Define hydroxyzine. Hydroxyzine: A Comprehensive Guide to the Versatile Antihistamine and Anxiolytic Medication

12.11.202123.07.2023 by alexxlab

What is hydroxyzine. How does hydroxyzine work. What are the main uses of hydroxyzine. What are the potential side effects of hydroxyzine. How is hydroxyzine administered. What precautions should be taken when using hydroxyzine. Are there any drug interactions with hydroxyzine.

Содержание

Understanding Hydroxyzine: Chemical Composition and Mechanism of Action

Hydroxyzine is a versatile medication with a chemical formula of C21H27ClN2O2. It belongs to the class of drugs known as antihistamines and also functions as a mild tranquilizer. But how exactly does this compound work in the body?

The primary mechanism of action of hydroxyzine involves its ability to block H1 histamine receptors. This action is responsible for its antihistamine effects, which help alleviate allergy symptoms. Additionally, hydroxyzine has anticholinergic properties and can cross the blood-brain barrier, contributing to its sedative and anxiolytic effects.

Chemical Structure and Properties

Hydroxyzine’s chemical structure consists of a piperazine ring linked to a hydroxyl group and a chlorophenyl ring. This unique arrangement allows the drug to interact with various receptors in the body, leading to its diverse therapeutic effects.

Molecular weight: 374.9 g/mol
Solubility: Soluble in water and alcohol
Half-life: Approximately 20 hours in adults

Therapeutic Applications: From Allergies to Anxiety

Hydroxyzine’s multifaceted nature makes it a valuable tool in treating various conditions. What are the primary uses of this medication?

Allergy symptom relief
Anxiety management
Sedation before medical procedures
Adjunct therapy for nausea and vomiting
Treatment of pruritus (itching)

In allergic conditions, hydroxyzine helps reduce symptoms such as itching, hives, and rhinitis. Its anxiolytic properties make it useful for managing generalized anxiety disorder and tension associated with psychoneurosis. Healthcare providers may also prescribe hydroxyzine as a sedative before surgery or other medical procedures.

Off-label Uses

While not FDA-approved for these purposes, some clinicians use hydroxyzine off-label for:

Insomnia
Migraine headaches
Restless leg syndrome

It’s important to note that off-label use should only be under the guidance of a healthcare professional.

Dosage Forms and Administration: Tailoring Treatment to Patient Needs

Hydroxyzine is available in various formulations to suit different patient needs and conditions. How is this medication typically administered?

The most common dosage forms include:

Oral tablets
Oral capsules
Oral suspension
Intramuscular injection

Dosages vary depending on the condition being treated, the patient’s age, and other individual factors. For example, adult doses for anxiety typically range from 25 to 100 mg four times daily, while antihistamine doses may be lower.

Pediatric Considerations

Hydroxyzine is also used in pediatric populations, with dosages adjusted based on the child’s weight. For children, the oral suspension form is often preferred due to ease of administration and dosage flexibility.

Side Effects and Precautions: Balancing Benefits and Risks

Like all medications, hydroxyzine can cause side effects. What are the most common adverse reactions associated with this drug?

Common side effects include:

Drowsiness
Dry mouth
Dizziness
Constipation
Blurred vision

More severe side effects, though rare, can include:

Irregular heartbeat
Seizures
Severe allergic reactions

Patients should be aware of these potential side effects and report any concerning symptoms to their healthcare provider promptly.

Special Precautions

Certain populations require special consideration when using hydroxyzine:

Elderly patients: More susceptible to anticholinergic side effects
Pregnant women: Use only if benefits outweigh potential risks
Patients with liver or kidney impairment: May require dosage adjustments

Drug Interactions: Navigating Combination Therapies

Understanding potential drug interactions is crucial for safe and effective use of hydroxyzine. Which medications may interact with hydroxyzine?

Hydroxyzine can interact with several types of drugs, including:

Other CNS depressants (e.g., benzodiazepines, opioids)
Anticholinergic medications
Certain antidepressants
QT-prolonging drugs

These interactions can lead to increased sedation, enhanced anticholinergic effects, or in some cases, potentially dangerous cardiac arrhythmias. Patients should always inform their healthcare provider about all medications they are taking, including over-the-counter drugs and supplements.

Alcohol Interaction

Alcohol can enhance the sedative effects of hydroxyzine. Patients are typically advised to avoid alcohol consumption while taking this medication.

Pharmacokinetics: Understanding Hydroxyzine’s Journey in the Body

To fully grasp hydroxyzine’s effects, it’s essential to understand its pharmacokinetics. How does the body process this medication?

Hydroxyzine is rapidly absorbed from the gastrointestinal tract after oral administration. It undergoes extensive first-pass metabolism in the liver, where it’s converted to its primary active metabolite, cetirizine. This metabolite is responsible for much of hydroxyzine’s antihistamine effects.

Onset of action: 15-30 minutes for oral doses
Peak plasma concentrations: 2 hours after oral administration
Duration of action: Up to 24 hours for antihistamine effects
Elimination: Primarily through urine as metabolites

Understanding these pharmacokinetic properties helps explain why hydroxyzine can have long-lasting effects and why dosing intervals are typically set at 6-8 hours.

