Increased plasma conc w/ strong CYP3A &/or P-gp inhibitors eg, ketoconazole, itraconazole, voriconazole, ritonavir, saquinavir, telithromycin, posaconazole, nefazodone. Decreased plasma conc w/ strong CYP3A4 inducers eg, carbamazepine, phenobarb, phenytoin, rifabutin, rifampicin, St. John's wort (
Hypericum perforatum). Increased plasma conc of sensitive CYP2C8 substrates (eg, odiaquine, cerivastatin, enzalutamide, paclitaxel, repaglinide, torasemide, sorafenib, rosiglitazone, buprenorphine, selexipag, dasabuvir, montelukast); sensitive CYP3A4 substrates (eg, alfentanil, avanafil, buspirone, conivaptan, darifenacin, darunavir, ebastine, lomitapide, lovastatin, midazolam, naloxegol, nisoldipine, saquinavir, simvastatin, tipranavir, triazolam, vardenafil); sensitive P-gp substrates (eg, fexofenadine, dabigatran etexilate, colchicine, saxagliptin) & particularly those w/ narrow therapeutic index (eg, digoxin). Decreased AUC
0-INF & C
max w/ multiple daily doses of omeprazole when selpercatinib was administered fasting.
In vivo interactions w/ clinically relevant MATE1 substrates (eg, creatinine) may occur. Insufficient response to levothyroxine substitution.