteria

Common Side Effects and Risks Associated with Antibiotic Use

While antibiotics are generally safe and effective when used appropriately, they can cause various side effects. Some of the most common side effects include:

• Upset stomach
• Diarrhea
• Vaginal yeast infections in women
• Allergic reactions (in some individuals)

Can antibiotics interact with other medications? Yes, antibiotics can interact with various drugs, including oral contraceptives, blood thinners, and certain psychiatric medications. It’s crucial to inform your healthcare provider about all medications you’re taking before starting antibiotic treatment.

Antibiotic-Associated Diarrhea and C. difficile Infections

One of the more serious potential complications of antibiotic use is Clostridioides difficile (C. difficile) infection. This occurs when antibiotics disrupt the normal balance of bacteria in the gut, allowing C. difficile to flourish and cause severe diarrhea.

Major Classes of Antibiotics and Their Characteristics

Antibiotics are grouped into classes based on their chemical structure. However, it’s important to note that antibiotics within each class may affect the body differently and can be effective against different types of bacteria. Here’s an overview of the main antibiotic classes:

Aminoglycosides

Aminoglycosides are potent antibiotics used to treat serious bacterial infections, particularly those caused by gram-negative bacteria. Examples include gentamicin, tobramycin, and amikacin. These antibiotics work by interfering with bacterial protein synthesis.

Carbapenems

Carbapenems are a subclass of beta-lactam antibiotics with a broad spectrum of activity. They are often reserved for treating infections caused by multidrug-resistant bacteria. Examples include meropenem, imipenem, and ertapenem.

Cephalosporins

Cephalosporins are another subclass of beta-lactam antibiotics. They are classified into generations (first through fifth) based on their spectrum of activity and resistance to beta-lactamase enzymes. Examples include cefazolin (first generation), cefuroxime (second generation), and ceftriaxone (third generation).

Fluoroquinolones

Fluoroquinolones are broad-spectrum antibiotics that work by inhibiting bacterial DNA replication. They are effective against both gram-positive and gram-negative bacteria. Examples include ciprofloxacin, levofloxacin, and moxifloxacin.

Glycopeptides and Lipoglycopeptides

These antibiotics are primarily used to treat serious infections caused by gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin is the most well-known glycopeptide antibiotic.

Specialized Antibiotic Classes and Their Applications

Macrolides

Macrolides are a class of antibiotics often used to treat infections in people who are allergic to penicillins. They work by inhibiting bacterial protein synthesis. Examples include erythromycin, azithromycin, and clarithromycin.

Monobactams

Aztreonam is the only antibiotic in the monobactam class. It is unique in that it is effective against gram-negative bacteria but has no activity against gram-positive bacteria. This makes it useful for treating certain infections in patients with penicillin allergies.

Oxazolidinones

Oxazolidinones are a relatively new class of antibiotics used to treat serious infections, often after other antibiotics have been ineffective. Linezolid and tedizolid are examples of this class. They are particularly useful against certain multidrug-resistant gram-positive bacteria.

Penicillins

Penicillins were the first antibiotics discovered and remain an important class of antibiotics today. They work by interfering with bacterial cell wall synthesis. Examples include amoxicillin, ampicillin, and piperacillin.

Polypeptides

Polypeptide antibiotics are used to treat various types of infections. This class includes bacitracin, colistin, and polymyxin B. These antibiotics work by disrupting the bacterial cell membrane.

The Future of Antibiotic Development and Use

As antibiotic resistance continues to pose a significant threat to global health, researchers and healthcare professionals are exploring new strategies to combat this issue. What does the future hold for antibiotic development and use?

• Development of novel antibiotic classes
• Combination therapies to enhance effectiveness
• Bacteriophage therapy as an alternative to traditional antibiotics
• Improved diagnostic tools for faster, more accurate infection identification
• Personalized antibiotic treatments based on genetic factors

How can we contribute to the responsible use of antibiotics? Each individual can play a role in preserving the effectiveness of antibiotics by following these guidelines:

1. Only use antibiotics when prescribed by a healthcare professional
2. Complete the full course of antibiotics as directed
3. Never share antibiotics with others or use leftover antibiotics
4. Practice good hygiene to prevent the spread of infections
5. Stay up-to-date with vaccinations to reduce the need for antibiotics

By understanding the importance of antibiotics, their proper use, and the ongoing efforts to combat antibiotic resistance, we can all contribute to maintaining the effectiveness of these vital medications for future generations.

Overview of Antibiotics – Infections

By

Brian J. Werth

, PharmD, University of Washington School of Pharmacy

Reviewed/Revised Jun 2022 | Modified Sep 2022

VIEW PROFESSIONAL VERSION

Topic Resources

Antibiotics are drugs used to treat bacterial infections Bacterial Infections Bacteria are microscopic, single-celled organisms. They are among the earliest known life forms on earth. There are thousands of different kinds of bacteria, and they live in every conceivable… read more . They are not effective against viral infections and most other infections. Antibiotics either kill bacteria or stop them from reproducing, allowing the body’s natural defenses Defenses Against Infection If the body did not have defenses against infection, it would quickly be overwhelmed by microorganisms. These defenses require a living, properly functioning body. A dead body begins to decay… read more to eliminate them.

• Doctors try to use antibiotics for specific bacterial infections, but they sometimes start antibiotics that can treat many different bacteria while waiting for results of tests that identify the specific bacteria Diagnosis of Infectious Disease Infectious diseases are caused by microorganisms, such as bacteria, viruses, fungi, and parasites. Doctors suspect an infection based on the person’s symptoms, physical examination results,… read more .

• Taking the antibiotics as prescribed is important, and antibiotics should be taken in the dose, frequency, and number of days that are most effective to treat a specific infection.

• Bacteria can develop resistance to the effects of antibiotics, especially if they are not taken as directed.

• Antibiotics can have side effects, such as upset stomach, diarrhea, and, in women, vaginal yeast infections.

• Some people are allergic to certain antibiotics.

Antibiotics are grouped into classes based on their chemical structure. However, antibiotics within each class often affect the body differently and may be effective against different bacteria.

