Drug Interactions between baloxavir marboxil and Norisodrine with Calcium Iodine

GENERALLY AVOID: Coadministration with foods or medications that contain polyvalent cations such as dairy products, calcium-fortified beverages, certain laxatives, antacids, or oral supplements may decrease the plasma concentrations and therapeutic efficacy of baloxavir. The proposed mechanism is chelation of baloxavir by polyvalent cations, forming a complex that is poorly absorbed from the gastrointestinal tract. A significant decrease in baloxavir exposure was observed in monkeys when the prodrug, baloxavir marboxil, was coadministered with calcium, aluminum, magnesium, or iron. However, clinical data in humans are lacking.

When baloxavir marboxil was administered with food, baloxavir peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 48% and 36%, respectively, relative to administration under fasting. These changes are not considered clinically significant.

MANAGEMENT: Baloxavir marboxil may be taken with or without food. However, coadministration with dairy products, calcium-fortified beverages, or polyvalent cation-containing laxatives, antacids, or oral supplements (e.g., calcium, iron, magnesium, selenium, or zinc) should be avoided.

MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.