What is a Z-Pak? Can I use a Z-Pak for sinus infections?

A Z-Pak is an antibiotic commonly prescribed for bacterial infections such as sinus or urinary infections, bronchitis, or tonsillitis

What is a Z-Pak? | Uses | Dosage | Restrictions | Side effects | Alternatives

Sinus pressure? Check. Headache? Check. Enlarged lymph nodes? Check. Z-Pak? Check.

If you have a bacterial infection, your doctor may prescribe you a Z-Pak. A Z-Pak is an antibiotic commonly prescribed for bacterial infections, like sinus infections, bronchitis, or tonsillitis—not viral infections (like the flu, common cold, or COVID-19). Keep reading to learn what a Z-Pak is, the infections it treats, its dosage requirements, side effects, and how it compares to other drugs.

What is a Z-Pak?

A Z-Pak is a five-day course of azithromycin and is used to treat certain bacterial infections by stopping the growth of bacteria in your body. “Z-Pak is the brand-name formulation for a specific antibiotic called azithromycin,” says Amesh Adalja, MD, a board-certified infectious disease physician. “It’s used for a variety of infections including pneumonia, sinus infections, and ear infections, for example.”

This prescription drug is available in generic and is manufactured by many companies, including BOC Sciences, Sun Pharmaceuticals, Sandoz, Alembic, and Pfizer, among other large pharmaceutical companies. Common brands of azithromycin include the Zithromax Z-Pak and the Zithromax TRI-PAK. Azithromycin is also available as an eye drop, called AzaSite. 

Generic azithromycin can cost approximately $37 without insurance, while brand-name Zithromax will cost upwards of $200. However, a SingleCare coupon can reduce that cost to less than $10 for a generic Z-Pak.

What is a Z-Pak used for?

A Z-Pak can treat a variety of bacterial infections in adults and children. Some of the most common infections include: 

• Strep throat
• Sinus infections
• Ear infections
• Skin infections
• Community-acquired pneumonia
• Bronchitis
• Chlamydia
• Cervicitis
• Pharyngitis
• Infected tonsils
• Urethritis 
• Urinary tract infections
• Acute bacterial exacerbations of chronic bronchitis
• Prevention of infections in HIV and AIDS patients

Of these, strep throat is one of the more common diseases treated by a Z-Pak. Because bacteria cause strep throat, a Z-Pak can prevent bacteria from growing, and can decrease the spread of the infection to other people. It can also prevent strep throat from evolving into a more severe illness like rheumatic fever, a condition that can damage your heart valves.

A Z-Pak cannot treat viral infections, like the flu or the common cold. Viral infections cannot be cured by antibiotics. 

How does a Z-pak work?

A Z-pak is in a class of antibiotics referred to as macrolide antibiotics. Macrolides work by killing bacteria or preventing their growth and are considered to be one of the safest antibiotic treatments available. Azithromycin is commonly prescribed as an alternative to penicillin for those needing antibiotics with penicillin allergies. Azithromycin is rated the top prescribed antibiotic in the United States.

Z-pak dosage

There are two main oral forms of azithromycin: liquid (in suspension form) and tablets. The dosage strengths for liquid Zithromax are 100 mg/5 mL and 200 mg/5 mL. The most common dosage strengths for the tablets are 250 mg and 500 mg. There are six tablets in a 250 mg Z-Pak. Azithromycin is also available in higher doses as a powder form, and used for the treatment of sexually transmitted diseases. 

Although the Z-Pak is the most popular form of azithromycin, sometimes doctors prescribe a Zithromax Tri-Pak, which contains three tablets of azithromycin 500 mg, and is taken once daily for 3 days. The Tri-Pak may be prescribed for mild to moderate acute bacterial exacerbations of chronic bronchitis, or for acute bacterial sinusitis. 

If you have strep throat and are allergic to medications like penicillin or amoxicillin, your doctor may prescribe you a Z-Pak of six 250 mg tablets. You take two tablets on the first day, followed by one tablet daily on each of the remaining four days.

It’s important to take this medication as directed by your doctor, usually once a day. The dosage will depend on your diagnosis. For the best results, take this antibiotic at approximately the same time every day and continue to take it until you finish the full prescribed amount, even if you are feeling better. Stopping the medication too early may cause bacteria to grow, and your infection to return.

