Mitotane (Lysodren): Uses, Dosing, Cortisol Replacement, and What to Expect

What Mitotane Is Approved to Treat

Mitotane directly suppresses and damages adrenal-cortex tissue. The current U.S. prescribing information indicates Lysodren for functional or nonfunctional ACC that cannot be removed surgically [1].

That labeled indication is narrower than all of the ways mitotane is used in expert oncology practice:

• Unresectable, recurrent, or metastatic ACC: mitotane may be used alone or with systemic chemotherapy, depending on disease burden and the patient's condition.
• Hormone-producing ACC: its delayed adrenal-suppressive effect may help control excess steroid production, although faster steroidogenesis inhibitors are often needed initially.
• After complete surgery: adjuvant mitotane is a guideline-based decision rather than the FDA-labeled indication. The ESE-ENSAT guideline favors discussion in patients at high recurrence risk, such as stage III disease, a microscopically positive margin, or Ki-67 above 10% [2].

ACC care should be coordinated through an experienced endocrine-oncology team. Mitotane has slow and variable pharmacokinetics, a narrow therapeutic window, and interactions that can change the effect of many other drugs.

What the ADIUVO Trial Changed

Older retrospective evidence associated adjuvant mitotane with longer recurrence-free survival after complete resection, but those comparisons were vulnerable to selection bias [3].

The randomized ADIUVO trial is no longer “ongoing.” Results were published in 2023. It enrolled 91 patients with completely resected, low- to intermediate-risk ACC (stage I to III, R0 resection, and Ki-67 no higher than 10%). Five-year recurrence-free survival was 79% with mitotane and 75% with surveillance; the difference was not statistically conclusive. Every participant who received mitotane reported an adverse event, and 19% discontinued it [4].

ADIUVO was stopped early because of slow enrollment and cannot exclude a small benefit. Its practical message is narrower: routine adjuvant mitotane is difficult to justify for every low-risk patient. It does not settle treatment for high-risk disease, where guidelines still support individualized adjuvant treatment.

Dosing and Blood-Level Monitoring

The current label recommends an initial total dose of 2,000 to 6,000 mg per day in three or four divided doses. Tablets should be swallowed whole, taken with food, and handled as a hazardous drug; caregivers should wear disposable gloves [1].

The dose is then adjusted according to tolerability, clinical response, and measured mitotane concentration. The labeled target is 14 to 20 mg/L, usually reached after 3 to 5 months. The label suggests checking levels about every two weeks after starting and after dose changes, then periodically once stable [1].

Mitotane accumulates in fat and can continue entering the bloodstream after the dose is reduced or stopped. Its terminal half-life after discontinuation ranges from 18 to 159 days. A stable dose can therefore produce a delayed rise in concentration, especially with weight loss. Severe neurologic toxicity becomes more common above 20 mg/L [1].

No online dose schedule can safely substitute for serial blood levels and adverse-effect assessment.

Adrenal Insufficiency and Cortisol Replacement

Mitotane can cause or worsen adrenal insufficiency. Symptoms such as severe weakness, vomiting, dizziness, low blood pressure, confusion, or collapse require urgent assessment because adrenal crisis can be fatal [1].

The ESE-ENSAT guideline recommends glucocorticoid replacement for patients receiving mitotane unless clinically important cortisol excess is still present. Hydrocortisone or cortisone acetate is generally preferred. Mitotane strongly induces CYP3A4 and increases cortisol-binding globulin, so patients often need at least twice the usual physiologic replacement exposure [2]. A metabolic study found that CYP3A4 induction rapidly inactivated more than half of administered hydrocortisone, explaining why individualized higher replacement can be necessary [5].

Replacement adequacy cannot be judged from a single total serum cortisol value because mitotane changes steroid metabolism and binding proteins. Clinical status, ACTH, electrolytes, renin when relevant, and the specialist's treatment plan all matter.

During shock, major trauma, serious infection, surgery, or established adrenal insufficiency, the label directs clinicians to withhold mitotane temporarily and manage the adrenal-risk state [1].

Monitoring Beyond the Mitotane Level

Specialist monitoring commonly includes:

• neurologic and behavioral assessment;
• liver enzymes and bilirubin;
• complete blood count;
• thyroid function, especially if cognitive symptoms appear;
• lipids;
• ACTH and clinical markers of glucocorticoid replacement;
• renin, potassium, and blood pressure when mineralocorticoid deficiency is possible;
• testosterone and sex-hormone binding globulin when symptomatic hypogonadism is suspected.

The ESE-ENSAT guideline recommends frequent review early in therapy, often every 3 to 4 weeks, because GI toxicity, adrenal insufficiency, neurologic symptoms, and liver abnormalities may emerge while levels are rising [2].

Drug Interactions

Mitotane is a strong and persistent inducer of CYP3A4. It can reduce exposure to many CYP3A substrates, including some anticoagulants, anticonvulsants, sedatives, immunosuppressants, steroid hormones, and cancer therapies. The interaction can persist after mitotane is discontinued because measurable drug remains in the body [1, 2].

Hormonal contraceptives may be less effective. The current label advises effective nonhormonal contraception during treatment and after discontinuation for as long as mitotane levels remain detectable. It does not specify a universal five-year duration [1].

Patients should have their complete prescription, over-the-counter, and supplement list reviewed by the treating oncology-pharmacy team before starting or changing another medicine.

Pregnancy, Breastfeeding, and Handling

Mitotane can cause fetal harm. Pregnancy status should be checked before treatment when relevant, and nonhormonal contraception should continue while drug levels remain detectable. Breastfeeding is also not advised during treatment or while detectable mitotane persists [1].

Lysodren is a hazardous drug. Tablets should not be crushed, chewed, or split. Caregivers should wear disposable gloves when handling them and wash exposed skin promptly if a damaged tablet is contacted [1].

Mitotane With Chemotherapy

For advanced ACC, the FIRM-ACT randomized trial compared etoposide, doxorubicin, and cisplatin plus mitotane (EDP-M) with streptozocin plus mitotane. EDP-M improved objective response and progression-free survival, but the overall-survival difference did not reach statistical significance [6]. That regimen is intensive and belongs in an expert oncology setting.