Classes of antibiotics include the following:

• Aminoglycosides Aminoglycosides Aminoglycosides are a class of antibiotics used to treat serious bacterial infections, such as those caused by gram-negative bacteria (especially Pseudomonas aeruginosa). Aminoglycosides… read more

• Carbapenems Carbapenems Carbapenems are a subclass of antibiotics called beta-lactam antibiotics (antibiotics that have a chemical structure called a beta-lactam ring). Beta-lactam antibiotics also include cephalosporins… read more

• Cephalosporins Cephalosporins Cephalosporins are a subclass of antibiotics called beta-lactam antibiotics (antibiotics that have a chemical structure called a beta-lactam ring). Beta-lactam antibiotics also include carbapenems… read more

• Fluoroquinolones Fluoroquinolones Fluoroquinolones are a class of broad-spectrum antibiotics that are used to treat a variety of infections. Fluoroquinolones include the following: Ciprofloxacin Delafloxacin Gemifloxacin read more

• Glycopeptides and lipoglycopeptides Glycopeptides and Lipoglycopeptides Glycopeptides and lipoglycopeptides are antibiotics used to treat complicated and/or serious infections caused by gram-positive bacteria. Glycopeptides and lipoglycopeptides include the following… read more (such as vancomycin)

• Macrolides Macrolides Macrolides are a class of antibiotics that are often used to treat infections in people who are allergic to penicillins. Macrolides include the following: Azithromycin Clarithromycin Erythromycin read more (such as erythromycin and azithromycin)

• Monobactams (aztreonam Aztreonam Aztreonam is the only antibiotic in an antibiotic class called monobactams, which are a subclass of beta-lactam antibiotics (antibiotics that have a chemical structure called a beta-lactam ring). .. read more )

• Oxazolidinones Oxazolidinones: Linezolid and Tedizolid Oxazolidinones are a class of antibiotics used to treat serious infections, often after other antibiotics have been ineffective. Oxazolidinones include the following: Linezolid Tedizolid Oxazolidinones… read more (such as linezolid and tedizolid)

• Penicillins Penicillins Penicillins are a subclass of antibiotics called beta-lactam antibiotics (antibiotics that have a chemical structure called a beta-lactam ring). Carbapenems, cephalosporins, and monobactams… read more

• Polypeptides Polypeptides Polypeptides are a class of antibiotics used to treat several types of infections. Polypeptides include the following: Bacitracin Colistin Polymyxin B Most bacteria have an outer covering (cell… read more

• Rifamycins Rifamycins Rifamycins are antibiotics that work by suppressing the bacteria’s production of genetic material. As a result, the bacteria die. Rifamycins include the following: Rifabutin Rifampin (rifampicin)… read more

• Sulfonamides Sulfonamides Sulfonamides are a class of antibiotics that are effective against many and . Some sulfonamides are applied directly to the skin (topically) to treat burns and skin, vaginal, and eye infections… read more

• Streptogramins (such as quinupristin and dalfopristin Quinupristin and Dalfopristin Quinupristin and dalfopristin belong to a class of antibiotics called streptogramins. These drugs are given together as a combination (quinupristin/dalfopristin). They are used to treat serious… read more )

• Tetracyclines Tetracyclines Tetracyclines are a group of antibiotics used to treat many different bacterial infections. Tetracyclines include the following: Doxycycline Eravacycline Minocycline read more

Carbapenems, cephalosporins, monobactams, and penicillins are subclasses of beta-lactam antibiotics, a class of antibiotic characterized by a chemical structure called a beta-lactam ring.

Other antibiotics that do not fit into the classes listed above include chloramphenicol Chloramphenicol The antibiotic chloramphenicol is used mainly to treat serious infections due to the few bacteria that are resistant to other antibiotics but are still susceptible to chloramphenicol. Its use… read more , clindamycin Clindamycin Clindamycin belongs to a class of antibiotics called lincosamides. Clindamycin is used to treat serious bacterial infections, including some infections that are resistant to other antibiotics… read more , daptomycin Daptomycin The antibiotic daptomycin is used to treat many serious bacterial infections, such as those caused by gram-positive bacteria, including those that are resistant to many other antibiotics. Daptomycin… read more , fosfomycin Fosfomycin Fosfomycin is an antibiotic that has a unique chemical structure. It is used mainly to treat bladder infections caused by Escherichia coli (E. coli) or Enterococcus faecalis. It… read more , lefamulin Lefamulin Lefamulin is an antibiotic that works by interfering with the bacteria’s production of the proteins it needs to grow and multiply. Lefamulin is used to treat community-acquired pneumonia that… read more , metronidazole Metronidazole and Tinidazole Metronidazole is an antibiotic used to treat pelvic, abdominal, soft-tissue, gum, and tooth infections and abscesses in the lungs or brain. It is also the preferred drug for certain protozoal… read more , mupirocin Mupirocin Mupirocin is an antibiotic that is used to treat impetigo and some other bacterial skin infections and to eliminate staphylococci from the nose. Mupirocin works by interfering with the bacteria’s… read more , nitrofurantoin Nitrofurantoin Nitrofurantoin is an antibiotic that is used only to prevent or treat uncomplicated bladder infections. How nitrofurantoin works is not fully understood, but it disrupts several bacterial processes… read more , and tigecycline Tigecycline Tigecycline is the only antibiotic in an antibiotic class called glycylcyclines, which are related to tetracyclines. Tigecycline works by preventing bacteria from producing proteins they need… read more .

Each antibiotic is effective only against certain types of bacteria. In selecting an antibiotic to treat a person with an infection, doctors evaluate which bacteria are likely to be the cause. For example, some infections are caused only by certain types of bacteria. Sometimes one antibiotic is predictably effective against all of the bacteria that are most likely to be causing an infection and so further testing may not be needed.

If infections may be caused by many different types of bacteria or by bacteria that are not predictably susceptible to antibiotics, a laboratory is asked to identify the infecting bacteria Diagnosis of Infectious Disease Infectious diseases are caused by microorganisms, such as bacteria, viruses, fungi, and parasites. Doctors suspect an infection based on the person’s symptoms, physical examination results,… read more from samples of blood, urine, or tissue taken from the person ( see Diagnosis of Infectious Disease Diagnosis of Infectious Disease Infectious diseases are caused by microorganisms, such as bacteria, viruses, fungi, and parasites. Doctors suspect an infection based on the person’s symptoms, physical examination results,… read more ). The infecting bacteria are then tested for susceptibility to a variety of antibiotics. Results of these tests usually take a day or two and thus cannot guide the initial choice of antibiotic if the infection needs to be treated immediately. In such cases, doctors typically start treatment with an antibiotic that is effective against the bacteria most likely to be causing the infection. When test results are back, doctors change the antibiotic if needed.

Antibiotics that are effective in the laboratory do not necessarily work in an infected person. The effectiveness of the treatment depends on

• How well the drug is absorbed into the bloodstream (for drugs taken by mouth Oral route Drugs are introduced into the body by several routes. They may be Taken by mouth (orally) Given by injection into a vein (intravenously, IV), into a muscle (intramuscularly, IM), into the space. .. read more )

• How much of the drug reaches the sites of infection in the body (see Drug Distribution Drug Distribution Drug distribution refers to the movement of a drug to and from the blood and various tissues of the body (for example, fat, muscle, and brain tissue) and the relative proportions of drug in… read more )

• How quickly the body eliminates the drug (see Drug Elimination Drug Elimination Drug elimination is the removal of drugs from the body. (See also Introduction to Administration and Kinetics of Drugs.) All drugs are eventually eliminated from the body. They may be eliminated… read more )

These factors may vary from person to person, depending on other drugs being taken, other disorders present, and the person’s age.

In selecting an antibiotic, doctors also consider the following:

• The nature and seriousness of the infection

• The status of the person’s immune system (how well it can help the drug fight the infection)

• The drug’s possible side effects

• The possibility of allergies or other serious reactions to the drug

• The cost of the drug

Doctors also consider how hard it may be for people to take antibiotics for the entire time prescribed and complete the full course of treatment. People may find it more difficult to complete treatment if the drug must be taken very often or only at specific times (such as before meals, during meals, or after meals).

Combinations of antibiotics may be needed to treat the following:

• Severe infections, particularly during the first days when the bacteria’s susceptibility to antibiotics is not known

• Certain infections caused by bacteria that rapidly develop resistance to a single antibiotic

• Infections caused by more than one type of bacteria if each type is susceptible to a different antibiotic

Bacteria, like all living organisms, change over time in response to environmental challenges. Because of the widespread use and misuse of antibiotics (when antibiotics are not taken as prescribed), bacteria are constantly exposed to these drugs. Although many bacteria die when exposed to antibiotics, if antibiotics are not taken appropriately, some bacteria survive and develop resistance Antibiotic resistance Bacteria are microscopic, single-celled organisms. They are among the earliest known life forms on earth. There are thousands of different kinds of bacteria, and they live in every conceivable… read more to the drugs’ effects. For example, 50 years ago, Staphylococcus aureus (a common cause of skin infections) was very sensitive to penicillin. But over time, strains of this bacteria developed an enzyme able to break down penicillin, making the drug ineffective. Researchers responded by developing a form of penicillin that the enzyme could not break down, but after a few years, the bacteria adapted and became resistant to this modified penicillin. Other bacteria have also developed resistance to antibiotics.

Medical research continues to develop drugs to combat bacteria. But people can help prevent the development of resistance in bacteria by

• Understanding that antibiotics are used to treat bacteria, not viral infections (such as the common cold or the flu), and that doctors do not prescribe antibiotics for these viral infections

• Taking antibiotics exactly as directed, including the correct dose, numbers of times per day, and number of days (it is important to take antibiotics for the full number of days prescribed, even if a person is feeling better)

Did You Know.

..

For severe bacterial infections or for people who cannot keep down food or liquids, antibiotics are usually first given by injection Oral route Drugs are introduced into the body by several routes. They may be Taken by mouth (orally) Given by injection into a vein (intravenously, IV), into a muscle (intramuscularly, IM), into the space… read more (usually into a vein but sometimes into a muscle). When the infection is controlled, antibiotics can then be taken by mouth Oral route Drugs are introduced into the body by several routes. They may be Taken by mouth (orally) Given by injection into a vein (intravenously, IV), into a muscle (intramuscularly, IM), into the space… read more .

For less severe infections, antibiotics can often be taken by mouth from the start.

Antibiotics need to be taken until the infecting bacteria are eliminated from the body, which may be days after the symptoms disappear. Stopping treatment too soon can result in a return of the infection.

A doctor, nurse, or pharmacist can explain how the prescribed antibiotic should be taken and what side effects it may have. Some antibiotics must be taken on an empty stomach. Others should be taken with food. Metronidazole Metronidazole and Tinidazole Metronidazole is an antibiotic used to treat pelvic, abdominal, soft-tissue, gum, and tooth infections and abscesses in the lungs or brain. It is also the preferred drug for certain protozoal… read more , a common antibiotic, causes an unpleasant reaction with alcohol. Also, some antibiotics can interact with other drugs that people may be taking, possibly reducing the effectiveness or increasing the side effects of the antibiotic or the other drugs. Some antibiotics make the skin sensitive to sunlight Chemical photosensitivity Photosensitivity, sometimes referred to as a sun allergy, is an immune system reaction that is triggered by sunlight. Sunlight can trigger immune system reactions. People develop itchy eruptions. .. read more .

Antibiotics are sometimes used to prevent infections (called prophylaxis). For example, prophylactic antibiotics may be given to

• People who have been exposed to a person with meningitis to prevent meningitis from developing

• Some people with abnormal or artificial heart valves before dental and surgical procedures to prevent bacteria from infecting the damaged or artificial valves (such procedures can allow bacteria to enter the body)

• People undergoing surgery that has a high risk of introducing an infection (such as major orthopedic or intestinal surgery)

To avoid the development of antibiotic resistance Antibiotic resistance Bacteria are microscopic, single-celled organisms. They are among the earliest known life forms on earth. There are thousands of different kinds of bacteria, and they live in every conceivable… read more in bacteria and side effects in people, doctors usually give preventive antibiotics for only a short time.

Antibiotics may also be given to people who have a weakened immune system Infections in People With Impaired Defenses Many disorders, drugs, and other treatments can cause a breakdown in the body’s natural defenses. Such a breakdown can lead to infections, which can even be caused by microorganisms that normally… read more , such as people with leukemia, people taking chemotherapy for cancer, or people with AIDS, because such people are particularly susceptible to serious infections. They may need to take the antibiotics for a long time.

Generally, antibiotics are used during pregnancy only when the benefits of treatment outweigh the risks. Some antibiotics are safer than others. Penicillins Penicillins Penicillins are a subclass of antibiotics called beta-lactam antibiotics (antibiotics that have a chemical structure called a beta-lactam ring). Carbapenems, cephalosporins, and monobactams… read more , cephalosporins Cephalosporins Cephalosporins are a subclass of antibiotics called beta-lactam antibiotics (antibiotics that have a chemical structure called a beta-lactam ring). Beta-lactam antibiotics also include carbapenems… read more , and erythromycin Macrolides Macrolides are a class of antibiotics that are often used to treat infections in people who are allergic to penicillins. Macrolides include the following: Azithromycin Clarithromycin Erythromycin read more are among the safest antibiotics to use during pregnancy. Tetracyclines Tetracyclines Tetracyclines are a group of antibiotics used to treat many different bacterial infections. Tetracyclines include the following: Doxycycline Eravacycline Minocycline read more are not used during pregnancy. (See also Drug Use During Pregnancy Drug Use During Pregnancy More than 50% of pregnant women take prescription or nonprescription (over-the-counter) drugs or use social drugs (such as tobacco and alcohol) or illicit drugs at some time during pregnancy… read more .)

