MITOTANE
| MITOTANE (mye'toe-tane) Lysodren Classifications: antineoplastic; Therapeutic: antineoplastic Pregnancy Category: C |
Availability
500 mg tablets
Action
Cytotoxic agent with suppressant action on the adrenal cortex. Modifies peripheral metabolism of steroids and reduces production of adrenal steroids. Extra-adrenal metabolism of cortisol is altered, leading to reduction in 17-hydroxycorticosteroids (17-OHCS); however, plasma levels of corticosteroids do not fall.
Therapeutic Effect
Cytotoxic agent with suppressant action on the adrenal cortex.
Uses
Inoperable adrenal cortical carcinoma (functional and nonfunctional).
Unlabeled Uses
Cushing's syndrome secondary to pituitary disorders.
Contraindications
Pregnancy (category C), lactation; children.
Cautious Use
Liver disease.
Route & Dosage
| Adrenocortical Carcinoma Adult: PO 9–10 g/d in divided doses t.i.d. or q.i.d. (tolerated doses range: 2–16 g/d) |
Administration
Oral- Withhold temporarily and consult physician if emergency occurs, since adrenal suppression is its prime action. Exogenous steroids may be required until the already depressed adrenal starts secreting steroids.
- Store at 15°–30° C (59°–86° F) in tight, light-resistant containers.
Adverse Effects (≥1%)
CNS: Vertigo, dizziness, drowsiness, tiredness, depression, lethargy, sedation, headache, confusion, tremors. CV: Hypertension, hypotension, flushing GI: Anorexia, nausea, vomiting, diarrhea. Urogenital: Hematuria, hemorrhagic cystitis, albuminuria. Endocrine: Adrenocortical insufficiency. Special Senses: Blurred vision, diplopia, lens opacity, toxic retinopathy. Body as a Whole: Generalized aching, fever, muscle twitching, hypersensitivity reactions, hyperpyrexia. Skin: Rash, cutaneous eruptions and pigmentation. Metabolic: Hypouricemia, hypercholesterolemia.Diagnostic Test Interference
Mitotane decreases protein-bound iodine (PBI) and urinary 17-OHCS levels.
Interactions
Drug: Potentiates sedative effects of alcohol and other cns depressants; may increase the metabolism of phenytoin, phenobarbital, warfarin, decreasing their effectiveness.Pharmacokinetics
Absorption: Approximately 40% absorbed from GI tract. Onset: 2–4 wk. Peak: 3–5 h. Distribution: Deposits in most body tissues, especially adipose tissue. Metabolism: In liver. Elimination: Small amount excreted in bile. Half-Life: 18–159 d.Nursing Implications
Assessment & Drug Effects
- Monitor pulse and BP for early signs of shock (adrenal insufficiency).
- Observe for symptoms of hepatotoxicity (see Appendix F). Report them promptly, since reduced hepatic capacity can increase toxicity of mitotane and because dose may have to be decreased.
- Notify physician if following persist and become more severe: Aching muscles, fever, flushing, and muscle twitching.
- Monitor obese patient for symptoms of adrenal hypofunction. Because a large portion of the drug deposits in fatty tissue, the obese are particularly susceptible to prolonged adverse effects.
- Make neurological and behavioral assessments at regular intervals throughout therapy.
Patient & Family Education
- Be aware that mitotane does not cure but does reduce tumor mass, pain, weakness, anorexia, and steroid symptoms.
- Report symptoms of adrenal insufficiency (weakness, fatigue, orthostatic hypotension, pigmentation, weight loss, dehydration, anorexia, nausea, vomiting, and diarrhea) to physician.
- Exercise caution when driving or performing potentially hazardous tasks requiring alertness because of drug-induced drowsiness, tiredness, dizziness. Symptoms tend to recede with continuation in therapy.
- Use contraceptive measures during therapy because of teratogenic properties of drug. Notify physician if you suspect you are pregnant.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug