etoposide: clinical use

Prescribing considerations

• Use only under an experienced anticancer specialist.
• Assess marrow reserve, current infection, previous chemotherapy or radiotherapy, renal and hepatic function, and serum albumin.
• Oral exposure varies substantially within and between patients.
• Assess tumour lysis risk, particularly with bulky treatment-sensitive disease or renal impairment.
• Discuss contraception, fertility preservation and potential secondary malignancy.

Contraindications and cautions

• Hypersensitivity to etoposide, the parahydroxybenzoate preservatives or another excipient.
• Yellow fever or other live vaccines in immunosuppressed patients.
• Breastfeeding.

Monitoring

• Full blood count and differential during and after treatment.
• Renal and hepatic function, with clinical review for accumulation or toxicity.
• Infection, bleeding, mucositis and gastrointestinal toxicity.
• Signs and biochemical features of tumour lysis syndrome in at-risk patients.
• Treatment response and adverse effects before further therapy.

Clinical pharmacology

Etoposide inhibits topoisomerase II and produces double-strand DNA breaks, with greatest cellular activity in late S and early G2 phases. It is highly protein-bound; oral bioavailability and exposure are variable, and reduced renal clearance or low albumin can increase toxicity risk.

Formulation and product differences

• The selected product is a soft oral capsule taken on an empty stomach.
• Oral exposure is more variable than intravenous exposure, so formulations are not directly interchangeable on a milligram-for-milligram basis.
• Capsules contain parahydroxybenzoate preservatives that can cause immediate or delayed allergic reactions.
• Leaking capsules require cytotoxic-handling precautions and should not be used.

Capsule

Route: Oral

Strengths: 50 mg, 100 mg