Prescription first-generation antihistamine used for the management of anxiety, pruritus, and as a preoperative sedative. Available in two salt forms: hydroxyzine pamoate (Vistaril) typically used for anxiety, and hydroxyzine hydrochloride (Atarax) for pruritus. Offers anxiolytic effects without the dependence risk of benzodiazepines. Its active metabolite cetirizine is a second-generation antihistamine. Dosage must be determined by your prescribing physician.
Known hypersensitivity to hydroxyzine or cetirizine1,2
Early pregnancy
The bottom line
Evidence rating moderate. Most-documented uses: anxiety relief, no dependence or abuse potential, pruritus relief. 10 sources indexed (1996–2026), with 3 interaction records on file.
The science
How it works, mechanistically.
Core mechanism
Antagonizes histamine H1 receptors in the central nervous system, producing sedative, anxiolytic, and antiemetic effects. Also has anticholinergic (muscarinic antagonism) and antiserotonergic properties. Does not interact with GABA receptors, so it has no abuse or dependence potential.9
Class
Non-Benzodiazepine Anxiolytic
Dosing
Dosing & protocol.
Common range
25–100 mg up to four times daily (as prescribed by your physician)
Recommended form
Capsule, tablet, oral solution, or intramuscular injection
Rapidly absorbed orally. Can be taken with or without food. Onset of effect within 15–30 minutes.
Safety
Full safety detail.
Side effects
Drowsiness
Dry mouth
Dizziness
Headache
Constipation
Blurred vision
Contraindications
Known hypersensitivity to hydroxyzine or cetirizine1,2
Alcohol can markedly worsen hydroxyzine-related drowsiness, slowed reaction time, and clumsiness. In a controlled crossover trial, hydroxyzine taken with alcohol produced the greatest and most persistent psychomotor impairment among tested antihistamine-alcohol combinations. Risk is higher with higher hydroxyzine doses, older age, sleep apnea, lung disease, or other CNS depressants.
Recommendation: Do not drink alcohol when taking hydroxyzine for allergy, itching, anxiety, or sleep. If you already drank, avoid non-urgent hydroxyzine dosing and do not drive until fully alert. Seek urgent help for severe sleepiness, fainting, confusion, or slow breathing.
THC-dominant cannabis can compound hydroxyzine's sedating and attention-slowing effects. Hydroxyzine has measurable next-day and same-day cognitive effects in human studies, and THC acutely impairs psychomotor performance and driving-related skills. The combination is more concerning in people who are cannabis-naive, taking higher hydroxyzine doses, or using other sedatives.
Recommendation: Avoid combining THC-dominant cannabis with hydroxyzine when you need to be alert. If both were used, do not drive or do hazardous work until the effects have clearly worn off. Consider separating cannabis use from hydroxyzine therapy or using a less sedating allergy treatment if appropriate.
Melatonin can add to hydroxyzine's sedating effects, especially when hydroxyzine is used at night for itching, anxiety, or sleep. Hydroxyzine can impair cognition after morning dosing and can leave residual impairment after evening dosing, while melatonin can increase sleepiness and affect performance in some settings. The combined effect can matter for older adults and people who need to drive early the next day.
Recommendation: Avoid routine use of melatonin on top of hydroxyzine unless your prescriber agrees. If combined, use the lowest effective melatonin dose and avoid alcohol or other sedatives. Do not drive the next morning if you feel groggy, slowed, or unsteady.
Tsuchiya K, Miyamoto R, Tsunoda T et al.. Impact of atropine and hydroxyzine pretreatment in contemporary bronchoscopy. Respiratory investigation. 2026
Morrow RL, Mintzes B, Souverein PC et al.. Hydroxyzine Initiation Following Drug Safety Advisories on Cardiac Arrhythmias in the UK and Canada: A Longitudinal Cohort Study. Drug safety. 2022
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