Drug Interactions between abiraterone and Onmel

ADJUST DOSING INTERVAL: Food increases the absorption of itraconazole capsules but decreases the absorption of itraconazole oral solution. Cola beverages may increase the bioavailability of itraconazole capsules. Itraconazole capsules require an acidic gastric pH for adequate dissolution and subsequent absorption. Cola beverages help lower gastric pH and improve absorption.

GENERALLY AVOID: Grapefruit juice may impair the absorption of itraconazole capsules, resulting in decreased antifungal effects. In a small, randomized, crossover study, the administration of itraconazole capsules with double-strength grapefruit juice (compared to water) was associated with significantly decreased (43%) plasma concentrations of itraconazole and its pharmacologically active hydroxy metabolite, as well as delayed times to reach peak concentrations of both. The exact mechanism of interaction is unknown but may involve reduced absorption of itraconazole secondary to enhanced activity of intestinal P-glycoprotein drug efflux pumps and delayed gastric emptying induced by certain compounds present in grapefruits. Another study reported no pharmacokinetic changes with single-strength grapefruit juice. Whether or not these observations apply to itraconazole oral solution is unknown.

MANAGEMENT: The manufacturer recommends that the capsules be taken immediately after a full meal and the solution be taken on an empty stomach to ensure maximal absorption. Cola beverages may help increase the bioavailability of itraconazole capsules, particularly in patients with hypochlorhydria or those treated concomitantly with gastric acid suppressants. Until more information is available, it may be advisable to avoid the consumption of grapefruits and grapefruit juice during itraconazole therapy.

Switch to consumer interaction data

ADJUST DOSING INTERVAL: Food may significantly increase the oral bioavailability of some formulations of abiraterone acetate. Compared to administration in the fasted state, abiraterone peak plasma concentration (Cmax) and systemic exposure (AUC) were approximately 7- and 5-fold higher, respectively, when a single dose of abiraterone acetate was administered with a low-fat meal (7% fat; 300 calories) and approximately 17- and 10-fold higher, respectively, when it was administered with a high-fat meal (57% fat; 825 calories). Given the normal variation in the content and composition of meals, taking abiraterone acetate with meals has the potential to result in increased and highly variable exposures. The safety of these increased exposures during multiple dosing has not been assessed. However, the abiraterone acetate 125 mg tablet, commonly marketed as Yonsa, was found to have an approximately 6.5-fold higher Cmax and 4.4-fold higher AUC when a single dose of 500 mg (4 tablets) was administered with a high-fat meal (56% - 60% fat, 900 - 1000 calories) compared to overnight fasting in healthy volunteers. These differences were not considered clinically significant for this formulation.

MANAGEMENT: Some formulations of abiraterone acetate must be taken on an empty stomach. No food should be consumed for at least two hours before and one hour after the abiraterone acetate dose. However, the abiraterone acetate 125 mg tablet, commonly marketed as Yonsa, can be taken with or without food. The manufacturer's product labeling should be consulted for specific guidance.

Switch to consumer interaction data