How Long does Hydroxyzine Stay in Your System?

Hydroxyzine is an antihistamine that is frequently used for conditions like anxiety or allergic reactions.

If you are taking hydroxyzine, you may wonder how long it will take to notice beneficial effects as well as how long hydroxyzine actually stays in your system.

In this article, we’ll explore how quickly hydroxyzine works and common side effects.

I’ll also go over possible alternative medications and how to know when you should see a doctor.

How Long Does Hydroxyzine Stay in Your System

Hydroxyzine is prescribed for allergic reactions or symptoms associated with allergies that are driven by histamine reactions (such as hives and itchy skin).

Anxiety, while not an allergic reaction, may also be driven by histamine receptors in the central nervous system (CNS).

Because of this common link, hydroxyzine may be prescribed and used effectively for both conditions.

A common side effect of hydroxyzine is drowsiness because of the way that it impacts the brain.

For acute allergy reactions or anxiety, hydroxyzine can be effective because it takes effect quickly.

Hydroxyzine usually provides symptom relief within 15-30 minutes of taking it.

The half-life is between 16-24 hours, but it may be shorter in children and longer in older adults or people with impaired kidney or liver function.

Because the effects peak at 2 hours, hydroxyzine may be prescribed to be taken 3-4 times per day, or every 6-8 hours. Always follow your prescription instructions.

If you stop taking hydroxyzine, the elimination half-life refers to how long it takes for the medication circulating in your body to be reduced by half.

In the case of hydroxyzine, it has a longer-lasting effect than diphenhydramine (Benadryl), another drug in the same class, which has a half-life of 3-9 hours.

How Quickly Does Hydroxyzine Start Working?

Depending on the dosage you were prescribed and the reason you are taking hydroxyzine, you may notice relief within 15-30 minutes.

Common Dosage Guide

Hydroxyzine is available by prescription as a generic drug, or as brand name drugs Vistaril or Atarax.

Dosage depends on the reason it was prescribed, symptoms, and other health conditions.

Your healthcare provider will use the lowest effective dosage to minimize side effects, such as drowsiness.

• Skin reactions or allergies: typically 25 mg, 3-4 times per day
• Anxiety symptoms or generalized anxiety disorder: typically 50-100 mg, up to 4 times per day

Hydroxyzine Side Effects

Hydroxyzine is associated with some common side effects, like many prescription drugs.

In some cases, they can be serious. Patients should report any side effects or reactions to a healthcare provider right away.

Always let your prescriber and pharmacist know if you take any other medicines, OTC drugs, or supplements.

This can help prevent avoidable interactions.

Common Side Effects

Hydroxyzine may cause some common mild side effects.

The higher the dosage, the more noticeable they may be.

They include:

• Drowsiness, daytime sleepiness, and fatigue
• Headache
• Dizziness
• Dry mouth
• Constipation
• Confusion

More Serious Side Effects

Hydroxyzine can also cause some serious side effects.

This is especially true if it is taken incorrectly or taken with certain medications.

Hydroxyzine is not safe for certain health conditions.

Be sure that your healthcare provider and pharmacist are aware of your medical history and anything that you take, including:

• Other medicines
• Over-the-counter drugs
• Supplements, vitamins, and herbs

If you experience any severe side effects, discontinue use right away and seek medical attention.

The following are not a full list of severe side effects associated with hydroxyzine:

• Rash
• Skin redness
• Pus-filled or blister-like sores
• Seizures
• Unintentional tremoring, trembling, or shaking
• Fever

Older people may be at higher risk for side effects, as well as those who have liver or kidney disorders, or certain heart conditions.

Hydroxyzine overdose is possible if you take more than is prescribed.

This can be serious and life-threatening. If you accidentally or intentionally take too much hydroxyzine, call 911 immediately.

If you’re having a mental health emergency, call 911 or go to the nearest emergency room. You can also get free 24/7 support from a suicide and crisis expert by calling or texting 988. If you’d prefer to chat online, you can chat with a suicide and crisis expert by visiting the Lifeline Chat.

Hydroxyzine Withdrawal Symptoms

Hydroxyzine is not associated with common withdrawal symptoms.

People who take it long-term or are used to its benefits may notice more symptoms when discontinuing.

Unless you have a severe allergic reaction, do not discontinue medication without first consulting your healthcare provider.

Is Hydroxyzine Habit-Forming?

Hydroxyzine is an antihistamine and is not a controlled substance. It is not habit-forming.

Hydroxyzine Alternatives

In some cases, hydroxyzine may not be indicated due to certain medical conditions or other prescriptions a patient already takes.

Some possible alternatives for hydroxyzine include:

• For allergic reactions: Diphenhydramine (Benadryl), desloratadine (Clarinex), fexofenadine (Allegra), or loratadine (Claritin)
• For anxiety or panic attacks: Alprazolam (Xanax)

Alprazolam is a controlled substance. It can be habit-forming and addictive.

Hydroxyzine is often a preferred anxiety treatment, but Xanax may be preferable if the patient has medical conditions that are not compatible with hydroxyzine. 

When to See a Doctor

See a healthcare provider for medical advice if you have questions about hydroxyzine or any of the conditions it may treat.

Your healthcare provider may recommend hydroxyzine for conditions or symptoms associated with high histamine levels, such as allergies.

They may also suggest it for acute anxiety episodes or generalized anxiety disorder.

Whether your quality of life is impacted by allergies or anxiety, your healthcare provider will help formulate a plan to address your symptoms.

Hydroxyzine, other medications, or lifestyle suggestions may all help to improve how you feel.

How K Health Can Help

Think you might need a prescription for Vistaril (hydroxyzine)?

K Health has clinicians standing by 24/7 to evaluate your symptoms and determine if hydroxyzine is right for you.

Get started with our free assessment, which will tell you in minutes if treatment could be a good fit. If yes, we’ll connect you right to a clinician who can prescribe medication and have it shipped right to your door.