Coadministration has not been studied. Cyanocobalamin undergoes enterohepatic recycling and is excreted almost entirely in the urine. No interaction is expected with vitamin B12 when given as a single agent (i.e. not in a multivitamin preparation) or as an injection. However, vitamin B12 can be found in multivitamin preparations; simultaneous coadministration of a multivitamin preparation decreased dolutegravir exposure by ~33%. Dolutegravir should be administered 2 hours before or 6 hours after medications containing polyvalent cations, such as multivitamin preparations. Medicinal products that reduce dolutegravir exposure (e.g. multivitamins) should be avoided in the presence of integrase class resistance.