Coadministration has not been studied but based on metabolism and clearance a clinically significant interaction is unlikely. Roxatidine acetate is rapidly metabolised by esterases to its active metabolite roxatidine. Metabolism of roxatidine involves minimal contribution from CYP enzymes (CYP2A6 and CYP2D6). Dolutegravir is mainly metabolized by UGT1A1 and to a lesser extent by CYP3A4. Lamivudine is eliminated renally. Dolutegravir is unlikely to affect roxatidine metabolism. Roxatidine is unlikely to affect UGT1A1 and does not inhibit or induce CYP3A4. No interaction is expected with lamivudine. Data from an interaction study with omeprazole suggest that solubility of dolutegravir is not influenced by changes in gastric pH. Dolutegravir may be coadministered with PPIs or H2-antagonists without dose adjustment or separation.