If you miss a Z-Pak dose, take it as soon as you can. If it’s almost time for your next dose, skip the missed dose—it’s not recommended that you take two doses at once.

Sources: DailyMed, Epocrates

Z-pak restrictions

While Z-Paks can help adults and children recover from bacterial infections, there are some precautions to consider before taking the prescription drug. Tell your doctor if:

• You’re allergic to azithromycin or other antibiotics (this medication may cause allergic reactions in some people)
• You have liver problems, kidney disease, or myasthenia gravis
• You’re taking drugs that may cause QT prolongation, you have heart problems, or you have a family history of sudden cardiac arrest
• You’ve recently received a vaccine or immunization
• You’re taking antacids, as these drugs can interfere with azithromycin 
• You’re pregnant
• You’re breastfeeding (the drug may pass into your breast milk)

Specifically, talk to your healthcare provider about any interactions with current drugs you’re taking. This includes prescription and over-the-counter drugs as well as any vitamins or supplements you take. The following medicines have negative interactions with Z-Paks:

• Antacids that contain magnesium or aluminum
• Colchicine
• Amiodarone
• Disopyramide
• Dofetilide
• Dronedarone
• Ibutilide
• Pimozide
• Procainamide
• Quinidine
• Sotalol
• Warfarin

This is not a full list of drug interactions and others may occur. Talk to your doctor about drug interactions before taking azithromycin.

Note: There are no drug interactions between azithromycin and Nyquil, so you can safely take these two drugs together to ease symptoms of a cough, sore throat, headache, fever, runny nose, and sneezing. However, before taking NyQuil or any other cough/cold medication, check with your doctor or pharmacist if the medication is safe to take with your medical conditions and/or other medications you take. Many cough and cold medications are not safe for people with certain conditions, such as high blood pressure or glaucoma. 

What are the side effects of Z-Paks?

The most common Z-Pak side effects are:

• Diarrhea
• Nausea
• Abdominal pain/indigestion/gas
• Dizziness
• Headache
• Appetite loss
• Itching or rash
• Fatigue or tiredness
• Vomiting

Serious side effects of Z-Paks may include: 

• Hearing loss
• Worsening of myasthenia gravis (muscle weakness)
• Heart/heart rhythm problems
• Inflamed pancreas
• Liver problems/jaundice (yellowing of the skin and/or whites of the eyes)
• Severe stomach pain and/or severe, watery diarrhea which may indicate C. difficile-associated diarrhea (a severe diarrhea that can begin up to several months after antibiotic treatment) and requires immediate medical attention
• Severe skin reaction (be alert for blistering or peeling skin, red or purple rash, burning eyes, sore throat, fever) – this requires emergency medical attention
• A serious drug reaction that can affect many parts of the body (be alert for rash, fever, swollen glands, muscle aches, weakness, unusual bruising, and jaundice)

Seek medical help right away if you experience fainting, severe dizziness, a fast or irregular heartbeat, or an allergic reaction. Symptoms of an allergic reaction may include hives, difficulty breathing, and swelling of the face, lips, throat, or tongue. You should also seek medical treatment if any of these side effects persist or worsen.

Azithromycin has also caused abnormal changes in the electrical activity of the heart, which can lead to a potentially fatal irregular heart rhythm, according to the U. S. Food and Drug Administration (FDA). Patients at risk for developing this condition include those who have low blood levels of potassium or magnesium, have a slower-than-average heart rate, or use drugs that treat abnormal heart rhythms (arrhythmia).

If your baby is taking azithromycin and is irritable or vomits while eating or nursing, contact the pediatrician right away. 

Talk to your healthcare provider before taking a Z-Pak to discuss all possible side effects and drug interactions. He or she can provide medical advice on how to avoid or treat adverse effects. For example, taking this medicine with food could prevent an upset stomach.

Does a Z-Pak have to be taken with food?

Azithromycin can be taken with or without food. However, there are some steps you can take to help prevent or lessen the common side effects of diarrhea, nausea, and abdominal pain while taking azithromycin. 

According to family medicine physician Michael Rabovsky, MD, “The problem is that when you are trying to kill bacteria in your sinuses, lungs, or elsewhere, antibiotics also kill bacteria that live in your intestine that keep your digestive health in balance. ” Probiotics can help restore the good bacteria in your gut. “The thing that has really been shown to help the most with preventing diarrhea is taking probiotics when taking antibiotics,” Dr. Rabovsky says. 

