raltegravir + omeprazole

**Raltegravir + omeprazole** is a non-formulary, non-fixed-dose combination referring to the coadministration of raltegravir, an HIV-1 integrase strand transfer inhibitor, and omeprazole, a proton pump inhibitor. Raltegravir inhibits the catalytic activity of HIV-1 integrase, thereby preventing the integration of viral DNA into the host genome, which blocks HIV replication. Omeprazole suppresses gastric acid secretion by inhibiting the hydrogen-potassium ATPase pump in gastric parietal cells, resulting in increased gastric pH. Omeprazole is often used for conditions like gastroesophageal reflux disease (GERD) or peptic ulcer disease. Coadministration of omeprazole with raltegravir leads to modestly increased plasma concentrations of raltegravir due to increased gastric pH, which enhances the solubility and bioavailability of raltegravir. This interaction does not result in clinically significant safety or efficacy concerns and does not require dose adjustment of either drug in HIV-infected patients[1][2][3][4][5].