Hydroxyzine in Veterinary Medicine: Extending Benefits to Animal Care

Interestingly, hydroxyzine’s utility extends beyond human medicine. How is this medication used in veterinary practice?

Veterinarians often prescribe hydroxyzine for dogs and cats to manage various conditions, including:

Allergic skin conditions
Motion sickness
Anxiety-related behaviors

As in humans, the medication helps reduce itching and inflammation associated with allergies. It can also provide mild sedation, making it useful for anxious pets during travel or stressful situations like thunderstorms.

Dosing Considerations in Animals

Dosages for animals are typically based on body weight and can vary depending on the species and condition being treated. As with any medication, hydroxyzine should only be given to pets under veterinary supervision.

Historical Context and Development: Tracing Hydroxyzine’s Journey

To fully appreciate hydroxyzine’s place in modern medicine, it’s worth exploring its historical context. When was hydroxyzine first developed, and how has its use evolved over time?

Hydroxyzine was first synthesized in the 1950s by chemists at Union Chimique Belge, now part of UCB (Union Chimique Belge) S.A. It was initially developed as an antihistamine but quickly found use as an anxiolytic due to its sedative properties.

1956: First clinical use of hydroxyzine
1957: FDA approval for use in the United States
1960s-1970s: Widely used as an anxiolytic and sedative
1980s onwards: Continued use, with increased focus on antihistamine properties

Over the decades, hydroxyzine has remained a valuable tool in the medical arsenal, particularly for its versatility in treating both physical and psychological symptoms.

Evolving Understanding of Mechanism

As pharmacological knowledge has advanced, so too has our understanding of how hydroxyzine works in the body. Recent research has shed light on its interactions with various neurotransmitter systems, helping to explain its diverse effects.

Comparative Analysis: Hydroxyzine vs. Other Antihistamines and Anxiolytics

To fully appreciate hydroxyzine’s place in the pharmacological landscape, it’s useful to compare it with other medications in its class. How does hydroxyzine stack up against other antihistamines and anxiolytics?

Hydroxyzine vs. Second-Generation Antihistamines

Unlike newer, second-generation antihistamines like cetirizine or loratadine, hydroxyzine:

Has more pronounced sedative effects
Is more likely to cause anticholinergic side effects
Can cross the blood-brain barrier more readily
Has anxiolytic properties not typically seen in newer antihistamines

These differences make hydroxyzine a preferred choice in situations where sedation is desirable, such as for sleep-disrupting allergies or pre-operative anxiety.

Hydroxyzine vs. Benzodiazepines

When compared to benzodiazepines, another class of anxiolytic medications, hydroxyzine:

Has a lower risk of dependence and abuse
Provides antihistamine effects in addition to anxiolytic properties
May have a more favorable side effect profile in some patients
Is often considered safer for long-term use

These factors make hydroxyzine an attractive option for managing chronic anxiety, particularly in patients with a history of substance abuse or those at risk for benzodiazepine dependence.

Future Perspectives: Hydroxyzine in Ongoing Research

Despite its long history, hydroxyzine continues to be a subject of scientific interest. What current research is being conducted on this versatile medication?

Several areas of ongoing research include:

Use in combination therapies for anxiety disorders
Potential applications in managing opioid withdrawal symptoms
Investigation of its effects on specific subtypes of anxiety disorders
Exploration of its potential neuroprotective properties

One particularly interesting avenue of research is the potential use of hydroxyzine in managing symptoms of autism spectrum disorders. Some preliminary studies have shown promise in reducing anxiety and improving sleep in children with autism, though more research is needed to confirm these findings.

Pharmacogenomics and Personalized Medicine

As the field of pharmacogenomics advances, researchers are also investigating how genetic factors might influence individual responses to hydroxyzine. This could potentially lead to more personalized prescribing practices, optimizing efficacy while minimizing side effects.

In conclusion, hydroxyzine remains a valuable and versatile medication in modern medicine. Its unique combination of antihistamine and anxiolytic properties, coupled with a generally favorable safety profile, ensures its continued relevance in treating a wide range of conditions. As research progresses, we may yet discover new applications for this long-standing pharmaceutical agent, further cementing its place in the therapeutic landscape.

Hydroxyzine Definition & Meaning – Merriam-Webster

hy·droxy·zine

hī-ˈdräk-sə-ˌzēn

: a compound C₂₁H₂₇ClN₂O₂ used as an antihistamine and tranquilizer

Example Sentences

Recent Examples on the Web

With the help of hydroxyzine, these symptoms can be greatly reduced, improving our dog’s quality of life.

—Amber Smith, Discover Magazine, 22 June 2023

Lyrica, oxycodone, nadolol, hydroxyzine, Cymbalta, gabapentin.

—William Wan, Washington Post, 12 June 2023

The Mercer County Prosecutor’s Office revealed Wednesday that the 20-year-old junior took her own life by ingesting a fatal dose of bupropion, escitalopram and hydroxyzine.

