Drug Interactions between abiraterone and Duzallo

ADJUST DOSING INTERVAL: The tolerability of allopurinol may be improved by giving it after a meal. Additionally, when the dose is greater than 300 mg, dividing the total daily dose into smaller doses administered more often may be appropriate to help minimize gastrointestinal irritation.

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

MANAGEMENT: To improve tolerability, some manufacturers suggest administering allopurinol after a meal. Additionally, if the daily dose is greater than 300 mg, administering allopurinol in divided doses may help reduce gastrointestinal intolerance. Patients should also be counseled 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 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.