Coadministration with a drospirenone progestogen-only pill (POP) has not been studied. CYP3A4 contributes to drospirenone metabolism. No interaction is expected with emtricitabine or tenofovir alafenamide but darunavir/cobicistat is predicted to increase drospirenone and clinical monitoring is recommended due to the potential for hyperkalaemia. Drospirenone AUC increased by 58% when a combined oral contraceptive containing drospirenone and ethinylestradiol was coadministered with darunavir/cobicistat. Based on studies with norethisterone used as a progestogen only pill, the contraceptive efficacy of a drospirenone POP is unlikely to be compromised by darunavir/cobicistat.