Drug reference

Hydroxyzine

Antihistamine

Also known as Hydroxyzine hydrochloride

Antihistamine

CDSCO approved

EXCRETION

—

not curated

INTERACTIONS

12 major

SEVERE in our sources

PREGNANCY

Most manufacturers advise avoiding use during pregnancy. No evidence of teratogenicity. Use in latter part of third trimester may cause adverse effects in neonates (e.g., irritability, paradoxical excitability, and tremor).

FDA category + note

Top interactionssee all 12 →

AlcoholSevereDatabase
AlfentanilSevereDatabaseDDInter
AmiodaroneSevereDatabaseDDInter
AmisulprideSevereDatabaseDDInter

Mechanism

Hydroxyzine is a sedating antihistamine which exerts its actions by antagonising the effects of histamine.

Indications

Pruritusanxiety (short-term sedation)acute muscle dystoniaanxiety (associated with autonomic manifestations)Interstitial Cystitis/Bladder Pain Syndrome (off-label, limited evidence)pruritus control in Atopic Dermatitisimprove sleep in AD patients due to sedation

Dosing

Adult: BY MOUTH: Initially 25 mg daily, dose to be taken at night; increased if necessary to 25 mg 3–4 times a day.
Pediatric: BY MOUTH: Child 6 months–5 years: 5–15 mg daily in divided doses, dose adjusted according to weight; maximum 2 mg/kg per day. Child 6–17 years (body-weight up to 40 kg): Initially 15–25 mg daily in divided doses, dose increased as necessary, adjusted according to weight; maximum 2 mg/kg per day.…
Geriatric: BY MOUTH: Initially 25 mg daily, dose to be taken at night; increased if necessary to 25 mg twice daily. Maximum daily dose is 50 mg (if use cannot be avoided).
Max dose: Adults: 100 mg per day. Elderly: 50 mg per day. Children (body-weight up to 40 kg): 2 mg/kg per day.

Pharmacokinetics

Bioavailability

—

Protein binding

—

Excretion

—

Contraindications

Prolonged QT-interval (acquired or congenital)
Predisposition to QT prolongation
Risk factors for QT-interval prolongation (e.g., concomitant use of drugs that prolong the QT-interval, cardiovascular disease, family history of sudden cardiac death, significant electrolyte imbalance including low plasma-potassium or plasma-magnesium concentrations, significant bradycardia)
Elderly patients (due to increased susceptibility to side-effects; use should be avoided)

Side effects

Common

DrowsinessSedating effectsDistressEpistaxisFatigueHeadacheHyperhidrosisInsomniaLabyrinthitisMenstruation irregularMood alteredNasal complaintsNauseaOedemaPalpitationsParaesthesiaPhotosensitivity reactionSkin reactionsTinnitusTremorUrinary disordersVertigoVision disordersVomitingWeight increasedWheezingsedationdiminished alertnesslight headednessmotor incoordinationtendency to fall asleepdry mouthalteration of bowel movementurinary hesitancyblurring of visionsedation (can become bothersome)

Serious

Haemolytic anaemia
Hallucination
Hepatic disorders
Hypotension
Leucopenia
Neuritis
Seizure
Thrombocytopenia
QT-interval prolongation
Torsade de pointes
Adverse effects in neonates (e.g., irritability, paradoxical excitability, and tremor) if used in latter part of the third trimester
teratogenic in animals (caution in pregnancy)

Pregnancy & lactation

Pregnancy

Lactation

Most antihistamines are present in breast milk; although not known to be harmful, most manufacturers advise avoiding their use in mothers who are breast-feeding.

Drug interactions

Alcohol

Severe

Database

Increased sedation, dizziness, impaired psychomotor function, respiratory depression

Advise patients to avoid alcohol consumption while taking hydroxyzine.

Alfentanil

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Amiodarone

Severe

Database

Drug interaction classified as: synergy.

Source: DDInter

Amisulpride

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Anagrelide

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Antiarrhythmics (e.g., Amiodarone, Quinidine)

Severe

Database

Increased risk of QT prolongation and Torsades de Pointes.

Avoid concomitant use. If unavoidable, monitor ECG for QT prolongation and consider alternative antiarrhythmics or antihistamines.

Antipsychotics (e.g., Haloperidol, Risperidone)

Severe

Database

Increased sedation, increased risk of anticholinergic side effects, and increased risk of QT prolongation and arrhythmias.

Avoid concomitant use due to additive CNS depression, anticholinergic effects, and potential for QT prolongation. If unavoidable, monitor closely for adverse effects and consider ECG monitoring.

Arsenic Trioxide

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Azole Antifungals (e.g., Ketoconazole, Itraconazole)

Severe

Database

Increased risk of hydroxyzine-induced QT prolongation and Torsades de Pointes. Increased sedation.

Avoid concomitant use. If unavoidable, monitor ECG for QT prolongation and consider alternative antifungals or antihistamines.

Barbiturates (e.g., Phenobarbital)

Severe

Database

Profound sedation, respiratory depression, hypotension, coma.

Avoid concomitant use. If unavoidable, use the lowest effective doses of both drugs and monitor closely for CNS depression and respiratory depression.

Benzhydrocodone

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Benzodiazepines

Severe

Database

Profound sedation, respiratory depression, hypotension, coma

Avoid concomitant use. If unavoidable, use the lowest effective doses of both drugs and monitor closely for CNS depression. Consider alternative anxiolytics.