Mitotane (Specialist drug)

How it works

It selectively damages adrenocortical cells and inhibits steroidogenesis, reducing cortisol production and causing adrenal cytotoxicity.

Prescribing in practice

• It causes adrenal insufficiency, so corticosteroid (glucocorticoid, with mineralocorticoid as needed) replacement is essential and patients require stress-dose cover during illness or surgery.
• Plasma mitotane concentrations are monitored to balance efficacy against neurotoxicity, and it is a potent CYP3A4 inducer that lowers levels of many co-administered drugs.
• Central nervous system and gastrointestinal toxicity are dose-limiting, and it raises hormone-binding globulins which complicates hormone interpretation.

Monitoring

Monitor plasma mitotane concentrations, adrenal and thyroid function, liver function and for neurological toxicity throughout treatment.

Counselling the patient

• Never stop your steroid replacement and carry a steroid alert card; increase the dose and seek help if you are unwell, as advised.
• Report drowsiness, confusion, unsteadiness, nausea or vomiting to your team.
• Tell any prescriber you take mitotane, as it affects how many other medicines work.

Evidence & guidelines

Established as the principal medical therapy for adrenocortical carcinoma per the SPC and specialist endocrine-oncology guidance.