• Monitor patient for changes in signs of Cushing's syndrome (moon face, buffalo hump, hypertension, fragility, hirsutism, mood swings, increased susceptibility to infections) throughout therapy.
• Monitor BP with patient recumbent and upright throughout therapy to detect hypotension resulting from reduced aldosterone levels.
• Assess patient for CNS side effects (clumsiness, dizziness, drowsiness, lack of energy, uncontrolled eye movements). These are dose related and require dose reduction, but usually decrease within 2–6 wk, even with continued therapy. May necessitate discontinuation of therapyGeri: Older patients are more susceptible to CNS effects; assess frequently during therapy and determine risk for falls.
• Assess patient for measles-like rash and fever, which occurs within 10–15 days after start of therapy and lasts 5–7 days. May be treated with diphenhydramine and withholding of dose. After a mild to moderate rash disappears, restart therapy at 250 mg/day and gradually increase to therapeutic dose. Discontinuation of therapy may be required if severe skin rash occurs or if mild to moderate skin rash persists longer than 5–8 days.
• Monitor patient closely during periods of stress (surgery, trauma, acute illness). Additional steroids may be required. Aminoglutethimide should be discontinued after shock or severe trauma.

Lab Test Considerations:

Monitor 8 AM plasma cortisol levels or 24-hr urinary 17-hydroxycorticosteroid concentrations periodically throughout therapy in patients with adrenal disorders to assess clinical response and determine whether mineralocorticoid/corticosteroid supplementation is necessary. Dose may be titrated according to levels that are decreased slowly in patients with adrenal hyperfunction and rapidly with breast cancer patients.

• Monitor serum acid phosphatase concentrations periodically throughout therapy in patients with prostatic carcinoma. Concentrations should decrease in response to therapy.
• Urinary aldosterone concentrations may be decreased, causing orthostatic hypotension and hyponatremia.
• May cause increased serum concentrations of thyroid-stimulating hormone (TSH) as a reflex response to reduced serum thyroxine levels. Monitor thyroid function tests periodically during therapy.
• May cause elevated AST, alkaline phosphatase, and bilirubin concentrations.
• Monitor CBC and serum electrolytes (sodium, potassium, chloride) periodically during therapy. May cause leukopenia, thrombocytopenia, or agranulocytosis.