Drinking plenty of water and staying hydrated with oral rehydration solutions can also help ease the effects of diarrhea. 

Are there alternatives to Z-Pak?

“The medications clarithromycin or Augmentin are sometimes used as alternatives to the Z-Pak,” according to Chirag Shah, MD, board-certified emergency medicine physician and co-founder of Push Health. “However, these alternatives will not always work to treat the infection for which the Z-Pak was prescribed in the first place, and consultation with one’s medical provider is recommended before changing medications.”

Azithromycin vs. amoxicillin

Amoxicillin is a common alternative to azithromycin. Amoxicillin can be prescribed alone, or as Augmentin, which contains amoxicillin and clavulanate. Clavulanate is added to amoxicillin to prevent resistance. Here’s a side-by-side comparison of how azithromycin and amoxicillin stack up against each other.

RELATED: Amoxicillin side effects and how to avoid them

More Z-Pak alternatives

In addition to amoxicillin, there are other alternatives to Z-Paks, such as:

• Cipro (ciprofloxacin): This affordable antibiotic is effective at treating bacterial infections, but it may have more interactions with food and drugs compared to other Z-Pak Alternatives. 
• Vibramycin (doxycycline): This antibiotic treats bacterial infections, like pneumonia, and prevents malaria. However, it may make you more sensitive to sunlight and result in sunburn or a rash.
• Keflex (cephalexin): Cephalexin is usually taken multiple times a day, which can be hard to remember for some people. It treats bone infections, UTIs, skin infections, and surgical site infections, among other bacterial infections.
• Cleocin (clindamycin): This drug is effective in treating acne, when used topically, especially when combined with other acne medications. It can also be used orally for serious skin or soft tissue infections. In some cases, clindamycin can cause severe diarrhea, which can be very serious or even fatal. 
• Levaquin (levofloxacin): This medicine, in the same class as Cipro, treats a variety of bacterial infections.
• Bactrim (sulfamethoxazole-trimethoprim): This medicine treats bacterial infections, but taking this medicine may make you more susceptible to sunburns.

What is a Z-Pak? Side Effects and More

Zithromax, sometimes called Z-Pak, is a popular form of the antibiotic azithromycin. Azithromycin is the most commonly prescribed antibiotic in the United States.

It is a macrolide antibiotic that treats some bacterial infections by stopping the growth of the bacteria. This process of stalling bacteria growth is why Z-Pak is called “bacteriostatic”—instead of killing bacteria outright, it stops them from growing and multiplying.

The body’s natural defenses can then remove what’s left of the bacteria. Azithromycin has no use in treating viral infections, including COVID-19, common colds, viral bronchitis, or most sinus infections. If you’re wondering what a Z-Pak (or Z-Pack) is, how to use this medication, or whether it’s effective, this guide will help.

In this article, I’ll discuss the Z-Pak’s uses, doseage, and effectiveness, as well as risks and side effects. I’ll talk about when not to take a Z-Pak, and some alternatives to Zithromax. I’ll finish by outlining when you should see a doctor about your symptoms.

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Z-Pak Uses

Azithromycin (Zithromax or Z-Pak) can be used to treat some bacterial infections of the skin, respiratory, and genitourinary system. Here are some infections for which your doctor may prescribe a Z-Pak.

Strep Throat

Strep throat, or streptococcal pharyngitis, is a bacterial infection of the throat. It typically manifests as a sore throat, pain with swallowing, as well as a fever or a rash.

Penicillin antibiotics are the preferred treatment for strep throat, but some patients are allergic to these antibiotics. In these cases, your doctor may prescribe Zithromax instead. Research has shown that Z-Paks treat strep throat just as well as penicillin for those with a penicillin allergy. Azithromycin does not work for viral throat infections. 

Pneumonia

Z-Pak is also effective for treating some types of community-acquired pneumonia, an acute respiratory infection contracted outside of the hospital. Studies show that for patients treated with azithromycin, hospital stays were shorter despite a shorter course of antiobiotics. 

Your provider may also choose to treat pneumonia with a combination of Z-Pak and another antibiotic for a stronger effect, as azithromycin does not treat all types of pneumonia well. Azithromycin does not work for COVID-19 pneumonia or other viral pneumonias.

