procarbazine hydrochloride: clinical use

Prescribing considerations

• Initiate and supervise treatment through an experienced oncology service with facilities for clinical and haematological monitoring.
• Review hepatic and renal function, cardiovascular or cerebrovascular disease, phaeochromocytoma, epilepsy and previous marrow-suppressive treatment.
• Discuss potentially irreversible effects on fertility and preservation options before treatment where feasible.
• Review interacting medicines, alcohol intake, vaccination plans and anaesthetic exposure.

Contraindications and cautions

• Hypersensitivity to procarbazine or an excipient
• Pre-existing severe leucopenia or thrombocytopenia
• Severe hepatic or renal damage
• Use for non-malignant disease
• First trimester of pregnancy
• Breastfeeding

Monitoring

• Full blood count before and during treatment, with action for clinically important marrow suppression
• Renal and hepatic function
• Infection, bleeding, allergic skin reactions and hypersensitivity
• New respiratory symptoms suggesting pneumonitis
• Neurological or excessive sedative effects

Clinical pharmacology

Procarbazine is a methylhydrazine cytostatic agent with weak monoamine-oxidase-inhibiting properties. It is readily absorbed orally, distributes rapidly into cerebrospinal fluid and undergoes extensive metabolism to azo and other metabolites before mainly urinary elimination.

Formulation and product differences

• The selected product is a white opaque oral capsule marked “CL50”.
• The capsule contains gelatin and includes mannitol, maize starch, talc and magnesium stearate; excipients should be checked when clinically relevant.
• Undamaged capsules should remain intact, and direct handling should be minimised using local cytotoxic-handling procedures.

Capsule

Route: Oral

Strengths: 50 mg