Drug Interactions between brigatinib and mitotane

ADJUST DOSING INTERVAL: Fat-rich food enhances the absorption of mitotane. One study evaluated blood levels of mitotane (o,p'-DDD) after subjects ingested a single dose of 2 g administered using various delivery vehicles (e.g., tablets, granules, milk, chocolate or oil emulsion). Mitotane plasma levels were significantly higher for milk, chocolate, and oil emulsion when compared to those who received tablets or granules alone. In the same study, mitotane levels were evaluated in subjects following long-term treatment (total dose of 200 g over 30 to 60 days) in tablet, oil emulsion, or milk formulations. Significantly higher mean plasma levels were recorded in subjects who received mitotane as an oil emulsion or mixed in milk, when compared to tablets alone. Additionally, the recovery of o,p'-DDD from the feces was about 5 times higher in subjects who received tablets alone, suggesting absorption was reduced when compared to subjects who received mitotane mixed with a fat-rich vehicle (e.g., oil emulsion or milk).

GENERALLY AVOID: Concomitant use of mitotane with central nervous system (CNS) depressants, including alcohol, may potentiate adverse effects such as somnolence and sedation.

MANAGEMENT: According to product labeling, mitotane tablets should be taken during meals containing fat-rich food (e.g., milk, chocolate, or oil) and with a full glass of water. Patients should be advised to avoid or limit consumption of alcohol and to avoid activities requiring mental alertness such as driving or operating hazardous machinery until they know how the medication affects them.

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of brigatinib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Itraconazole, a potent CYP450 3A4 inhibitor, has been shown to double brigatinib systemic exposure (AUC) in healthy volunteers. Increased exposure to brigatinib may increase the risk of adverse effects such as nausea, vomiting, diarrhea, hypertension, bradycardia, hyperglycemia, visual disturbances, lymphopenia, anemia, and elevations in pancreatic enzymes and creatine phosphokinase.

Food does not significantly affect the oral bioavailability of brigatinib. When brigatinib was administered to healthy volunteers after a high-fat meal (920 calories; 59 g fat, 58 g carbohydrates, 40 g proteins), brigatinib peak plasma concentration (Cmax) decreased by 13% and systemic exposure (AUC) did not change compared to administration after overnight fasting.

MANAGEMENT: Brigatinib may be taken with or without food. Patients should avoid consumption of grapefruit and grapefruit juice during treatment with brigatinib.