Bronchitis

Bronchitis is an infection of the main chest airways called bronchi. While most bronchitis is caused by viruses, the infection is sometimes caused by bacteria. In these bacterial cases, Z-Pak may be useful for treatment. 

Most of the time, though, your doctor will probably not prescribe an antibiotic for bronchitis: A study in American Family Physician showed that antibiotics provide very little benefit in most cases of acute bronchitis.

However, when the bronchitis is caused by whooping cough or other specific bacteria, macrolides like Z-Pak are efficient for reducing the spread. 

Other Uses

Other bacterial infections that can be managed with azithromycin are:

• Bacterial sinusitis: According to a study comparing the impact of amoxicillin-clavulanate and azithromycin, Z-Packs can treat sinus infections caused by bacteria. However, most sinus infections are caused by viruses, and do not need antibiotics at all. And when sinusitis is caused by bacteria, other antibiotics are generally preferred and more effective.

• Tonsillitis: Z-Pak works for treating tonsillitis in adults and children who cannot take penicillin-based antibiotics, though it may have more side effects.

• Ear infections (otitis media): Azithromycin is also effective for treating infections of the middle ear that are caused by bacteria in those who cannot take other preferred antibiotics. 

• Mycobacterium Avium Complex (MAC) Lung Disease: Z-Pak is used to manage MAC lung disease, often seen in patients with HIV.

• Non-gonococcal urethritis: This inflammation of the male urethra, caused by the sexually-transmitted disease chlamydia, can be treated with azithromycin, though doxycycline is often the preferred antibiotic.

• Pelvic Inflammatory Disease (PID): PID should be treated with the antibiotic doxycycline, but in those who cannot take doxycycline, azithromycin may be used in combination with another antibiotic.  

• Cervicitis: Experts recommend either doxycycline or azithromycin for the treatment of chlamydial cervicitis, though doxycycline is the recommended treatment. When cervicitis is caused by gonorrhea, a different antibiotic is required.

• Lyme disease: The CDC recommends that people with early Lyme disease who cannot tolerate doxycycline, cefuroxime, or amoxicillin be treated with azithromycin—although it is less effective than the other three in this case.

Dosage of Zithromax

Azithromycin comes in various dosages, but a Z-Pak is a specific, five-day course of azithromycin. The Z-Pak contains six tablets, each containing 250 mg of azithromycin.

Two tables are taken on the first day (for a 500 mg dose), followed by one 250 mg tablet taken each of the next four days. This is a common dose for many types of infections. Azithromycin is available as oral tablets, oral suspension (liquid), and injections or intravenous (IV) medication.

Each of the available forms come in several strengths. 

• Oral tablets: Available as 250 mg and 500 mg tablets.
• Oral suspension: Available as 100 mg/5 mL and 200 mg/5 mL suspensions.
• Injection and IV: Available as 10 mL vial of 500 mg.

Your doctor will decide what dosage is appropriate for you depending on your age and the infection. The prescribed strength and form may also vary over the course of your treatment. 

For example, the recommended dose for strep throat is 500 mg oral tablets once on the first day, followed by 250 mg oral tablets for the next four days. But for non-gonococcal urethritis, it’s a one-time, 1000 mg dose. 

How Long to Take It

Take your azithromycin for the duration prescribed by your provider. Usually, this is between 3-10 days. Make sure to take the medication on time and complete the full treatment course before discontinuing the drug—even if you’ve begun to feel better.  

Starting and quitting the drug before the specified day can cause bacteria to become resistant to antibiotics.

Effectiveness of Azithromycin

Azithromycin is a versatile and highly effective antibiotic when used appropriately. It works well in treating a wide range of bacterial infections both in children and adults. 

Azithromycin is especially effective in treating some sexually transmitted infections, like chlamydia and chlamydia-related infections. One clinical showed that azithromycin showed a 98% eradication for chlamydia and other bacteria. 

Possible Risks and Side Effects of Azithromycin

The most common side effects of azithromycin are not life-threatening for most people. Still, it’s worth knowing what they are so you don’t panic, and can get help from your doctor if needed.

Side effects you may experience with azithromycin are:

• Upset stomach
• Loose stools or diarrhea
• Nausea
• Vomiting
• Dizziness or fainting
• Skin rash 
• Abdominal pain
• Vaginal itchiness from yeast overgrowth
• Headache
• Ringing ears
• Blurred vision
• Nervousness
• Liver problems

Drug Interactions

Azithromycin may interact with several other medications, causing them to be ineffective, or potentially causing serious side effects. Be sure to mention all your current medications to your prescriber before receiving a prescription for azithromycin.

