Hydroxyzine Side Effects

Medically reviewed by Drugs.com. Last updated on Apr 15, 2025.

Applies to hydroxyzine: oral capsule, oral syrup, oral tablet.

Other dosage forms:

• intramuscular solution

Precautions

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to use it.

Call your doctor if your symptoms do not improve or if they get worse.

Make sure your doctor knows if you are pregnant. Do not use this medicine during the early part of a pregnancy unless your doctor tells you to.

This medicine may make you dizzy or drowsy. Do not drive or do anything that could be dangerous until you know how this medicine affects you.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for allergies or colds, sedatives, tranquilizers or sleeping medicine, prescription pain medicine or narcotics, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using this medicine.

Contact your doctor right away if you have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem such as QT prolongation.

This medicine may cause a serious skin condition called acute generalized exanthematous pustulosis (AGEP). Tell your doctor if you have a fever, skin rash, or worsening of skin problems after using this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Common side effects of hydroxyzine

Some side effects of hydroxyzine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Serious side effects of hydroxyzine

Along with its needed effects, hydroxyzine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking hydroxyzine:

Get emergency help immediately if any of the following symptoms of overdose occur while taking hydroxyzine:

Symptoms of overdose

• decreased awareness or responsiveness
• drowsiness
• nausea
• seizures
• severe sleepiness
• vomiting

For healthcare professionals

Applies to hydroxyzine: compounding powder, intramuscular solution, oral capsule, oral suspension, oral syrup, oral tablet.

General adverse events

The most commonly reported side effects included sleepiness, headache, and tiredness.^[Ref]

Nervous system

• Very common (10% or more): Sleepiness (up to 13.74%)
• Common (1% to 10%): Headache
• Rare (0.01% to 0.1%): Convulsion, tremor
• Frequency not reported: Anticholinergic activity, central nervous system (CNS) depression, drowsiness, incoordination, involuntary motor activity, psychomotor impairment, stimulation
• Postmarketing reports: Dizziness, dyskinesia, dystonia, paresthesia, sedation, seizures, syncope^[Ref]

Other

• Common (1% to 10%): Tiredness
• Frequency not reported: Antimuscarinic effects, lassitude
• Postmarketing reports: Asthenia, malaise, pyrexia, sudden death^[Ref]

Gastrointestinal

• Common (1% to 10%): Dry mouth
• Postmarketing reports: Constipation, diarrhea, nausea, vomiting^[Ref]

Cardiovascular

• Frequency not reported: QT prolongation, Torsade de Pointes
• Postmarketing reports: Cardiac arrest, cardiac arrhythmias, edema, hypotension, ventricular arrhythmias, ventricular fibrillation, ventricular tachycardia^[Ref]

Hypersensitivity

• Frequency not reported: Hypersensitivity reaction
• Postmarketing reports: Allergic reaction, anaphylactic shock, angioedema, hypersensitivity^[Ref]

Respiratory

• Frequency not reported: Respiratory depression
• Postmarketing reports: Bronchospasm^[Ref]

Dermatologic

• Postmarketing reports: Acute generalized exanthematous pustulosis (AGEP), bullous condition (pemphigoids, toxic epidermal necrolysis), dermatitis, erythema, erythema multiforme, fixed drug eruptions, increased sweating, maculopapular rash, pruritus, rash, Stevens-Johnson syndrome, urticaria^[Ref]

Psychiatric

• Postmarketing reports: Aggression, agitation, confusion, depression, disorientation, hallucination, insomnia, tics^[Ref]

Genitourinary

• Postmarketing reports: Dysuria, enuresis, urinary retention^[Ref]

Ocular

• Postmarketing reports: Accommodation disorder, blurred vision, oculogyric crisis^[Ref]

Hepatic

• Postmarketing reports: Hepatitis, liver function tests abnormal^[Ref]

Hematologic

• Postmarketing reports: Thrombocytopenia^[Ref]

Metabolic

• Postmarketing reports: Weight gain^[Ref]

See also:

Frequently asked questions

• Can you take hydroxyzine for anxiety and sleep?
• Can hydroxyzine be taken long-term?
• Does Benadryl help with or cause anxiety?
• Can dogs take hydroxyzine?
• When can I start drinking if I’m no longer taking hydroxyzine?
• Can you take antihistamines when pregnant?

Further information

Hydroxyzine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer