procyclidine hydrochloride: clinical use

Prescribing considerations

• Confirm that symptoms are parkinsonian or acute extrapyramidal effects; procyclidine may worsen tardive dyskinesia.
• Review continuing need for treatment of neuroleptic-induced symptoms and avoid abrupt withdrawal.
• Older people are particularly susceptible to confusion, cognitive impairment, memory disturbance, disorientation and hallucinations.
• Use caution with renal or hepatic impairment because detailed evidence is lacking and the medicine undergoes hepatic metabolism with urinary elimination.
• Consider misuse potential when prescribing and reviewing treatment.
• Procyclidine injection has been discontinued from the UK market; current selected products are oral.

Contraindications and cautions

• Hypersensitivity to procyclidine or product excipients
• Untreated urinary retention
• Closed-angle glaucoma
• Gastrointestinal obstruction

Monitoring

• Therapeutic response and continuing indication
• Urinary retention, constipation, visual symptoms and dry mouth
• Cognition, memory, confusion, hallucinations and psychotic symptoms, especially in older people
• Tardive dyskinesia or worsening abnormal movements
• Heart rate and cardiovascular adverse effects where clinically relevant
• Adherence, abrupt-withdrawal risk and possible misuse

Clinical pharmacology

A centrally acting synthetic antimuscarinic that blocks excitatory acetylcholine effects at muscarinic receptors. Oral absorption is adequate; metabolism is principally hepatic and elimination is partly urinary.

Formulation and product differences

• Selected products include tablets and two differently concentrated oral solutions; verify the exact product before measuring or switching.
• The selected tablet contains lactose.
• Both selected oral solutions contain maltitol, parabens and propylene glycol; the less concentrated solution also lists benzyl alcohol and a small quantity of ethanol.
• Parabens may cause delayed allergic reactions, and maltitol-containing products are unsuitable for people with hereditary fructose intolerance.

Oral solution

Route: Oral

Strengths: 2.5 mg/5 mL, 5 mg/5 mL

Tablet

Route: Oral

Strengths: 5 mg