Drug Interaction Report

Coadministration with osimertinib may alter the plasma concentrations of drugs that are primarily metabolized by CYP450 3A4. In vitro, osimertinib has been shown to be a competitive inhibitor as well as inducer of CYP450 3A4. However, a clinically significant inhibitory effect on CYP450 3A4 has not been demonstrated in clinical drug interaction studies. In a pharmacokinetic study of 49 patients with non-small cell lung cancer, coadministration of osimertinib with the sensitive CYP450 3A4 substrate simvastatin decreased the area under the concentration-time curve (AUC) and peak plasma concentration (Cmax) of simvastatin by approximately 9% and 23%, respectively. These reductions are also not considered clinically significant. Based on these observations, osimertinib may be administered with CYP450 3A4 substrates without the need for increased clinical monitoring.

ADJUST DOSING INTERVAL: Food does not appear to substantially alter the pharmacokinetics of tipranavir. When tipranavir capsules or oral solution was coadministered with ritonavir capsules at steady-state, no clinically significant changes in tipranavir peak plasma concentration (Cmax) and systemic exposure (AUC) were observed under fed conditions (500 to 682 kcal, 23% to 25% calories from fat) relative to fasted conditions. The effect of food on tipranavir exposure during coadministration with ritonavir tablets has not been evaluated. High-fat foods may enhance the gastrointestinal absorption of tipranavir. In a multiple-dose study, administration of tipranavir capsules with a high-fat meal (868 kcal, 53% from fat, 31% from carbohydrates) increased the oral bioavailability of tipranavir by 31% compared to administration with toast and skimmed milk, but did not significantly affect tipranavir Cmax. Thus, tipranavir may be safely taken with standard or high-fat meals.

MANAGEMENT: Tipranavir coadministered with low-dose ritonavir should be taken with food to improve the gastrointestinal tolerability of ritonavir. According to the product labeling, tipranavir coadministered with ritonavir capsules or solution can be taken with or without meals, whereas tipranavir coadministered with ritonavir tablets must be taken with meals.