etoposide phosphate: clinical use

Prescribing considerations

• Use only under clinicians experienced in systemic anticancer therapy.
• Assess marrow reserve, active infection, renal function, serum albumin, previous chemotherapy or radiotherapy and interacting medicines.
• Renal impairment reduces clearance; individual treatment planning should reflect renal function and toxicity.
• Consider tumour-lysis precautions in patients with bulky, treatment-sensitive disease or renal insufficiency.
• Discuss contraception, reproductive risk and fertility preservation before treatment where relevant.

Contraindications and cautions

• Hypersensitivity to etoposide phosphate or an excipient.
• Yellow fever or other live vaccines in immunosuppressed patients.
• Breastfeeding.

Monitoring

• Full blood count with differential and platelets before treatment and throughout therapy.
• Renal function, liver biochemistry and serum albumin as clinically appropriate.
• Infection, bleeding, mucositis and other treatment-limiting toxicity.
• Blood pressure, infusion site and hypersensitivity symptoms during administration.
• Biochemical and clinical features of tumour lysis in at-risk patients.

Clinical pharmacology

Etoposide phosphate is dephosphorylated in vivo to etoposide. Etoposide disrupts the topoisomerase II–DNA complex, causing double-strand DNA breaks and cell-cycle arrest, particularly in late S and early G2 phases. It is highly protein bound, and clearance involves renal and non-renal pathways.

Formulation and product differences

• The selected product is an intravenous powder requiring aseptic reconstitution; it is not an oral capsule.
• The reconstituted solution may be further diluted with compatible glucose or sodium chloride infusion fluid.
• The vial is single-use and the solution should not be physically mixed with another medicine.
• The formulation contains dextran 40 and sodium citrate and is considered essentially sodium-free.