prochlorperazine mesilate: clinical use

Prescribing considerations

• Assess QT-prolongation risks, including cardiac disease, bradycardia, electrolyte abnormalities and interacting medicines.
• Older, dehydrated or volume-depleted patients are more susceptible to postural hypotension after intramuscular administration.
• Assess venous thromboembolism and stroke risk factors.

Contraindications and cautions

• Hypersensitivity to prochlorperazine, another phenothiazine or an injection excipient.
• The selected intramuscular injection is contraindicated in children.
• Avoid the selected product in liver or renal dysfunction, Parkinson's disease, hypothyroidism, cardiac failure, phaeochromocytoma, myasthenia gravis, prostatic hypertrophy, narrow-angle glaucoma or previous agranulocytosis.

Monitoring

• Regular full blood counts are recommended; investigate unexplained fever or infection immediately.
• Consider ECG and electrolytes where QT risk factors exist.
• Monitor for extrapyramidal effects, neuroleptic malignant syndrome, postural hypotension and tardive dyskinesia.

Clinical pharmacology

A piperazine phenothiazine neuroleptic with dopamine-antagonist antiemetic and antipsychotic actions. Phenothiazine metabolism and elimination may be slower in older people.

Formulation and product differences

• The selected product is a colourless solution intended only for deep intramuscular injection.
• It contains sulphite and metabisulphite excipients.
• Oral standard and buccal tablets have different administration requirements and are not interchangeable with injection instructions.

Injection

Route: Parenteral

Strengths: 12.5 mg/mL