—Rebecca Rosenberg, Fox News, 29 Dec. 2022

Bupropion and escitalopram – known by the brand names Wellbutrin and Lexapro – are primarily prescribed for depression, while hydroxyzine is an antihistamine that treats allergies and anxiety.

—Rebecca Rosenberg, Fox News, 29 Dec. 2022

Smith-Fields’ autopsy results indicated that her cause of death was a combination of fentanyl, promethazine, hydroxyzine, and alcohol.

—Jenna Caldwell, Time, 17 Feb. 2022

In her purse, police found several medications, including tramadol, suspected Ambien, vitamin E, butalbital-acetaminophen-caffeine, ferrous sulfate, hydroxyzine hydrochloride and nadolol.

—Bob Sandrick, cleveland, 27 Dec. 2019

Tests by the Office of the Chief Medical Examiner showed Dustin died of acute intoxication from the combined effects of fentanyl, hydroxyzine and a compound used to make fentanyl called 4-ANPP.

—Jesse Leavenworth, courant.com, 19 Nov. 2019

An autopsy revealed the victim died from an overdose of hydroxyzine, fentanyl and morphine, the affidavit said.

—Nicholas Rondinone, courant.com, 24 May 2017

These examples are programmatically compiled from various online sources to illustrate current usage of the word ‘hydroxyzine. ‘ Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

hydroxy- + piperazine

First Known Use

1956, in the meaning defined above

Time Traveler

The first known use of hydroxyzine was
in 1956

See more words from the same year

Dictionary Entries Near

hydroxyzine

hydroxyurea

hydroxyzine

hydrozincite

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“Hydroxyzine.” Merriam-Webster. com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hydroxyzine. Accessed 23 Jul. 2023.

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Medical Definition

hydroxyzine

noun

hy·droxy·zine

hī-ˈdräk-sə-ˌzēn

: a compound that is administered usually in the form of its dihydrochloride C₂₁H₂₇ClN₂O₂·2HCl or pamoate C₂₁H₂₇ClN₂O₂·C₂₃H₁₆O₆ and is used as an antihistamine and tranquilizer

see vistaril

Last Updated:
30 Jun 2023
– Updated example sentences

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Merriam-Webster unabridged

Hydroxyzine HCl Oral: Uses, Side Effects, Interactions, Pictures, Warnings & Dosing

Uses

Hydroxyzine is used to treat itching caused by allergies. It is an antihistamine and works by blocking a certain natural substance (histamine) that your body makes during an allergic reaction. Hydroxyzine may also be used short-term to treat anxiety or to help you feel sleepy/relaxed before and after surgery.

How to use Hydroxyzine Hcl

Take this medication by mouth with or without food as directed by your doctor, usually three or four times daily. If you are using the liquid form of this medication, carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.

The dosage is based on your age, medical condition, and response to treatment. In children, the dosage may also be based on weight. Do not increase your dose or take this medication more often than directed.

Tell your doctor if your condition does not improve or if it worsens.

Side Effects

Drowsiness, dizziness, blurred vision, constipation, or dry mouth may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

To relieve dry mouth, suck (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as restlessness, confusion, hallucinations), shaking (tremor), difficulty urinating.

Get medical help right away if you have any very serious side effects, including: seizures, fast/irregular heartbeat, severe dizziness, fainting.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US – Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada – Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Precautions

Before taking hydroxyzine, tell your doctor or pharmacist if you are allergic to it; or to cetirizine; or to levocetirizine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: breathing problems (such as emphysema, asthma), high pressure in the eye (glaucoma), high blood pressure, kidney problems, liver problems, seizures, stomach/intestine problems (such as ulcer, blockage), overactive thyroid (hyperthyroidism), difficulty urinating (for example, due to enlarged prostate).

Hydroxyzine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before taking hydroxyzine, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/”water pills”) or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about taking hydroxyzine safely.

This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Liquid products may contain sugar and/or alcohol. Caution is advised if you have diabetes, liver disease, or any other condition that requires you to limit/avoid these substances in your diet. Ask your doctor or pharmacist about using this product safely.

Children may be more sensitive to the side effects of this drug. This drug can often cause excitement in young children instead of drowsiness.

Older adults may be more sensitive to the side effects of this drug, especially drowsiness, confusion, constipation, trouble urinating or QT prolongation (see above). Drowsiness and confusion can increase the risk of falling.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.

Interactions

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor’s approval.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or other antihistamines (such as diphenhydramine, promethazine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

Do not use with any other antihistamines applied to the skin (such as diphenhydramine cream, ointment, spray) because increased side effects may occur.

Hydroxyzine is very similar to cetirizine and levocetirizine. Do not use these medications while using hydroxyzine.

This medication may interfere with certain laboratory tests (including allergy skin testing, urine corticosteroids level), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

Does Hydroxyzine Hcl interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe drowsiness, seizures. In children, mental/mood changes (such as restlessness, irritability) may occur before drowsiness.

Do not share this medication with others.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Do not freeze liquid forms of this medication. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.