Schedule H

Oral, Intramuscular (IM)

• Tablets: 10 mg, 25 mg (as hydrochloride)

• Syrup: 10 mg/5 mL (as hydrochloride)

• Injection: 25 mg/mL in 2 mL ampoule (IM use only)

INDICATIONS + DOSING — FOR CLINICIAN USE ONLY

Primary Indications (Approved / Standard in India)

1. Pruritus / Urticaria / Allergic Dermatoses (Symptomatic Relief)

Step Dose Clinical Notes

Starting dose 25 mg at bedtime OR 10–25 mg twice daily Evening dosing preferred due to sedation

Titration Increase by 25 mg/day every 3–5 days as needed Based on symptom control and tolerability

Usual maintenance dose 25–50 mg/day in divided doses May give as single bedtime dose for nocturnal pruritus

Maximum dose 100 mg/day in divided doses Higher doses increase sedation and anticholinergic effects

Key points:

• Effective for histamine-mediated itch (urticaria, atopic dermatitis, drug reactions)

• Sedation can be therapeutic for pruritus-associated sleep disturbance

• Prefer non-sedating antihistamines (cetirizine, fexofenadine) for daytime use

1. Anxiety (Short-Term Symptomatic Relief)

Step Dose Clinical Notes

Starting dose 25–50 mg/day in divided doses Lower starting dose in anxious patients to assess tolerance

Titration Increase to 50–100 mg/day based on response Divide into 2–4 doses daily

Usual maintenance dose 50–100 mg/day in divided doses Typical: 25 mg TID or 50 mg BD

Maximum dose 100 mg/day Not for long-term use (>4 weeks)

Key points:

• Alternative to benzodiazepines for short-term anxiety management

• No dependence potential unlike benzodiazepines

• Not appropriate for panic disorder or severe generalised anxiety disorder

1. Preoperative Sedation (Adjunctive Use)

Route Dose Clinical Notes

Intramuscular 50–100 mg IM, 1 hour before procedure Deep IM injection only

Oral (alternative) 50–100 mg PO, 1–2 hours before procedure When IM not feasible

Key points:

• IM route only — NEVER administer IV or subcutaneously (risk of tissue necrosis, thrombosis)

• Reduces opioid and anaesthetic requirements

• Monitor for excessive sedation; have reversal measures available

Secondary Indications — Adults (Off-label)

Indication Dose Duration Notes

Alcohol Withdrawal-Associated Anxiety 25–50 mg TID–QID Short-term (<5 days) OFF-LABEL; Specialist only; Evidence: Indian psychiatry protocols; adjunct to reduce benzodiazepine requirement

Transient Insomnia 25–50 mg at bedtime Short-term (<7 days) OFF-LABEL; Evidence: Indian psychiatry/internal medicine practice; when other sedatives contraindicated

Nausea and Vomiting (adjunctive) 25–50 mg TID–QID Short-term OFF-LABEL; Limited evidence; used in palliative care settings

PAEDIATRIC DOSING (Specialist Only)

Primary Indications

1. Pruritus / Urticaria / Allergic Conditions

Age-Based Oral Dosing

1–6 years 5–10 mg/day in divided doses 15–25 mg/day in 2–3 divided doses 50 mg/day

6–12 years 10–15 mg/day in divided doses 25–50 mg/day in 2–3 divided doses 50 mg/day

≥12 years 25 mg/day 25–50 mg/day in divided doses 100 mg/day

Key points:

• Syrup formulation preferred for children <6 years (allows flexible dosing)

• Administer larger portion of dose at bedtime to minimise daytime sedation

• Start at lower end of dose range and titrate based on response

1. Preoperative Sedation (IM Route — Specialist/Anaesthetist Use)

Route Dose Maximum Single Dose

Intramuscular 0.5–1 mg/kg 50 mg

Administration: Give 1 hour before procedure; deep IM injection only

Secondary Indications — Paediatrics (Off-label)

Indication Dose Notes

Anxiety (short-term) 0.5–1 mg/kg/day in divided doses OFF-LABEL; Specialist only; Very limited paediatric data; avoid routine use

