Pericyazine

How it works

It antagonises central dopamine D2 receptors, which underlies its antipsychotic effect; marked antagonism at muscarinic, histamine H1 and alpha-adrenergic receptors accounts for its sedative and autonomic effects.

Prescribing in practice

• Pronounced sedation and postural hypotension can occur, particularly in elderly or debilitated patients, who are also at increased risk of extrapyramidal effects and falls.
• Like other antipsychotics it carries a risk of QT-interval prolongation and of neuroleptic malignant syndrome.
• Marked antimuscarinic activity may cause dry mouth, blurred vision, constipation and urinary retention, and it should be used with caution in cardiovascular disease and epilepsy.

Monitoring

Monitor for extrapyramidal symptoms, sedation, postural blood pressure and emergent features of neuroleptic malignant syndrome, with metabolic and ECG review where indicated.

Counselling the patient

• This medicine can make you drowsy, so avoid driving or operating machinery until you know how it affects you.
• Stand up slowly to reduce dizziness, and report any high fever, muscle stiffness or confusion urgently.
• Avoid alcohol while taking this medicine as it adds to drowsiness.

Evidence & guidelines

Use of first-generation antipsychotics such as pericyazine is informed by long-standing clinical experience and NICE guidance on antipsychotic prescribing.