PROCHLORPERAZINE-WGR

What it is

Prochlorperazine-WGR is a medicine containing prochlorperazine maleate 5 mg per tablet. Prochlorperazine is a phenothiazine with a piperazine moiety in the side chain that possesses strong antiemetic activity with less sedative action than chlorpromazine.

Approved indications

— Treatment of nausea associated with migraine

Dosing overview

For adults 18 years of age and over, the recommended dosage is 5 or 10 mg two or three times daily as necessary. For acute treatment, 20 mg at once, followed, if necessary, by 10 mg two hours later. In elderly patients, dosages in the lower range are generally sufficient and dosage should be increased more gradually.

Key safety warnings

Migraine should be medically diagnosed prior to first use of this product. A potentially fatal syndrome called neuroleptic malignant syndrome has been reported in association with antipsychotic drugs, characterised by muscular rigidity, fever, hyperthermia, altered consciousness and autonomic instability. Very rare cases of QT interval prolongation have been reported with prochlorperazine, and neuroleptic phenothiazines may potentiate QT interval prolongation which increases the risk of serious ventricular arrhythmias of the torsade de pointes type, which is potentially fatal. Tardive dyskinesia may develop in patients on antipsychotic drugs, and both the risk of developing the syndrome and the likelihood that it will become irreversible are believed to increase as the duration of treatment and the total cumulative dose of the drug increases. Prochlorperazine can cause photosensitisation, therefore patients should be advised to avoid exposure to direct sunlight during treatment. Cases of venous thromboembolism, sometimes fatal, have been reported with antipsychotic drugs, and all possible risk factors for VTE should be identified before and during treatment with prochlorperazine. Patients should be warned about drowsiness and advised not to drive or operate machinery, particularly during the early days of treatment, as prochlorperazine may impair mental and physical activity, especially during the first few days of therapy.

Contraindications

Contraindications include circulatory collapse, central nervous system depression (coma or drug intoxication with alcohol, barbiturates, narcotics etc), previous history of a hypersensitivity reaction to phenothiazines especially to prochlorperazine, and bone marrow depression. The medicine should not be used in children due to a possible association between use of phenothiazine-containing products and Sudden Infant Death Syndrome (SIDS). Do not use in children and adolescents under 18 years of age.

PBS listing

The 5 mg tablet is listed on the PBS with 2 items, restriction type unrestricted, with an ex-manufacturer price of A$2.50.

Regulatory history

Prochlorperazine-WGR (ARTG 172128) was first listed on 12 January 2011.