Drug Interactions between cannabidiol 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.

ADJUST DOSING INTERVAL: Food may affect the plasma concentrations of cannabidiol. In healthy volunteers, administration of cannabidiol with a high-fat/high-calorie meal increased cannabidiol peak plasma concentration (Cmax) by 5-fold and systemic exposure (AUC) by 4-fold and reduced the total variability compared with administration in the fasted state.

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of cannabidiol. The proposed mechanism is inhibition of CYP450 3A4-mediated metabolism of cannabidiol by certain compounds present in grapefruit. The interaction has not been studied, but the product labeling for cannabidiol recommends consideration of a dosage reduction when used with strong or moderate inhibitors of CYP450 3A4. 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.

MANAGEMENT: Cannabidiol should be taken about the same time each day consistently either with or without food. Patients should limit the consumption of grapefruit and grapefruit juice. If they are coadministered, cannabidiol levels should be monitored and the dosage adjusted as necessary.