Drug Interactions between mifepristone and zuranolone

ADJUST DOSING INTERVAL: Food may significantly increase the plasma concentrations of mifepristone.

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of mifepristone. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Because pharmacokinetic interactions involving grapefruit juice are often subject to a high degree of interpatient variability, the extent to which a given patient may be affected is difficult to predict.

MANAGEMENT: When mifepristone is used daily to control hyperglycemia secondary to hypercortisolism in patients with endogenous Cushing's syndrome, it should be taken with food to achieve consistent plasma drug levels. Patients should be advised to avoid consuming grapefruit or grapefruit juice during treatment with mifepristone, as it may cause increased adverse effects such as headache, dizziness, fatigue, nausea, vomiting, cramping, diarrhea, hypokalemia, adrenal insufficiency, vaginal bleeding, arthralgia, peripheral edema, and hypertension. Because mifepristone is eliminated slowly from the body, the interaction with grapefruit juice may be observed for a prolonged period.

ADJUST DOSING INTERVAL: Food enhances the oral bioavailability of zuranolone. When administered with a low-fat meal (e.g., 400 to 500 calories, 25% fat), zuranolone peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 3.5- and 1.8-fold, respectively, compared to administration under fasted conditions. Zuranolone was administered with food in the premarketing study population. The efficacy of zuranolone when administered in the fasted state is unknown.

GENERALLY AVOID: Concomitant use of zuranolone with central nervous system (CNS) depressants, including alcohol, may potentiate adverse effects such as somnolence, confusion, dizziness, and gait disturbance.

MANAGEMENT: Zuranolone must be administered with fat-containing food (e.g., 400 to 1,000 calories, 25% to 50% fat) according to the manufacturer. Patients should also be advised to avoid or limit consumption of alcohol and to avoid activities requiring mental alertness such as driving or operating hazardous machinery until at least 12 hours after administration of zuranolone.