A few drugs that interact with azithromycin are:

• Antidepressants
• Antipsychotic medications
• Anti-malarial medications 
• Heart rhythm medications
• Cholesterol-reducing medication
• Blood pressure medication
• Anti-diarrheal medications 
• HIV medicines

If you take any of these medications, your provider may need to prescribe alternative medication or recommend pausing them for the duration of your antibiotic treatment.

When to Not Take Azithromycin

In some cases, azithromycin is not the right choice. Here are some situations in which you should avoid azithromycin.

STIs

While azithromycin works for treating some sexually transmitted infections, specifically those caused by chlamydia, it should not be used to treat gonorrhea and syphilis, or trichomonas. 

The CDC recommends using ceftriaxone (Rocephin) injection to treat gonorrhea and benzathine penicillin (Bicillin) injections for syphilis.

The CDC also now recommends doxycycline as the first-line treatment for chlamydia, not azithromycin. If you have an allergy or other inability to take doxycycline, then azithromycin may be used.

Age

Children under six months of age should not be treated with azithromycin. Recent studies show that azithromycin is safe for use in the elderly.

Pregnant

While azithromycin does not cause fetal malformations in the uterus, it has been associated with an increased risk of miscarriage. 

Heart Problems

If you have heart problems—especially irregular heartbeats like QT prolongation—it would also be best to avoid using azithromycin. A study in the New England Journal of Medicine showed that use of the antibiotic increased the risk of sudden death linked to heart arrhythmias.

Viral Illnesses

Many common infections, including colds, sinus infections, bronchitis, and some ear and throat infections, are caused by viruses. Unfortunately, when your illness is caused by a virus, an antibiotic will not help at all, and can cause uncomfortable or serious side effects.  

Alternatives to Azithromycin

For those unable to use azithromycin or other macrolides such as erythromycin and clarithromycin, there are other antibiotics you can be prescribed instead.

Amoxicillin

Amoxicillin is a penicillin-like antibiotic that treats many of the same bacterial infections azithromycin does. Because of antibiotic resistance, it is sometimes used with clavulanate as amoxicillin-clavulanate (Augmentin). 

This broad-spectrum antibiotic treats everything from respiratory tract infections to gastrointestinal infections. And it is safe for most people, including those who are pregnant.

Doxycycline

Doxycycline (Monodox) is especially useful for urogenital infections such as chlamydia. Some studies have shown it to be more effective than azithromycin, and the CDC now recommends doxycycline as the first-line treatment for sexually transmitted infections caused by chlamydia. 

Ceftriaxone

Ceftriaxone (Rocephin) treats bacterial pneumonias, ear infections, and throat infections, and may be used instead of, or in addition to, azithromycin for some types of infections.

Your doctor or healthcare provider will make the best choice for you when they know which medications you’re on and which other medical conditions you have.

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When to See a Doctor

If you have worrying signs of an infection, it’s best to see your primary care physician before beginning antibiotic treatment using azithromycin. Many common infections are actually viral, and will resolve on their own without antibiotics.

Azithromycin is not the right treatment for all types of bacterial infections. Your provider can determine if antibiotics are needed at all, which antibiotics are safe and effective for your infection, and what dosage will work best.

If you have already begun using azithromycin and are not seeing improvement in your symptoms or are getting worse, speak to your healthcare provider.

How K Health Can Help

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Frequently Asked Questions

Are there good alternatives for Z-Pak (Zithromax)?

It depends on the type of infection! In general, there are many other antibiotic options that treat the bacterial infections that azithromycin is often used for. Your healthcare provider can help you figure out if an antibiotic is needed, and if azithromycin or another option is the correct choice.

Is azithromycin a steroid?

No. Azithromycin is a macrolide antibiotic that works by inhibiting the growth of bacteria.

Can Z-Pak be used to treat COVID-19?

No. Studies have shown that azithromycin does not treat COVID-19. COVID-19 is a viral infection, and azithromycin only treats bacterial infections. Azithromycin will not help with any viral illness, including COVID-19.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions,
and medical associations. We avoid using tertiary references.

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