Most antibiotics pass into breast milk in large enough amounts to affect a breastfed baby and sometimes cannot be used in women who are breastfeeding. Sometimes a decision to stop breastfeeding or to not use the drug must be made.

If an infection develops during pregnancy or while breastfeeding, women should talk to their doctor about the benefits and risks of treatment. (See also Drug Use During Breastfeeding Drug Use During Breastfeeding When mothers who are breastfeeding have to take a drug, they wonder whether they should stop breastfeeding. The answer depends on the following: How much of the drug passes into the milk Whether… read more .)

Usually, antibiotics taken outside the hospital are given by mouth. However, some infections—such as many of those involving bone (osteomyelitis Osteomyelitis Osteomyelitis is a bone infection usually caused by bacteria, mycobacteria, or fungi. Bacteria, mycobacteria, or fungi can infect bones by spreading through the bloodstream or, more often, by… read more ) or the heart (endocarditis Infective Endocarditis Infective endocarditis is an infection of the lining of the heart (endocardium) and usually also of the heart valves. Infective endocarditis occurs when bacteria enter the bloodstream and travel… read more )—may require antibiotics to be given by vein (intravenously) for a long time, often 4 to 6 weeks. If people have no other conditions that need treatment in the hospital and are feeling relatively well, intravenous (IV) antibiotics may be given at home.

When antibiotics have to be given a long time, the short IV catheters that are inserted into a small vein in the arm or hand (such as those used in most routine hospital procedures) may not be desirable. These catheters last only up to 3 days. Instead, a special type of IV catheter is used. It may be inserted either

• Directly into a large central vein, usually in the neck or chest (called a central catheter)

• Into a small vein in the arm and threaded into a large central vein (called a peripherally inserted central catheter, or a PICC)

Some devices for giving antibiotics IV are simple enough that people and their family members can learn to operate them on their own. In other cases, a visiting nurse must come to the home to give each dose. In either situation, people are carefully supervised to make sure the antibiotic is being given correctly and to watch for possible complications and side effects.

If antibiotics are given at home through an IV catheter, the risk of developing an infection at the site where the catheter is inserted and in the bloodstream is increased. The following may indicate a catheter-related infection:

• Pain, redness, and pus at the catheter insertion site

• Chills and fever (even without problems at the insertion site)

Common side effects of antibiotics include

• Upset stomach

• Diarrhea Gastroenteritis as a Side Effect of Drugs

• In women, vaginal yeast infections Vaginal Yeast Infection (Candidiasis) A vaginal yeast infection (also called candidiasis) is caused by an infectious organism called Candida, usually Candida albicans. A vaginal yeast infection may cause intense itching… read more

Some side effects are more severe and, depending on the antibiotic, may impair the function of the kidneys, liver, bone marrow, or other organs. Blood tests are sometimes done to determine whether these organs have been affected.

Colitis, an inflammation of the large intestine (colon), develops in some people who take antibiotics, especially cephalosporins, clindamycin, fluoroquinolones, or penicillins. This type of colitis, called Clostridioides difficile–induced colitis Clostridioides (formerly Clostridium) difficile–Induced Colitis Clostridioides difficile (C. difficile)–induced colitis is an inflammation of the large intestine (colon) that results in diarrhea. The inflammation is caused by toxin produced… read more , results from toxins produced by the bacteria Clostridioides difficile (C. diff). These bacteria are resistant to many antibiotics and grow in the intestines unchecked when other normal bacteria in the intestine are killed by the antibiotics. Clostridioides difficile–induced colitis can be difficult to treat and can be life threatening, especially in older people.

Antibiotics can also cause allergic reactions Allergies to Drugs People sometimes mistake many adverse drug reactions for allergies. For example, people who experience stomach discomfort after taking aspirin (a common adverse reaction) often say they are… read more . Mild allergic reactions may consist of an itchy rash or slight wheezing. Severe allergic reactions (anaphylaxis Anaphylactic Reactions Anaphylactic reactions are sudden, widespread, potentially severe and life-threatening allergic reactions. Anaphylactic reactions often begin with a feeling of uneasiness, followed by tingling… read more ) can be life threatening and usually include swelling of the throat, inability to breathe, and low blood pressure.

It is important for people to tell health care practitioners if they are allergic to a particular antibiotic and to describe their past reaction when treated with that antibiotic. Many people have side effects when taking an antibiotic, but these effects may not be allergy-related (see Allergies to Drugs Allergies to Drugs People sometimes mistake many adverse drug reactions for allergies. For example, people who experience stomach discomfort after taking aspirin (a common adverse reaction) often say they are… read more ). The distinction is important because people who are allergic to an antibiotic should not be given that drug or an antibiotic closely related to it. That is because allergic reactions may be life threatening. However, people who have experienced only minor side effects can usually take related drugs or even continue taking the same drug. Health care practitioners can determine the significance of any unpleasant reaction people have to an antibiotic.

Generic Name	Select Brand Names
vancomycin	FIRVANQ, Vancocin, Vancocin Powder, VANCOSOL
erythromycin	A/T/S, Akne-mycin, E. E.S., Emcin Clear , EMGEL, E-Mycin, ERYC, Erycette, Eryderm , Erygel, Erymax, EryPed, Ery-Tab, Erythra Derm , Erythrocin, Erythrocin Lactobionate, Erythrocin Stearate, Ilosone, Ilotycin, My-E, PCE, PCE Dispertab , Romycin, Staticin, T-Stat
azithromycin	Azasite, Zithromax, Zithromax Powder, Zithromax Single-Dose , Zithromax Tri-Pak, Zithromax Z-Pak, Zmax, Zmax Pediatric
aztreonam	Azactam, Cayston
linezolid	Zyvox, Zyvox Powder, Zyvox Solution
tedizolid	SIVEXTRO
clindamycin	Cleocin, Cleocin Ovules, Cleocin Pediatric, Cleocin T, CLIN, Clindacin ETZ, Clindacin-P, Clinda-Derm , Clindagel, ClindaMax, ClindaReach, Clindesse, Clindets, Evoclin, PledgaClin, XACIATO
daptomycin	Cubicin, Cubicin RF
fosfomycin	Monurol
lefamulin	Xenleta, Xenleta Solution
metronidazole	Flagyl, Flagyl ER, Flagyl RTU, MetroCream, MetroGel, MetroGel Vaginal, MetroLotion, Noritate, NUVESSA, Nydamax, Rosadan, Rozex, Vandazole, Vitazol
mupirocin	Bactroban, Centany, Centany AT
nitrofurantoin	Furadantin, Macrobid, Macrodantin, Urotoin
tigecycline	Tygacil

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Metronidazole for bacterial infection (Flagyl)

Metronidazole for bacterial infection

Flagyl

In this article

• About metronidazole
• Before taking metronidazole
• How to take metronidazole
• Getting the most from your treatment
• Metronidazole side-effects
• How to store metronidazole
• Important information about all medicines

About metronidazole

Metronidazole is an antibiotic used to treat a wide variety of infections caused by certain types of germ (anaerobic bacteria) and types of micro-organisms called protozoa. These types of organisms often cause infections in areas of the body such as the gums, pelvic cavity and tummy (stomach or intestines) because they do not need oxygen to grow and multiply.

