Mitotane Drug Interactions
1. Hepatic Enzyme Induction
Mitotane is a strong hepatic enzyme inducer and may affect drugs metabolized by the liver.
2. Specific Interactions
(1) Oral anticoagulants (e.g., warfarin): accelerated metabolism; close monitoring of coagulation function and dose adjustment required.
(2) Central nervous system depressants: may enhance central depressant effects.
(3) Corticosteroids: accelerated metabolism; increased corticosteroid dosage may be necessary.
3. Interference with Laboratory Tests
(1) Adrenal steroid measurements: decreases urinary 17-hydroxycorticosteroids (17-OHCS) and aldosterone metabolite excretion (plasma cortisol peak concentration and urinary free cortisol are recommended as therapeutic monitoring parameters).
(2) Thyroid function tests: competes for thyroxine-binding globulin, reducing serum protein-bound iodine levels (free thyroxine concentrations are usually normal).
Mitotane Pharmacokinetics
1. Absorption: oral bioavailability approximately 40%; peak plasma concentration reached in 3‑5 hours.
2. Onset: adrenal suppression occurs within 2‑4 weeks.
3. Distribution: extensively distributed throughout the body (fat is the main storage site); small amounts of metabolites may cross into cerebrospinal fluid.
4. Metabolism: primarily converted to metabolites in the liver.
5. Elimination: excreted via urine (10%) and bile (1‑17%).
6. Half‑life: 18‑159 days.
Mitotane Mechanism of Action
Direct cytotoxic effect destroys the adrenal cortex (mainly zona fasciculata and zona reticularis), inhibits cortisol/aldosterone synthesis, and alters peripheral metabolism of steroids.
Mitotane Storage
Store in a light‑resistant, tightly closed container at room temperature.
Important Reminders
1. Dizziness or fatigue may occur during treatment; avoid driving or operating machinery.
2. Inform your doctor immediately if you experience trauma, infection, or illness.
3. Inform your doctor of all medications you are taking or plan to take (including over‑the‑counter products).
4. If you are pregnant or breastfeeding, actively inform your doctor.
