Hydroxyzine dosage, forms, and strengths

Medically reviewed by Anne Jacobson, MD, MPH
Board-Certified Family Physician
Updated Oct 21, 2025  •  Published Aug 10, 2023
Fact Checked
In this article:

Key takeaways

  • The standard hydroxyzine dosage for anxiety in adults is 50-100 mg four times daily.

  • The max dose of hydroxyzine is 400 mg/day.

  • Hydroxyzine is available as tablets, capsules, oral solution, or injections.

  • The best time to take hydroxyzine is three to four times daily spaced evenly apart.

  • Do not take hydroxyzine if you are in the early stages of a pregnancy, have a heart rhythm problem called QT prolongation, or are allergic to the drug.

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How much hydroxyzine should I take? Quick reference
Patient Typical starting dose Standard dosage Maximum dose
Anxiety in adults and adolescents 50-100 mg 4 times daily 50-100 mg 4 times daily 400 mg/day (oral) OR 600 mg/day (injection)
Itchy skin (pruritus) in adults 25 mg 3–4 times daily 25 mg 3–4 times daily 400 mg/day
Itchy skin in children and adolescents 50-100 mg/day divided into 3–4 doses 50-100 mg/day divided into 3–4 doses 100 mg/day

The dosages listed are general guidelines; your healthcare provider may adjust your dose based on individual health factors.

Hydroxyzine is a generic prescription antihistamine that treats anxiety, itchy skin, and nausea. Healthcare professionals also use hydroxyzine as a sedative before or after medical procedures. All these are FDA-approved conditions, but clinicians sometimes prescribe hydroxyzine off-label to treat other health conditions including occasional insomnia or seasonal allergies. Hydroxyzine formulations include tablets, capsules, or an oral solution, but a healthcare provider may administer an intramuscular injection in certain circumstances. Expect to take three or four doses a day.

Detailed hydroxyzine dosage chart for adults
Indication Starting dose Standard dose Maximum dose
Short-term treatment of anxiety, tension, or agitation 50-100 mg by mouth or intramuscular (IM) injection 50-100 mg by mouth or IM injection every 6 hours as needed 400 mg/day (by mouth) OR 600 mg/day (injections)
Itching due to hives or contact dermatitis 25 mg by mouth 25 mg by mouth every 6-8 hours as needed 400 mg/day
Nausea/vomiting 25-100 mg by IM injection 25-100 mg injection single dose every 6 hours as needed 400 mg/day
Sedation for anesthesia 25-100 mg by IM injection 25-100 mg injection given once N/A

Detailed hydroxyzine dosage chart for children

For anxiety and pruritus
Age Standard oral dose  Maximum dose
< 6 years old 50 mg per day taken in divided doses (every 6-8 hours) as needed 2 mg/kg/day for children who weigh less than 40 kg (88 lbs)
6-12 years old 50-100 mg per day taken in divided doses (every 6-8 hours) as needed 2 mg/kg/day for children who weigh less than 40 kg (88 lbs)
>12 years old Adult dosing

For nausea and vomiting
Age Standard oral dose  Standard IM dose 
<18 years of age Not FDA approved Off-label, same dose as for anxiety 1.1 mg/kg single dose MAXIMUM: 100 mg single dose

For procedural sedation
Age Standard oral dose Standard IM dose
<18 years of age 0.6 mg/kg single dose MAXIMUM: 100 mg single dose 1.1 mg/kg single dose  MAXIMUM: 100 mg single dose

How hydroxyzine works

Hydroxyzine for anxiety, tension, or agitation

Hydroxyzine is used short-term to relieve anxiety, tension, or agitation due to its sedative effects as an antihistamine. Histamines help keep the brain awake and active, so blocking histamines calms anxiety. Doctors use it to calm anxiety related to medical procedures, emotional stress, or withdrawal symptoms.

Hydroxyzine for itching (pruritus)

Hydroxyzine relieves itching by blocking histamines, chemicals involved in allergic reactions, helping treat chronic hives (urticaria), contact dermatitis, and eczema.

Hydroxyzine for nausea and vomiting

Hydroxyzine injections are FDA-approved for nausea and vomiting control. They are typically used before or after procedures, but oral forms are sometimes used off-label for this purpose.

