Drug Interaction Report

GENERALLY AVOID: Drugs that directly affect the pituitary secretion of growth hormone (e.g., somatostatin, insulin, glucocorticoids, cyclooxygenase inhibitors such as aspirin and nonsteroidal anti-inflammatory drugs) and drugs that may transiently elevate growth hormone levels (e.g., clonidine, levodopa, insulin) may impact the accuracy of the macimorelin diagnostic test.

MANAGEMENT: Concomitant use of macimorelin with drugs affecting growth hormone levels should generally be avoided. A sufficient washout period following discontinuation of these drugs is recommended prior to macimorelin administration.

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations and systemic effects of orally administered budesonide. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. According to the manufacturer, the systemic exposure of oral budesonide approximately doubles after extensive intake of grapefruit juice.

MANAGEMENT: Patients receiving budesonide should avoid the regular consumption of grapefruits and grapefruit juice to prevent undue increases in plasma budesonide levels and systemic effects.

ADJUST DOSING INTERVAL: Food reduces the oral bioavailability of macimorelin. According to the product labeling, administration with a liquid meal decreased macimorelin peak plasma concentration (Cmax) and systemic exposure (AUC) by 55% and 49%, respectively, compared to administration under fasting conditions (i.e., for at least 8 hours).

MANAGEMENT: Macimorelin should be administered after fasting for at least 8 hours.