ATARAX Film-coated tablets Ref.[7284] Active ingredients: Hydroxyzine

Posology

Atarax 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.

Elderly

In the elderly, the maximum daily dose is 50 mg per day (see section 4.4). A reduced dose is advised. This is due to a possible increase in the volume of distribution, prolonged action and the possible effect of age-related changes on pharmacologic functions, including hepatic metabolism and renal excretion (see Section 5.2 ‘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%. Use in patients with severe liver disease should be avoided (see Section 4.4 ‘Special Warnings and Precautions for Use’)

Renal impairment

For patients with moderate or severe renal impairment, it is recommended that the total daily dosage should be reduced by 50% (see section 4.4 ‘Special Warnings and Precautions for Use’).

Method of administration

Oral.

Overdosage with sedating antihistamines is associated with antimuscarinic, extrapyramidal, and CNS effects. If CNS stimulation predominates over CNS depression, ataxia, excitement, seizures, tremors, psychoses, hallucinations, convulsions and hyperpyrexia can occur. Coma and cardiorespiratory collapse may follow. CNS stimulation is more likely in children and elderly. In adults, CNS depression is more common with drowsiness, postictal depression, coma, and convulsions, progressing to respiratory failure and cardiovascular collapse. In children and adults, cerebral oedema and upper nephron nephrosis, a deepening coma, tachycardia, QRS widening, heart block, cardiorespiratory collapse/arrest, cardiogenic shock, and death may occur.

Common features include excessive sedation, nausea, vomiting, flushing, dilated pupils, dry mouth and tongue, hot dry skin, fever, sinus tachycardia, hypertension, ataxia, nystagmus, delirium, agitation, psychosis and visual hallucinations. Uncommon systemic features include myoclonic jerking, muscle rigidity, coma, convulsions, cardiac conduction abnormalities, QT prolongation and arrhythmias, cardiovascular collapse, paralytic ileus, urinary retention, hyperkalaemia, metabolic acidosis and rhabdomyolysis.

Peak concentrations occur approximately two hours post ingestion, and elimination half-life has been reported approximately 14 hours and 20 hours post ingestion (see section 5.2 ‘Pharmacokinetic properties’).

There is no specific antidote. It is doubtful whether haemodialysis or peritoneal dialysis has any value in the treatment of overdosage with Atarax. However, if other agents such as barbiturates have been ingested concomitantly, dialysis may be indicated.

Consider activated charcoal only if the patient presents within 1 hour of ingestion of a potentially toxic amount. Gastric lavage is rarely required; for substances that cannot be removed effectively by other means, it should be considered only if a life-threatening amount has been ingested within the previous hour. It should be carried out only if the airway can be protected adequately. Induction of emesis is not recommended.

General supportive care, including frequent monitoring of the vital signs and close observation of the patient is indicated. Clear airways should be maintained, and there should be adequate ventilation. Assisted ventilation is indicated if hypercapnia is present. Observation for 6 hours after ingestion, without any other specific treatment, will be sufficient for the majority of patients. Monitor BP, pulse and body temperature. In symptomatic patients measure U&Es and creatine kinase. Perform a 12-lead ECG and monitor cardiac rhythm. Patients who have been unconscious may be hypothermic.

Hypotension, though unlikely, may be controlled with intravenous fluids. In adults, if severe hypotension persists, determine the cause and consider treatment with the following; if hypotension is mainly due to decreased systemic vascular resistance, drugs such as noradrenaline or high dose dopamine may be beneficial, if hypotension is due to reduced cardiac output dobutamine, or in severe cases adrenaline may be beneficial. However it should be noted that hydroxyzine has been shown to inhibit and reverse the vasopressor effect of adrenaline.

Analeptic agents should not be used since they may cause seizures.

As in the management of overdosage with any drug, it should be borne in mind that multiple agents may have been taken.

Shelf life: 24 months.

Do not store above 25°C.

White opaque 250/51 micron PVC/PCTFE (Aclar) - 20 micron aluminium foil blister strips containing 84 × 10mg tablets, (6 blister strips per carton).

No special requirements.