Etoposide (Specialist drug)

How it works

It inhibits topoisomerase II, stabilising the enzyme-DNA complex and causing DNA strand breaks that prevent re-ligation, leading to cell-cycle arrest and apoptosis.

Prescribing in practice

• Severe, dose-limiting myelosuppression occurs, so a full blood count must be checked before each course and treatment withheld for significant cytopenias.
• Administer only under specialist oncology supervision; intravenous infusion must be given slowly to avoid hypotension and infusion reactions.
• There is a recognised risk of secondary acute leukaemia, and dose adjustment is needed in hepatic and renal impairment.

Monitoring

Monitor full blood count before and during each cycle, together with renal and hepatic function.

Counselling the patient

• Report fever or signs of infection urgently because of the risk of low blood counts.
• Hair loss is common and usually reversible after treatment ends.
• Effective contraception is advised during and after treatment.

Evidence & guidelines

Etoposide is an established component of evidence-based combination regimens, including for small-cell lung and testicular cancers, supported by long-standing trial data.