Based on drug interaction studies conducted with the components of Stribild, no clinically significant drug interactions have been either observed or are expected between the components of Stribild and omeprazole.
Stribild Summary of Product Characteristics, Gilead Sciences International Ltd, November 2021.

Coadministration of omeprazole (40 mg once daily given 2 hours before elvitegravir) and elvitegravir/ritonavir (50/100 mg once daily) decreasedelvitegravir Cmax, AUC and Cmin by 7%, 1% and 6%, respectively (n=9). Coadministration of omeprazole (20 mg once daily given 2 hours before elvitegravir) and elvitegravir/cobicistat (150/150 mg once daily) increased elvitegravir Cmax, AUC and Cmin by 16%, 10% and 13%, respectively (n=11). When omeprazole (20 mg once daily ) and elvitegravir/cobicistat (150/150 mg once daily) were given 12 hours apart, elvitegravir Cmax, AUC and Cmin increased by 3%, 5% and 10%, respectively (n=11).

 

The effects of omeprazole (20 mg once daily) on the pharmacokinetics of elvitegravir/cobicistat were studied in HIV-negative subjects. When omeprazole was administered 2 h prior to elvitegravir/cobicistat, the AUC and Cmax of elvitegravir increased by 10% and 16% but those of cobicistat decreased by 8% and 10%. Separating omeprazole and elvitegravir/cobicistat by 12 h had no effect (<10% change) on the AUC or Cmax of elvitegravir or cobicistat. No dosing restrictions are necessary on the administration of elvitegravir/cobicistat with proton pump inhibitors.