Drug Interaction Report

MONITOR CLOSELY: Coadministration of capmatinib with strong CYP450 3A4 inhibitors may increase the risk and severity of capmatinib adverse effects, such as interstitial lung disease, pneumonitis, and hepatotoxicity. The proposed mechanism is decreased clearance due to inhibition of CYP450 3A4, which is one of the primary enzymes responsible for the metabolic clearance of capmatinib. Coadministration with itraconazole (a strong CYP450 3A4 inhibitor) increased the systemic exposure (AUC) of capmatinib by 42%, but did not affect the peak plasma concentration (Cmax) of capmatinib.

MANAGEMENT: Close monitoring is recommended whenever capmatinib is used with a strong CYP450 3A4 inhibitor. Clinical and laboratory monitoring should be considered whenever a strong CYP450 3A4 inhibitor is added to or withdrawn from therapy with capmatinib, and the dosage adjusted as necessary based on clinical response and toxicity. Patients should be monitored for the development of adverse effects.

Although some in vitro data indicate synergism between macrolide antibiotics and penicillins, other in vitro data indicate antagonism. When these drugs are given together, neither has predictable therapeutic efficacy. Data are available for erythromycin, although theoretically this interaction could occur with any macrolide. Except for monitoring of the effectiveness of antibiotic therapy, no special precautions appear to be necessary.

Grapefruit juice may delay the gastrointestinal absorption of clarithromycin but does not appear to affect the overall extent of absorption or inhibit the metabolism of clarithromycin. The mechanism of interaction is unknown but may be related to competition for intestinal CYP450 3A4 and/or absorptive sites. In an open-label, randomized, crossover study consisting of 12 healthy subjects, coadministration with grapefruit juice increased the time to reach peak plasma concentration (Tmax) of both clarithromycin and 14-hydroxyclarithromycin (the active metabolite) by 80% and 104%, respectively, compared to water. Other pharmacokinetic parameters were not significantly altered. This interaction is unlikely to be of clinical significance.