Metronidazole is commonly prescribed to treat an infection called bacterial vaginosis. It is also prescribed before gynaecological surgery and surgery on the intestines, to prevent infection from developing. It can safely be taken by people who are allergic to penicillin.

Metronidazole is also used, alongside other medicines, to get rid of Helicobacter pylori, a bacterial infection often associated with stomach ulcers.

Metronidazole is available as a skin preparation also. This leaflet does not give information about metronidazole when it is used for skin conditions, but there is more information available in a separate leaflet called Metronidazole skin gel and cream.

Before taking metronidazole

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking metronidazole it is important that your doctor or dentist knows:

• If you are pregnant or breastfeeding.
• If you feel you will be unable to stop drinking alcohol for the duration of your treatment.
• If you have any problems with the way your liver works.
• If you have a rare inherited blood disorder called porphyria.
• If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
• If you have ever had an allergic reaction to a medicine.

How to take metronidazole

• Before you start this treatment, read the manufacturer’s printed information leaflet from inside your pack. The manufacturer’s leaflet will give you more information about metronidazole and a full list of metronidazole side-effects which you may experience from taking it.
• Take the tablets or liquid medicine exactly as your doctor or dentist tells you to. The dose you are given will depend upon what type of infection you have, and how severe the infection is.
• As a guide, a typical dose for an adult would be 400 mg two or three times a day, but your dose may be more or less than this. Doses for children depend upon the child’s age and weight. Your doctor will tell you what dose is right for you (or your child), and this will also be printed on the label of the pack to remind you.
• Space your doses evenly throughout the day, and keep taking the medicine until the course is finished, unless you are told to stop by your doctor. Your symptoms may return if you stop taking metronidazole before the end of the course prescribed for you.
• Most courses of metronidazole last for around seven days, but some may be as short as three days and some as long as 14 days. For certain infections you may be given a single, larger dose of metronidazole, usually five 400 mg tablets (2 g) to take at once.
• Take each of your doses with a snack or just after eating a meal. Swallow the tablets whole (that is, without chewing or crushing them) with a full glass of water.
• If you forget to take a dose, take it as soon as you remember and try to space your remaining doses evenly throughout the rest of the day. Do not take two doses together to make up for a forgotten dose.

If you have been given metronidazole suppositories

1. Remove the suppository from its wrapping.
2. Using your finger, gently push the suppository into your back passage (rectum) as far as is comfortable. Many people find that inserting a suppository is easier if they squat or bend forward.
3. Remain still for a few moments to help you to hold the suppository in place.
4. Wash your hands.

Getting the most from your treatment

• Important: do not drink alcohol while you are on metronidazole and for 48 hours after finishing your course of treatment. This is because drinking alcohol with metronidazole is likely to make you feel very sick (nauseated) and cause other unpleasant effects, such as the sensation of having a ‘thumping heart’ (palpitations), hot flushes and headache.
• While you are taking metronidazole your urine may look a darker colour than normal. On its own this is nothing to worry about. However, if you also experience tummy (abdominal) pain, or if you feel sick (nausea) or feel generally unwell, you should let your doctor know.
• If you buy any medicines, check with a pharmacist that they are safe to take with metronidazole. Some cough and cold preparations contain alcohol and should not be taken with metronidazole.
• If you need to take metronidazole for longer than ten days, your doctor may want you to have some tests. Make sure you keep any appointments that your doctor gives to you.

Metronidazole side-effects

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the metronidazole side-effects. You will find a full list in the manufacturer’s information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

How to store metronidazole

• Keep all medicines out of the reach and sight of children.
• Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

• Manufacturer’s PIL, Flagyl® 200 mg and 400 mg Tablets; Sanofi, The electronic Medicines Compendium. Dated December 2021.

• Medicines Complete BNF 85th Edition; British Medical Association and Royal Pharmaceutical Society of Great Britain, London.

New generation antibiotics: pros and cons

Content

• 1 Next generation antibiotics: pros and cons of use
  • 1. 1 New generation antibiotics: effectiveness and risks
    • 1.1.2 Against:
  • 1.2 What are antibiotics?
  • 1.3 How do antibiotics work?
  • 1.4 The problem of antibiotic resistance
  • 1.5 New generation antibiotics
  • 1.6 Benefits of new generation antibiotics
  • 1.7 Disadvantages of new generation antibiotics
  • 1.8 Danger of self-medication with new generation antibiotics
  • 1.9 New generation antibiotics and their effect on the microflora of the body
  • 1.10 Recommendations for the correct use of new generation antibiotics
  • 1.11 Drug natural preparations based on new generation antibiotics
  • 1.12 Q&A:
    • • 1.12.0.1 What are the arguments for using new generation antibiotics?
      • 1.12.0.2 What are the possible negative consequences of using new generation antibiotics?
      • 1.12.0.3 Can new generation antibiotics be dangerous to health?
      • 1.12.0. 4 Are there alternatives to new generation antibiotics?
      • 1.12.0.5 When is the use of new generation antibiotics necessary?
      • 1.12.0.6 Can new generation antibiotics be a universal remedy for all diseases?
  • 1.13 The choice of a new generation antibiotic for the treatment of diseases
  • 1.14 Related videos:

The article discusses the latest antibiotics and their advantages over classical drugs, as well as possible negative consequences and concerns about their effectiveness. Get information about the advantages and disadvantages of using new generation antibiotics before making a treatment decision.

Antibiotics are powerful medicines that can fight many bacterial infections. However, with each passing year, the effectiveness of old antibiotics decreases as bacteria become more and more resistant to them. This forces scientists to constantly work on the creation of new antibiotics that would be more effective and could cope with new types of infections.

New generation antibiotics are drugs that have been created on the basis of new scientific discoveries and technologies. They may be more efficient and faster, but they may also have some drawbacks.

New generation antibiotics can be said to help treat diseases that were previously untreatable.
However, there is another side – the shortcomings of new antibiotics, which can lead to serious consequences.

