Lysodren Side Effects: What to Expect and When to Call Your Doctor

Lysodren (mitotane) is a powerful medication with a significant side effect profile. Because it works by suppressing and ultimately damaging adrenal cortex tissue, its effects extend far beyond the tumor — touching hormonal systems, the nervous system, the liver, and more. Understanding what to expect can help you manage side effects proactively and recognize when something needs urgent attention.

The Most Important Warning: Adrenal Crisis Risk

Before reviewing the full side effect list, the most critical safety fact about Lysodren is this: patients on Lysodren are at increased risk for adrenal crisis during shock, severe trauma, or infection. This is a Boxed Warning in the FDA prescribing information.

Adrenal crisis is a medical emergency. Symptoms include: sudden severe pain in the abdomen, back, or legs; weakness, fatigue, confusion, or loss of consciousness; vomiting and diarrhea; very low blood pressure; and loss of consciousness. If you are on Lysodren and experience a severe illness, injury, or surgery, you must inform your medical team immediately so they can administer hydrocortisone and closely monitor you.

Common Side Effects (Affecting Many Patients)

The following side effects are reported frequently in patients taking Lysodren. They are often dose-dependent and may improve with dose reduction:

Gastrointestinal effects: Nausea, vomiting, diarrhea, abdominal discomfort, and loss of appetite (anorexia) are among the most common side effects, especially when starting treatment or increasing the dose.

Central nervous system effects: Dizziness, lightheadedness, mental sluggishness, depression, and fatigue are commonly reported. These are often worse at higher plasma levels.

Rash: Skin rash occurs in some patients.

Elevated cholesterol and triglycerides: Lysodren can raise blood lipid levels, which your doctor will monitor.

Decreased thyroid hormones: Lysodren can cause hypothyroidism. Regular thyroid function tests are part of monitoring.

Decreased testosterone (in men): Men may experience low testosterone, with associated symptoms like fatigue, reduced libido, and mood changes.

Serious Side Effects: Call Your Doctor Immediately

The following side effects require immediate medical attention:

Signs of adrenal insufficiency or adrenal crisis: Profound weakness, sudden severe pain, vomiting, low blood pressure, confusion, or loss of consciousness — especially during illness, surgery, or injury

Severe CNS toxicity: Significant sedation, confusion, memory loss, vertigo, or difficulty with coordination — these can indicate mitotane plasma levels above 20 mg/L

Liver problems: Yellowing of the skin or eyes (jaundice), dark urine, or severe abdominal pain in the upper right area

Blood disorders: Unusual bleeding or bruising, or signs of prolonged bleeding after a cut (Lysodren can prolong bleeding time)

Vision changes: Blurry vision or other eye changes

Rapid unexplained weight loss

Side Effects Related to High Plasma Levels (Above 20 mg/L)

Lysodren requires blood level monitoring to ensure plasma concentrations stay within the therapeutic range of 14–20 mg/L. When levels rise above 20 mg/L — which can happen even with a constant dose, because the drug accumulates in fat tissue — severe neurotoxicity can occur, including:

Sedation and excessive sleepiness

Lethargy and extreme fatigue

Vertigo and balance problems

Cognitive impairment (memory problems, confusion, slowed thinking)

Long-term high-dose Lysodren may also cause brain damage. This is why plasma level monitoring is not optional — it is a critical safety tool. If any of these symptoms develop, contact your oncologist immediately.

Special Concerns for Specific Populations

Pregnancy: Lysodren can cause fetal harm, including preterm birth and early pregnancy loss. Women of reproductive potential must use effective non-hormonal contraception during treatment and until plasma levels are undetectable.

Breastfeeding: Do not breastfeed while on Lysodren.

Children: Safety and effectiveness in pediatric patients have not been established. Case reports suggest risks of neuro-psychological effects, growth delays, and hormonal changes in children.

Driving and operating machinery: CNS side effects like dizziness and sedation may impair your ability to drive. Discuss with your doctor when and if it is safe to drive.

Managing Side Effects: Practical Tips

Take Lysodren with food: High-fat meals enhance absorption and may reduce GI side effects.

Be consistent with timing: Take doses at the same time relative to meals every day.

Keep all monitoring appointments: Blood level checks every 2 weeks during titration are essential for catching toxicity early.

Carry emergency hydrocortisone: Your doctor should prescribe an emergency hydrocortisone injection kit and teach you (and a caregiver) when and how to use it.

See also: Lysodren Drug Interactions: What to Avoid and What to Tell Your Doctor.

If you're having trouble filling your Lysodren prescription, medfinder can help you find a specialty pharmacy near you that carries it.