Coadministration with dolutegravir/rilpivirine has not been studied. Data from an interaction study with omeprazole suggest that solubility of dolutegravir is not influenced by changes in gastric pH. However, coadministration may reduce rilpivirine absorption due to gastric pH increase.  Coadministration of rilpivirine (150 mg single dose) and famotidine (40 mg single dose) administered 2 hours before rilpivirine, decreased rilpivirine Cmax and AUC by 85% and 76%. Coadministration of famotidine 12 hours before rilpivirine decreased rilpivirine Cmax and AUC by 1% and 9%; coadministration of famotidine 4 hours after rilpivirine increased rilpivirine Cmax and AUC by 21% and 13%. [Note: this interaction study has been performed with a dose higher than the licensed dose for rilpivirine assessing the maximal effect on the co-administered drug. The dosing recommendation is applicable to the licensed dose of rilpivirine 25 mg once daily.] The combination of dolutegravir/rilpivirine and H2-receptor antagonists should be used with particular caution. Only H2-receptor antagonists that can be dosed once daily should be used and should be taken at least 4 hours after or 12 hours before dolutegravir/rilpivirine.