Hydroxyzine for sedation

Healthcare professionals use hydroxyzine injections as sedation before medical, dental, or surgical procedures. It is often combined with other sedatives, such as benzodiazepines.

Hydroxyzine for insomnia

Hydroxyzine is sometimes prescribed off-label for temporary insomnia relief, but it is not FDA-approved for treating sleep disorders.

Personalized dosing considerations

Hydroxyzine doses are reduced by half for people with kidney dysfunction (creatinine clearance <50 mL/min) or on dialysis. No dosage restrictions or reductions exist for people with liver disease or hepatic impairment.

Hydroxyzine safety info

Hydroxyzine should be avoided in patients with a heart rhythm problem known as “prolonged QT interval” or who have known hypersensitivity to hydroxyzine, cetirizine, or levocetirizine. 

Hydroxyzine is contraindicated during the first three months of pregnancy. Breastfeeding women should avoid hydroxyzine.

People 65 and older may experience excessive sleepiness and confusion when taking hydroxyzine. They should consider hydroxyzine alternatives. 

Combining it with other sedatives or alcohol significantly increases sedation risks.

How to take hydroxyzine

People can take hydroxyzine at home as a tablet, capsule, or syrup. However, a healthcare professional will administer intramuscular injections.

You may take this medicine with food or on an empty stomach. If there are problems with an upset stomach, take hydroxyzine with food.

Store at room temperature in a container tightly sealed with a child-resistant cap. Protect the liquid versions from light and freezing.

Hydroxyzine hydrochloride vs. hydroxyzine pamoate: What’s the difference in doses?

There is no difference in dosages, indications, or side effects between hydroxyzine HCl and hydroxyzine pamoate. However, hydroxyzine pamoate is available only in one dosage form: capsules.

Hydroxyzine dosage FAQs

Can I take two hydroxyzine 25 mg at the same time?

Only take two or more 25 mg hydroxyzine tablets or capsules if you’re prescribed 50 mg or 75 mg doses. Do not exceed the prescribed dose.

Can I take 100 mg of hydroxyzine at once?

Yes, if you are prescribed 100 mg doses.

How long does it take hydroxyzine to work?

Hydroxyzine starts working within 15-60 minutes, with peak effects around two hours.

How long does hydroxyzine stay in your system?

Hydroxyzine remains in your system for about 14-25 hours. However, the therapeutic effects of hydroxyzine only last about four to six hours. 

What happens if I miss a dose of hydroxyzine?

Take the missed dose when remembered, but skip the missed dose if it's nearly time for the next dose.

Can you overdose on hydroxyzine?

Yes. Hydroxyzine overdose symptoms include severe drowsiness, difficulty breathing, or seizures. Seek immediate medical help.

What interacts with hydroxyzine?

Hydroxyzine has significant drug interactions with alcohol, barbiturates, opioids, muscle relaxants, benzodiazepines, antidepressants, and other over-the-counter or prescription drugs that make you sleepy (CNS depressants). Hydroxyzine can worsen anticholinergic drug side effects like dry mouth or urinary retention.

How do I stop taking hydroxyzine?

Stopping hydroxyzine will not cause withdrawal symptoms. Healthcare providers generally use hydroxyzine for only short periods—sometimes only a single dose—and discontinue the drug without a tapering dose.

What is the dosage of hydroxyzine for dogs and cats?

Veterinarians usually prescribe 0.5–2 mg/kg in dogs and cats as an oral medication or injection. Doses are based on the animal’s body weight. It relieves allergies and itching but may cause sedation. Veterinarians will usually first try more commonly used antihistamines like Benadryl (diphenhydramine), cetirizine, or levocetirizine. 

Sources

Medically reviewed by Anne Jacobson, MD, MPH
Board-Certified Family Physician

Anne Jacobson, MD, MPH, is a board-certified family physician, writer, editor, teacher, and consultant. She is a graduate of University of Wisconsin School of Medicine and Public Health, and trained at West Suburban Family Medicine in Oak Park, Illinois. She later completed a fellowship in community medicine at PCC Community Wellness and a master's in Public Health at the University of Illinois-Chicago. She lives with her family near Chicago.

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