selpercatinib + omeprazole

Combination of **selpercatinib**, a highly selective small molecule inhibitor of the RET (rearranged during transfection) receptor tyrosine kinase, and **omeprazole**, a proton pump inhibitor that reduces gastric acidity. Selpercatinib is indicated for RET fusion-positive non-small cell lung cancer and RET-mutant or fusion-positive thyroid cancers. Omeprazole is used primarily for gastroesophageal reflux and peptic ulcer disease. Concomitant use of these drugs decreases the absorption and serum concentration of selpercatinib due to reduced gastric acidity from omeprazole, potentially compromising the efficacy of selpercatinib. Their coadministration is generally advised against except when no alternatives exist, in which case selpercatinib should be administered with food[1][2][3][4].