Both of these opinions have their place and can be argued. The purpose of this article is to look at the pros and cons of new generation antibiotics so that you can make your choice.

New generation antibiotics: efficacy and risks

Pro:

Reducing the risk of antibiotic resistance. Some new generation antibiotics are capable of killing a wider range of bacteria than their predecessors. This may reduce the risk of developing antibiotic resistance, which is an acute medical problem today.

Treatment of severe and complex infections. New generation antibiotics are often used to treat infections caused by several types of bacteria or bacteria that are resistant to other antibiotics. They may also help you recover faster and reduce your risk of complications.

Once a month or more

0%

Half a year

0%

Once a year

100%

Against:

9 0078 High costs. New generation antibiotics typically cost significantly more than their “standard” counterparts. This may limit the access of patients to the necessary treatment, as well as cast doubt on the economic feasibility of their widespread use.

Unsafe. Like any medication, new generation antibiotics have side effects. In addition, some of them may increase the risk of developing a superinfection caused by a different, more antibiotic-resistant bacterium. Therefore, before using a new generation antibiotic, it is necessary to carefully evaluate and compare its potential benefits and possible risks and contraindications.

What are antibiotics?

Antibiotics are medicines designed to fight bacterial infections. They inhibit the vital activity of bacteria and destroy them or stop their reproduction. This allows the body to fight the infection and recover.

Antibiotics are used in the treatment of a wide range of bacterial infections such as pneumonia, tonsillitis, bronchitis, urinary tract infections and others.

Some antibiotics may only be effective against certain types of bacteria, while others are more broadly effective and can fight many types of bacteria.

Antibiotics should only be prescribed by a doctor and in strict accordance with the instructions for use. Misuse of antibiotics can lead to the development of drug resistance and worsening of the patient’s condition.

How do antibiotics work?

Antibiotics are a class of drugs that have been developed to fight bacterial infections. They exert their effect by influencing various processes in the bacterial cell.

One of the most common mechanisms of action of antibiotics is to block the synthesis of the bacterial cell wall or destroy it. This leads to the vulnerability of bacteria and their death. The classic example of an antibiotic that works in this way is penicillin.

Other antibiotics block the synthesis of bacterial proteins or RNA, which also leads to the death of microorganisms. There are a number of antibiotics for this, such as tetracyclines, macrolides, aminoglycosides, etc.

However, not all antibiotics have such a harsh effect on bacteria. So, some antibiotics can fight infection by destroying the membrane of microorganisms, while others stop the growth of bacteria. You can also use antibiotics to change the tone and death of cells, which is the basis of their therapeutic action.

All antibiotics have their own characteristics inside bacterial cells, so it is often necessary to individually select a preparation for a particular case. Despite this, they are one of the most effective means in the fight against bacterial infections.

The problem of antibiotic resistance

The growing problem of antibiotic resistance is becoming increasingly important around the world. Every year there is an increasing number of patients suffering from infections caused by bacteria that do not respond to basic antibiotics. This poses significant health challenges and worsens the prognosis for many patients.

One of the main causes of antibiotic resistance is the misuse and repeated use of antibiotics, both in medical practice and in animal and fish farming. This causes bacteria to develop resistance to antibiotics and become increasingly difficult to treat.

The challenge for science and medicine is to develop new antibiotics that can fight treatment-resistant bacteria. However, this process requires large time and financial costs, as well as high scientific knowledge and technological base.

• Standard antibiotics can no longer fight infections caused by treatment-resistant bacteria.
• The misuse and repeated use of antibiotics is one of the causes of the spread of treatment-resistant bacteria.
• The development of new antibiotics is an important task for science and medicine, which requires a lot of time and resources.

New generation antibiotic varieties

New generation antibiotic development technologies are becoming more diverse every year. Among them, the following varieties can be distinguished:

• Glycopeptides are antibiotics with a powerful bactericidal effect, which manifests itself against bacteria resistant to other classes of antibiotics. They are successfully used to treat acute and chronic infections.
• carbapenems are the most effective antibiotics and are effective against most bacteria, including multi-resistant strains. They are widely used to treat severe infections of the abdominal cavity and purulent-inflammatory diseases.
• Phosphonates are novel antibiotics that are bactericidal against many types of bacteria, including multi-resistant strains. They are effective in treating infections of the skin, respiratory and urinary systems.

It is also worth noting that the varieties of new generation antibiotics can be presented in various forms of release: tablets, capsules, powders for injections, creams and ointments for external use. Each form of release has its advantages and disadvantages and is selected depending on the type of infection and its severity.

Examples of new generation antibiotics Name Form of release Broad spectrum of activity

Benefits of new generation antibiotics

Fast acting – new antibiotics develop their properties much faster than their predecessors. Thanks to this, the treatment of infections has become more effective and faster.

Greater efficacy against microorganisms – new antibiotics are immediately active against most known types of bacteria. This reduces the likelihood of developing resistance and improves treatment outcomes.

Low risk of side effects – the use of new antibiotics does not cause severe side effects, unlike classic ones. Thus, patients can begin recovery without unnecessary pain and complications.

• Let’s list the advantages:
• fast action;
• broad spectrum;
• low risk of side effects.

Ease of use – New generation antibiotics come in a variety of forms – tablets, capsules, injections, nose and eye drops, aerosols. The patient can choose the most suitable form for himself. Also, some of them can be used as a preventive measure.

Disadvantages of new generation antibiotics

One of the main disadvantages of new generation antibiotics is their high cost. This makes drugs out of reach for most citizens, especially in developing countries. In addition, there is often a problem with fakes that may contain less active ingredient or even dangerous additives, which can lead to serious consequences for the health of patients.

Another disadvantage is that the use of new generation antibiotics can lead to the development of resistance in bacteria, making future infections difficult to treat. In addition, some antibiotics can have a negative effect on the intestinal microflora, which can lead to dysbiosis and other health problems.

• High cost ;
• Counterfeit problems ;
• Development of resistance in bacteria ;
• Negative effect on intestinal microflora .

The danger of self-medication with new generation antibiotics

New generation antibiotics are powerful drugs that can effectively fight various infections. However, their use requires special care and supervision by a physician. Unauthorized self-medication with new generation antibiotics can lead to serious consequences.

Doctors warn against self-medication, as this can lead to the development of resistance to the most effective antibiotics. This means that when the infection recurs, treatment becomes much more difficult and takes longer. In addition, the uncontrolled use of new generation antibiotics can adversely affect the microflora of the body, disrupt its balance and cause dysbacteriosis.

