Hydroxyzine
Pronunciation: (hye-DROX-i-zeen).
- Generic name
- hydroxyzine
- Brand names
- Vistaril, Hycin, Ucerax, Atarax, Hydil
- Drug class
- Antihistamine (First-generation)
Availability and supply rules vary by country
Trade names by country: Canada
Australia: · Full directory
What hydroxyzine is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how hydroxyzine works
Hydroxyzine is a first-generation antihistamine that acts as a potent antagonist at H1 histamine receptors. It also exhibits anticholinergic and sedative properties by crossing the blood-brain barrier and inhibiting activity in certain subcortical regions of the central nervous system. This leads to its anxiolytic and sedative effects, in addition to its anti-allergic action. Hydroxyzine is contraindicated in patients with a prolonged QT interval and in early pregnancy per FDA labeling; no FDA boxed warning applies to this medicine. (2)
What hydroxyzine is used for
Anxiety
Anxiety (2)
Pruritus
Pruritus (2)
Sedation
Sedation (2)
Insomnia
Insomnia (2)
Before taking hydroxyzine
Do not take / not appropriate for
- hypersensitivity to hydroxyzine or cetirizine, prolonged QT interval, and history of torsades de pointes or other serious arrhythmias. (Contraindication) (2)
- Avoid use in early pregnancy unless clearly necessary. (Contraindication) (2)
Tell your clinician about
(2)How to take hydroxyzine
- General Instructions: Take hydroxyzine exactly as prescribed by your healthcare provider. Do not take more or less than directed.. Adult Dosing: Typical adult doses range from 25 mg to 100 mg per day, divided into 2–4 doses depending on the condition being treated.. Pediatric Dosing: Children's doses are based on weight and age. For children over 6 years, the usual dose is 50–100 mg per day in divided doses. For children under 6 years, 50 mg per day in divided doses is typical.. Administration: Hydroxyzine can be taken with or without food. Oral forms should be swallowed whole with water. The injectable form is administered by a healthcare professional.. When To Stop: If you experience serious side effects or an allergic reaction, seek medical attention promptly — let the clinician you see advise on whether to continue or stop hydroxyzine.. Storage: Store at 20-25°C (68-77°F) (USP Controlled Room Temperature), away from moisture and heat. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (2)
Missed dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose. Do not take two doses at the same time.
Overdose
Symptoms of overdose may include extreme drowsiness, nausea, vomiting, seizures, or irregular heartbeat. Seek emergency medical attention immediately if overdose is suspected. (2)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Drowsiness
Incidence: Reported in the clinician-authored database; frequency not established
Dry mouth
Incidence: Reported in the clinician-authored database; frequency not established
Dizziness
Incidence: Reported in the clinician-authored database; frequency not established
Blurred vision
Incidence: Reported in the clinician-authored database; frequency not established
Constipation
Incidence: Reported in the clinician-authored database; frequency not established
Confusion
Incidence: Reported in the clinician-authored database; frequency not established
Urinary retention
Incidence: Reported in the clinician-authored database; frequency not established
QT prolongation
Incidence: Reported in the clinician-authored database; frequency not established
Serious warnings
May cause significant drowsiness or sedation — serious
Symptoms: May cause significant drowsiness or sedation. Risk of QT prolongation and serious heart rhythm disturbances. Use with caution in elderly patients due to increased risk of confusion and falls. May interact with other central nervous system depressants.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Contraindications recorded in the clinician database, refined against FDA labeling — serious
Symptoms: Contraindications recorded in the clinician database, refined against FDA labeling: hypersensitivity to hydroxyzine, or to cetirizine/levocetirizine (chemically related, cross-sensitivity risk), prolonged QT interval, and history of torsades de pointes or other serious arrhythmias. Hydroxyzine is FDA-labeled as CONTRAINDICATED in early pregnancy (not merely a caution) because human safety data in early pregnancy are inadequate — use in pregnancy is a decision for the clinician managing the pregnancy, not something to start or continue independently. Use with caution in patients with hepatic or renal impairment, elderly patients (due to increased risk of sedation and falls), and those with risk factors for QT prolongation.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Hydroxyzine can interact with other medications that cause drowsiness, such as opioids, benzodiazepines, and certain antidepressants. It may also interact with drugs that affect heart rhythm (e.g., some antipsychotics, antiarrhythmics). Always inform your healthcare provider about all medicines and supplements you are taking. |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
Contraindicated in early pregnancy per FDA labeling, because human safety data in early pregnancy are inadequate to establish safety. Tell your healthcare provider if you are pregnant, think you may be pregnant, or are planning a pregnancy — this decision requires clinician assessment of the specific situation, not self-directed use. (2)
Breastfeeding
Ask your healthcare provider for advice specific to your situation, since sedating antihistamines can pass into breast milk. (2)
Children
Frequency: For anxiety/tension and pruritus: 50 mg/day in divided doses for children under 6 years; 50-100 mg/day in divided doses for children over 6 years (per FDA labeling). A separate weight-based figure is also recorded: 0.5-1 mg/kg/dose (max 50 mg/dose), up to 2.5 mg/kg/day (max 300 mg/day), used in some dosing contexts (e.g., pre-anesthesia sedation, where labeling separately describes about 0.6 mg/kg). Max Single Dose: 50 mg. Age Restrictions: Not recommended for pediatric use under 6 months of age; safety not established in very young infants. (2)
Renal_impairment
Use with caution per the clinician database. Discuss any kidney or liver condition with the prescribing clinician before use. (2)
Hepatic_impairment
Use with caution per the clinician database. Discuss any kidney or liver condition with the prescribing clinician before use. (2)
Monitoring
(2)Storage
Store at 20-25°C (68-77°F) (USP Controlled Room Temperature), away from moisture and heat. Keep out of reach of children.
