HYDROXYZINE HYDROCHLORIDE

Posology Hydroxyzine should be used at the lowest effective dose and for the shortest possible duration. In adults and children over 40 kg in weight, the maximum daily dose is 100 mg per day. Anxiety Adults 50-100mg daily in divided doses Pruritus Adults Starting dose of 25mg at night increasing as necessary to 25mg three or four times daily.

4). A reduced dose is advised. 2 ‘Pharmacokinetic properties’). Paediatric Population In children up to 40 kg in weight, the maximum daily dose is 2 mg/kg/day. From 6 months to 6 years, 5-15mg daily in divided doses adjusted depending on the child’s weight.

In children and adolescents over 40kg in weight, the maximum daily dose is 100mg per day. For children over 6 years, starting at 15-25mg and increasing to 50-100mg daily in divided doses adjusted according to the child’s weight. As with all medications, the dosage should be adjusted according to the patient's response to therapy.

Hepatic impairment The total daily dose should be reduced by 33%. 4 ‘Special Warnings and Precautions for Use’). 4 'Special Warnings and Precautions for Use'). Method of administration: oral.

The most common adverse effect of the sedating antihistamines is CNS depression. Effects vary from slight drowsiness to deep sleep, and include lassitude, dizziness, and incoordination. Paradoxical stimulation may occasionally occur, especially at high doses and in children and the elderly.

If sedative effects occur, they may diminish after a few days of treatment. Other common adverse effects include headache, psychomotor impairment and antimuscarinic effects. Undesirable effects are listed by MedDRA System Organ Classes.

Assessment of undesirable effects is based on the following frequency groupings:

Very common: ≥1/10 Common: ≥1/100 to <1/10 Uncommon: ≥1/1,000 to <1/100 Rare: ≥1/10,000 to <1/1,000 Very rare: <1/10,000 Not known: cannot be estimated from the available data System Organ Class Undesirable Effect Frequency Blood and lymphatic system disorders blood disorders, including agranulocytosis, leucopenia, haemolytic anaemia, and thrombocytopenia Not known Immune system disorders hypersensitivity reactions, anaphylaxis, angioedema Not known Metabolic and nutritional disorders porphyria, anorexia Not known Psychiatric disorders agitation, confusion, disorientation, hallucinations, sleep disturbances, depression, increased anxiety, nightmares Not known Nervous system disorders dyskinesia4, insomnia, sedation, drowsiness, dizziness, weakness, headache, tremor1 convulsions2, psychomotor impairment, paraesthesias, extrapyramidal effects, seizure, coma, somnolence.

g. 4), tachycardia, palpitation Not known Vascular disorders hypotension, flushing Not known Respiratory, thoracic and mediastinal disorders respiratory tract secretions, wheezing, nasal stuffiness, dryness of throat Not known Gastrointestinal disorders constipation, dryness of the mouth, nausea, vomiting, increased gastric reflux, diarrhoea, epigastric pain, increased GI peristalsis Not known Hepatobiliary disorders liver dysfunction Not known Skin and subcutaneous tissue disorders dermatitis, fixed drug eruption, pruritis, erythema, papular rash, sweating increased, urticaria, hair loss, eczema, acute generalised exanthematous pustulosis (AGEP), toxic epidermal necrolysis Stevens-Johnson syndrome, erythema multiforme Not known Muscoskeletal and connective tissue disorders myalgia Not known Renal and urinary disorders urinary retention, dysuria Not known Reproductive system and breast disorders priapism, impotence, early menses Not known General disorders and administration site conditions fatigue, malaise, lassitude, pyrexia, dryness of respiratory mucosae, asthenia, tightness of chest, irritability, chills Not known Investigations liver function tests abnormal, weight increased Not known Footnotes 1,2, 3 reported usually with doses considerably higher than those recommended.

1 ‘List of excipients’) • Patients with a known acquired or congenital QT interval prolongation. 5). 6 ‘Fertility, pregnancy and lactation’) Contains lactose. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.

3 ‘Contraindications’). Clinical data in humans are inadequate to establish safety in early pregnancy. The use of sedating antihistamines in the latter part of the third trimester may cause adverse effects in neonates such as irritability, paradoxical excitability, and tremor.

Animal studies have shown reproductive toxicity. Foetal abnormalities have been reported when hydroxyzine was administered, at doses substantially above the human therapeutic dose, to the pregnant mouse, rat and rabbit. Hydroxyzine crosses the placental barrier which may lead to higher foetal than maternal concentrations.

The following events were observed in a neonate whose mother received high dose (600mg per day) hydroxyzine during pregnancy; hypotonia, movement disorders including extrapyramidal disorders, clonic movements, tachypnea and poor feeding.

In neonates whose mothers received hydroxizine during late pregnancy and/or labour, the following events were observed immediately or only a few hours after birth: hypotonia, movement disorders including extrapyramidal disorders, clonic movements, CNS depression, neonatal hypoxic conditions or urinary retention.

Lactation It is expected that hydroxyzine may be excreted into breast milk. The effects on the nursing infant are unknown. 3 ‘Contraindications’).