The danger of self-treatment with new generation antibiotics is also that the wrong medicine can lead to the development of side effects. This can be a manifestation of allergies, dyspeptic disorders, headaches and other unpleasant symptoms. In addition, some infections can easily masquerade as other diseases, making it necessary to accurately determine the diagnosis and prescribe appropriate treatment.

Bringing all this to light, we can say that self-treatment with new generation antibiotics is not safe. It is best to contact a qualified specialist and get advice on the need and dosage of antibiotics. Only in this case, you can be sure of the effectiveness of the treatment and avoid the undesirable consequences of self-treatment.

New generation antibiotics and their effect on the microflora of the body

New generation antibiotics are drugs developed using new technologies and methods that allow you to fight a wider range of infections. However, they can also have a negative effect on the microflora of the body.

Microflora is a collection of microorganisms that are found in the human body and perform important functions for its health. The use of new generation antibiotics can upset the balance of microflora, which can lead to various health problems.

As a result, many physicians recommend using new generation antibiotics only when the disease cannot be cured by older antibiotics or when the patient’s life is at risk. This minimizes the risk of negative consequences for the microflora of the body.

• Some types of new generation antibiotics can cause dysbacteriosis, which manifests itself in digestive disorders and fungal infections;
• The use of new generation antibiotics can also cause a decrease in immunity, which can lead to various disease states;
• It must be remembered that any antibiotic can have a negative effect on the microflora of the body, so their use should be limited whenever possible.

In summary, next-generation antibiotics are a powerful weapon in the fight against infections, but their use should be considered and taken only when necessary to minimize possible consequences for the body’s microflora.

Recommendations for the correct use of new generation antibiotics

1. Follow the doctor’s instructions and do not exceed the dosage indicated in the prescription. Do not allow self-medication and do not interrupt the course of treatment ahead of schedule without the consent of the doctor.

2. New generation drugs are not a universal remedy for all diseases. Keep in mind that antibiotics kill bacteria, not viruses, so don’t use them to treat colds, flu, or other viral infections.

3. If you experience allergic reactions or other side effects, seek medical attention immediately.

4. Try not to use the same antibiotics for a long time, as this can lead to bacterial resistance and worsen the results of their therapy in the future.

5. Do not use prophylactic antibiotics.

1. Important to remember! To replenish the intestinal microbiota, you need to take probiotics, to increase immunity – immunostimulants. Remember that despite all their achievements, antibiotics can kill not only harmful but also beneficial bacteria in the body.

New generation antibiotic drugs

New generation antibiotics are drugs based on the latest scientific advances in microbiology and pharmacology. They are used to fight bacterial infections and are highly effective in the treatment of a number of diseases.

New generation antibiotics are resistant to a wide range of bacteria and at the same time do not quickly develop resistance to microorganisms. This can significantly reduce the risk of developing antibiotic resistance and ensure a rapid recovery of the patient.

However, the use of new generation antibiotics has its drawbacks. They are more expensive compared to drugs created by earlier methods. In addition, their appointment often requires accurate diagnosis and identification of bacterial species in order to avoid the appointment of ineffective treatment and the development of resistance.

• In summary, the use of new generation antibiotics is an effective way to fight bacterial infections.
• However, their use must be justified and requires more accurate diagnosis and identification of bacterial species.
• At the same time, it is necessary to remember the need to reduce costs and ensure access to medical care for all patients.

Q&A:

What are the arguments for using new generation antibiotics?

New generation antibiotics have a broader spectrum of action and can fight more complex and drug-resistant infections. They can also be used at lower doses and for a shorter course, reducing the risk of side effects and antibiotic resistance.

What are the possible negative consequences of using new generation antibiotics?

New generation antibiotics may be more expensive and out of reach for many people. Also, the use of new antibiotics may lead to the development of new side effects and an increased likelihood of antibiotic resistance.

Can new generation antibiotics be dangerous to health?

Like all medicines, new generation antibiotics can have side effects. However, with proper use and following the instructions of the doctor, the likelihood of negative effects is minimal.

Are there alternatives to new generation antibiotics?

Yes, there are alternatives in the form of older antibiotics, antiseptics, antivirals, antifungals, immunostimulants, and other treatments. However, in each case, the doctor must decide on the choice of the most effective and safe method of treatment.

When is the use of new generation antibiotics necessary?

New generation antibiotics may be needed when the disease is caused by a bacterial infection that is resistant to previous types of antibiotics. Also, the doctor may decide to use new antibiotics in cases where a quick and effective result of treatment is extremely important for the life and health of the patient.

Can new generation antibiotics be a universal remedy for all diseases?

No, new generation antibiotics cannot be a universal remedy for all diseases. They are only effective against bacterial infections and will not work against viruses, fungi and other pathogens.

Choosing a new generation of antibiotics for the treatment of diseases

The wide range of new generation antibiotics on the market can make it difficult to choose the most appropriate drug. However, the right choice can significantly speed up the body’s recovery process and reduce the risk of side effects.

Before choosing an antibiotic, it is necessary to clarify the type of disease, the presence of contraindications and allergic reactions, as well as take into account the age and weight of the patient.

Some antibiotics have a narrower spectrum of activity and may be effective in treating specific conditions, such as urinary or respiratory tract infections. Other drugs have a broader spectrum of action and may be effective in the treatment of complicated infections.

It is also important to follow the rules for taking antibiotics, not to interrupt treatment prematurely and not to exceed the dosage in order to avoid the development of bacterial resistance to the drug.

• In the treatment of urinary tract infection : Narrow spectrum antibiotics such as amoxicillin or cefpodoxime are recommended.
• In the treatment of complicated respiratory tract infections : broader spectrum antibiotics such as levofloxacin or ceftriaxone can be used.
• When treating a skin infection : topical antibiotics such as mupirocin or fusidine ointments or creams are recommended.

Also be aware of possible side effects such as diarrhea, nausea, headache, and interactions of antibiotics with other medications.

Drug Spectrum of action Contraindications

So, the right choice of a new generation antibiotic should be based on taking into account the individual characteristics of the patient, the disease and the spectrum of the drug, as well as the presence of contraindications and possible side effects.

Related videos:

Antibiotics. Sources of antibiotics and history of occurrence. How do antibiotics work? Are they harmful?

Antibiotics are drugs aimed at the destruction of living pathogenic bacteria, they entered our life more than half a century ago and firmly settled in it.

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Thanks to antibiotics, diseases such as tuberculosis, pneumonia, gangrene and many other bacterial infections have ceased to be fatal to humans. But even the most potent antibacterial drugs are not able to cope with all pathogenic bacteria. This is due to the fact that pathogenic bacteria are constantly evolving, developing natural genetic mechanisms to resist drugs. The number of new generations of microbes that are “resistant” to even the strongest antibiotics is growing inexorably every year. Scientists around the world are constantly in search of new effective methods in the fight against invulnerable bacteria.