Study the drug class: Antihistamines
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General
Indication: Anxiety
Dose summary: Adults: 25 mg to 100 mg orally per day (divided into 2-4 doses), depending on the condition being treated. Pediatric: age-banded dosing per FDA labeling (see special_populations.children).
Renal context: Renal/hepatic-impairment-specific dose adjustment is not established in the clinician-authored database content or the FDA label reviewed; use with caution per the clinician database, individualized by the prescriber. (2)
Frequently asked questions
What is hydroxyzine used for?
Hydroxyzine is used to treat allergy symptoms (itching, hives), anxiety, tension, and as a sedative before or after anesthesia. It may also be used to help with sleep problems related to these conditions.
How quickly does hydroxyzine work?
Hydroxyzine usually begins to work within 15 to 60 minutes after taking an oral dose, with peak effects seen within 2 hours.
Can I take hydroxyzine with other allergy medications?
You should consult your healthcare provider before combining hydroxyzine with other allergy medications, especially other antihistamines, as this can increase side effects.
Is hydroxyzine safe during pregnancy?
No — hydroxyzine is FDA-labeled as contraindicated in early pregnancy because human safety data in early pregnancy are inadequate. Tell your healthcare provider if you are or might be pregnant so they can discuss safer alternatives with you.
Does hydroxyzine cause dependence or withdrawal?
Hydroxyzine is not habit-forming and does not cause dependence or withdrawal symptoms.
Can hydroxyzine be used for long-term anxiety treatment?
Hydroxyzine is typically used for short-term relief of anxiety symptoms. Long-term use should be discussed with your healthcare provider.
What should I do if I experience severe side effects?
Seek immediate medical attention if you experience severe side effects such as irregular heartbeat, severe drowsiness, confusion, or signs of an allergic reaction — let the clinician you see advise on whether to continue or stop hydroxyzine.
What happens if I take too much Hydroxyzine?
Taking too much Hydroxyzine can lead to severe drowsiness, confusion, blurred vision, dry mouth, and urinary retention. In more serious cases, it may cause seizures, hallucinations, or a dangerously irregular heartbeat. If you suspect an overdose, seek immediate emergency medical attention or contact poison control. Do not attempt to self-treat an overdose.
Can I drink alcohol while taking Hydroxyzine?
No, it is strongly advised to avoid alcohol while taking Hydroxyzine. As a first-generation antihistamine, Hydroxyzine can cause significant central nervous system depression, including drowsiness and impaired coordination. Combining it with alcohol will intensify these effects, leading to severe sedation, dizziness, and potentially dangerous impairment of motor skills and judgment. This combination increases the risk of accidents.
What is the mechanism of action of hydroxyzine?
Hydroxyzine is a first-generation antihistamine that acts as a potent antagonist at H1 histamine receptors. It also exhibits anticholinergic and sedative properties by crossing the blood-brain barrier and inhibiting activity in certain subcortical regions of the central nervous system. This leads to its anxiolytic and sedative effects, in addition to its anti-allergic action. Hydroxyzine is contraindicated in patients with a prolonged QT interval and in early pregnancy per FDA labeling; no FDA boxed warning applies to this medicine. (2)
What is the generic name of Hydroxyzine?
The generic name is hydroxyzine. It is sold under brand names including Vistaril, Hycin, Ucerax, Atarax, Hydil.
What class of drug is hydroxyzine?
Hydroxyzine is classed as: Antihistamine (First-generation).
References
- Hydroxyzine — clinician-authored medicine recordMedGuideGlobal Clinician-Authored Medicine Record (internal database) · Unspecified · accessed 2026-08-06 · source 1
- HYDROXYZINE HYDROCHLORIDE tablet — prescribing informationU.S. National Library of Medicine (DailyMed) / U.S. Food and Drug Administration · United States · accessed 2026-08-06 · source 2
- HYDROXYZINE PAMOATE CAPSULE [REMEDYREPACK INC.] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- Hydroxyzine — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 4
- hydroxyzine pamoate — FDA approval record (Drugs@FDA ANDA087479)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 5
- hydroxyzine — RxNorm normalized drug concept (RXCUI 154987)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 6
Brand names by country
Single-ingredient hydroxyzine names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
Canada
- ATARAX
- NOVO-HYDROXYZIN
- PMS HYDROXYZINE SYR