Safety monitoring:

• Monitor for excessive sedation, paradoxical excitation (more common in young children)

• Assess for anticholinergic effects (dry mouth, urinary retention, constipation)

• Heart rate monitoring if high doses used

Minimum age: Not recommended below 1 year of age due to risk of significant CNS depression and respiratory effects

Moderate impairment (eGFR 30–59) Start at lower end of dose range (e.g., 25 mg/day); titrate cautiously

Dialysis Not effectively removed; use with caution; give after dialysis if scheduled

• Known hypersensitivity to hydroxyzine, cetirizine (active metabolite), levocetirizine, or any excipient

• Prolonged QT interval (congenital or acquired)

• Concurrent use of other QT-prolonging drugs (see Major Drug Interactions)

• Porphyria (acute intermittent porphyria)

• Pregnancy (especially first trimester)

• Intravenous or subcutaneous administration (injection formulation is for IM use ONLY)

• Elderly patients — high anticholinergic burden; increased CNS sensitivity (see Elderly section)

• History of cardiac arrhythmias or significant cardiac disease

• Electrolyte abnormalities (hypokalaemia, hypomagnesaemia) — increased QT prolongation risk

• Narrow-angle glaucoma — anticholinergic effects may precipitate acute angle closure

• Prostatic hypertrophy or bladder neck obstruction — risk of urinary retention

• Myasthenia gravis — may exacerbate muscle weakness

• Epilepsy — may lower seizure threshold

• Hepatic or renal impairment — requires dose adjustment

• Concurrent use of CNS depressants (opioids, benzodiazepines, alcohol)

• Activities requiring alertness — warn about impaired driving and machine operation

Parameter Recommendation

Safety category Avoid use — teratogenicity concerns, particularly in first trimester

Preferred alternatives Chlorpheniramine (for allergies if antihistamine essential); loratadine or cetirizine (second-generation, non-sedating); non-pharmacological measures for pruritus

When it may be used Only in exceptional circumstances where benefit clearly outweighs risk and no alternatives available; requires specialist obstetric input

Monitoring If inadvertently used, fetal growth surveillance; neonatal observation for CNS depression and withdrawal symptoms

Parameter Recommendation

Compatibility Not recommended — excreted in breast milk; may cause infant sedation

Drug levels in milk Moderate (hydroxyzine and active metabolite cetirizine present)

Preferred alternatives Loratadine or cetirizine (second-generation antihistamines with better lactation safety data)

Infant monitoring If used, observe infant for sedation, irritability, poor feeding, CNS depression

• Recommended starting dose: 10 mg once or twice daily (lower than standard adult dose)

• Titration: Slow titration over 5–7 days; maximum usually 50 mg/day

• Additional risks:

• High anticholinergic burden — cognitive impairment, confusion, delirium

• Increased sedation and CNS depression

• Fall risk due to drowsiness and postural instability

• Urinary retention, constipation, dry mouth

• QT prolongation risk (often have concurrent cardiac disease/medications)

• Recommendation: Prefer second-generation (non-sedating) antihistamines (cetirizine, fexofenadine) when antihistamine required; avoid hydroxyzine if possible in patients ≥65 years (Beers Criteria)

Drug Interaction Management

QT-prolonging drugs (amiodarone, sotalol, haloperidol, droperidol, chlorpromazine, erythromycin, clarithromycin, moxifloxacin, ondansetron) Additive QT prolongation → risk of torsades de pointes AVOID combination; if essential, monitor ECG and electrolytes closely

MAO inhibitors Enhanced anticholinergic effects and CNS depression AVOID combination; wait 14 days after MAOI discontinuation

Opioid analgesics (morphine, fentanyl, tramadol) Profound CNS and respiratory depression AVOID combination or use with extreme caution; reduce opioid dose; monitor respiratory status

Benzodiazepines Additive sedation and CNS depression Use lower doses of both if combination necessary; monitor sedation

Alcohol Marked enhancement of CNS depression Advise complete abstinence during treatment