The history of antibiotics

Even in ancient times in China, India, Egypt and Greece, moldy bread and some types of plants were used to disinfect wounds and abscesses, mentions of the medicinal properties of mold were still in the works of ancient philosophers. In 1873, the scientific work of A.G. Polotebnov “The pathological significance of green mold” about the therapeutic effect of mold on purulent wounds, which he recommended to use in the treatment of skin diseases. But this work has not received due attention in medical circles. Bartomeleo Gozio physician and microbiologist in 189In the 6th year, he isolated mycophenolic acid from mold fungi – the world’s first antibiotic that was active against the bacterium – the causative agent of anthrax. In 1987, French military doctor Ernest Duchene tested molds of the genus Penicillium on guinea pigs and found that the mold had a destructive effect on the typhoid bacillus. Alas, his work also failed to attract attention among the scientific community.

Russian scientist M.G. Tartakovsky in 1904 stated that the substances produced by green mold suppress the development of the causative agent of chicken cholera. American scientists Otis Fisher Black and Carl Alsberg at 19In 13, they obtained a toxic substance from the mold of the genus Penicillium puberulum, which, as it turned out later, was penicillic acid, and had antimicrobial properties. In 1928, the British bacteriologist Alexander Fleming carried out another work aimed at studying the protective reactions of the human body to infectious diseases provoked by staphylococcus bacteria. In the process of conducting an experiment in one of the laboratory bowls, Fleming discovered the formation of colonies of molds that got there in a completely random way. He noticed that there were no staph bacteria around the mold colonies. During this experiment, the scientist concluded that the mold releases a substance that destroys pathogenic bacteria and called it “penicillin”, since it was isolated from fungi of the genus Penicillium notatum, which he reported at a meeting of the Medical Research Club at the University of London on September 13, 1929 years old But even then, Fleming’s work did not arouse much enthusiasm among physicians, since penicillin turned out to be an unstable substance that quickly collapsed even with short-term storage. German scientists Ernst Boris Chain and Australian Howard Flory, who worked in England in the 30s of the twentieth century, came to grips with improving the effectiveness of penicillin. Soon they managed to get a sufficient amount of penicillin in its pure form and test it on laboratory mice. This test showed a very high antibacterial efficacy of the drug. Due to the huge mortality of soldiers from purulent wounds during the Second World War, the need for effective medicines was catastrophically large. At 19In 43, the mass production of penicillin began, thanks to this medicine, hundreds of thousands of human lives were saved all over the world. And only in 1945, Howard Flory, Alexander Fleming and Ernst Boris Chain received the Nobel Prize in Medicine “for the discovery of penicillin and its healing effects in various infectious diseases.” Penicillin was followed by discoveries of other antibacterial agents. In the USSR, the first antibacterial drug was Krustozin, the discovery of which belongs to the microbiologist Zinaida Yermolyeva in 1942 year. Until 2017, scientists around the world made various modifications of the drug, due to the emergence of bacterial resistance to existing drugs. In 2018, scientists at the University of Illinois developed a new class of semi-synthetic antibiotics. This drug was created on the basis of the compound dioxynibomycin and showed its high efficiency against a wide range of gram-negative bacteria. Antibiotic in Greek means “against life”. In 1942, this term was proposed by the American microbiologist Zelman Waksman, whose name is associated with the discovery of another antibacterial agent – streptomycin, which is still used today to treat tuberculosis.

Sources of antibiotics

The main sources of antibiotics are actinomycetes (producing about 80% of natural antibiotics), molds and typical bacteria, but they are far from the only ones. To date, about 30,000 antibiotics of natural origin are known to science, but this does not mean at all that all antibiotics that exist today are produced by living cells. Since the 1960s, chemists have learned to significantly improve the antimicrobial properties of antibiotics produced by natural microorganisms by modifying them by chemical methods. The preparations thus obtained are classified as semi-synthetic antibiotics. Of the variety of antibiotics for medical purposes, only about a hundred are used.

Methods for producing antibiotics

• Biological synthesis (cultivation of producers and isolation of antibiotics by them during their life activity)
• Biosynthesis with chemical modifications (semi-synthetic antibiotics)
• Chemical synthesis (synthetic analogues of natural antibiotics)

900 13

Classification of antibiotics

Depending on the nature of the effect of an antibacterial drug on a pathological cell, antibiotics are divided into two groups: bacteriostatic (pathogenic bacteria remain alive, but lose their ability to reproduce) and bactericidal (bacteria die and are excreted from the body). Classification of antibiotics by chemical structure:

• Beta-lactams (penicillins, cephalosporins, carbapenems, monobactams)
• Glycopeptides (vancomycin, teicoplanin)
• Aminoglycosides (streptomycin, monomycin, kanamycin, neomycin – 1st generation; tamycin, etc. – II generation)
• Tetracyclines
• Macrolides (and azalides)
• Lincosamides
• Levomycetin (chloramphenicol)
• Rifamycins
• Polypeptides
• Polyenes
• Miscellaneous antibiotics (fusidic acid, fusafungine, etc.)

Classification by direction of action:

• Antibacterial antibiotics (the largest group of drugs):
• active against gram-positive microorganisms;
• broad spectrum – act simultaneously on gram-positive and gram-negative bacteria;
• antituberculous, antileprosy, antisyphilitic preparations;
• antifungals
• antitumor antibiotics
• Antiprotozoal and antiviral antibiotics

How do antibiotics work?

The main task of an antibiotic, when it enters the body, is to attach to a bacterium in order to destroy it or deprive it of the opportunity to multiply, as a result of which it will die on its own. To do this, each antibiotic has its own target, as a rule, it is a protein, enzyme or part of the DNA of a pathogenic microorganism, and the mechanism of action on the bacterium. That is why certain antibacterial drugs are prescribed depending on the causative agent of the disease. In medical practice, drugs are used that hit targets accurately without affecting the cells of our body.

Treatment with antibiotics

You cannot prescribe antibiotics on your own, only a doctor can prescribe such a prescription. Antibacterial drugs are used to prevent and treat inflammatory processes caused by pathogenic bacteria. Treatment of viral diseases, for example, SARS, will not be effective.

Antibiotic therapy should not be accompanied by other drugs that can affect their action, and it is also important to observe an equal time interval between antimicrobial doses and in no case combine treatment with alcohol. Do not stop taking antibiotics if you feel relief, the course of treatment prescribed by a qualified specialist must be completed in full.