Drug Interaction Management

Other antihistamines (diphenhydramine, promethazine, chlorpheniramine) Additive anticholinergic and sedative effects Avoid overlapping use; if switching, allow washout

Tricyclic antidepressants (amitriptyline, imipramine) Potentiation of anticholinergic effects (dry mouth, constipation, urinary retention, confusion) Monitor for cumulative anticholinergic burden; consider alternatives

Anticholinergics (trihexyphenidyl, oxybutynin, ipratropium) Additive anticholinergic effects Monitor for toxicity; avoid in elderly

Antipsychotics (particularly phenothiazines) Additive sedation and anticholinergic effects; QT risk Monitor closely; consider ECG

Rifampicin CYP3A4 induction → reduced hydroxyzine efficacy May need higher hydroxyzine dose; monitor response

CNS depressants (gabapentin, pregabalin, muscle relaxants) Additive sedation Use with caution; warn patient

• Sedation / drowsiness (most common — dose-related)

• Dry mouth

• Dizziness

• Headache

• Blurred vision

• Constipation

• Fatigue

• Psychomotor impairment

Reaction Action Required

QT prolongation / Torsades de pointes Discontinue immediately; ECG monitoring; correct electrolytes; cardiology review

Seizures (especially in overdose or predisposed patients) Discontinue; supportive care; neurology input

Severe hypersensitivity (angioedema, anaphylaxis) Discontinue permanently; emergency management

Acute confusion / Delirium (especially elderly) Discontinue; supportive care; exclude other causes

Extrapyramidal symptoms (rare — dystonia, akathisia) Discontinue; may require anticholinergic treatment

Urinary retention (especially in prostatic hypertrophy) Discontinue or reduce dose; may need catheterisation

Note: In overdose, anticholinergic toxicity syndrome may occur (agitation, hallucinations, hyperthermia, tachycardia, urinary retention) — requires supportive care and possible physostigmine under specialist guidance

After initiation/dose change Assess sedation level at 3–7 days; ECG if high-risk patient

Long-term Not recommended for long-term use (>4 weeks) without specialist review; reassess need periodically; monitor for anticholinergic adverse effects

Single-ingredient products:

• Atarax (UCB/Dr. Reddy's) — tablets, syrup

• Hydroxyzine (generic — various manufacturers)

• Hyzine (Ranbaxy/Sun Pharma)

• Anxol (Alkem)

Note: Hydroxyzine is available as single-ingredient formulations; FDCs are not common

NLEM status: Not included in NLEM 2022 — not under NPPA price ceiling

• Sedation as therapeutic effect: Choose hydroxyzine when sedation is desirable (nocturnal pruritus, pre-procedure anxiety); avoid when daytime alertness required

• IM only — never IV: Injectable formulation must be given by deep IM injection only; IV or SC administration causes thrombosis, tissue necrosis, and gangrene

• Avoid in elderly: High anticholinergic burden; strongly consider second-generation antihistamines (cetirizine, levocetirizine, fexofenadine) as alternatives

• QT awareness: Hydroxyzine prolongs QT interval; avoid in patients with cardiac disease or on other QT-prolonging medications; consider ECG before use in at-risk patients

• Short-term use only: For anxiety, limit to 4 weeks; not a substitute for appropriate anxiolytics or psychotherapy

• Active metabolite: Cetirizine is the active metabolite of hydroxyzine — patients with prior cetirizine hypersensitivity should not receive hydroxyzine

antihistamine; first-generation; pruritus; urticaria; sedation; anxiolytic; preoperative sedation; QT prolongation; anticholinergic; elderly-avoid; pregnancy-contraindicated

RxIndia v1.1 — 14 Jun 2025

• CDSCO Approved Product Information

• Indian Pharmacopoeia 2022

• National Formulary of India

• API Textbook of Medicine (11th Edition)

• AIIMS Drug Formulary (Adult and Paediatric)

• IAP Treatment Guidelines

• Goodman & Gilman's The Pharmacological Basis of Therapeutics (13th Edition)

• Harrison's Principles of Internal Medicine (21st Edition)

• Indian Psychiatry Hospital Protocols (for off-label anxiety/insomnia use)