Coadministration with iron supplements decreased dolutegravir AUC, Cmax and Cmin by 54%, 57% and 56%, respectively. Iron supplements should be taken well separated in time from the administration of dolutegravir (minimum 2 hours after or 6 hours before). Factors that decrease dolutegravir exposure should be avoided in the presence of integrase class resistance. This includes co-administration with medicinal products that reduce dolutegravir exposure (e.g. iron supplements).

Coadministration may decrease dolutegravir concentrations. Coadministration of ferrous fumarate (324 mg) and dolutegravir (50 mg single dose) was studied under fasted, fed and temporally separated conditions. Simultaneous coadministration to fasting subjects (n=11) decreased dolutegravir Cmax, AUC and Cmin by 57%, 54% and 56%, respectively. Simultaneous coadministration to fed subjects (n=11) increased dolutegravir Cmax by 3%, decreased AUC by 2%, and had no effect on Cmin. Coadministration of ferrous fumarate 2 h after dolutegravir (n=10) decreased dolutegravir Cmax, AUC and Cmin by 1%, 5% and 8%, respectively. Administer dolutegravir 2 hours before or 6 hours after taking supplements containing iron. Alternatively, dolutegravir and supplements containing calcium can be taken together with food.

Coadministration of ferrous fumarate (324 mg) and dolutegravir (50 mg single dose) was studied under fasted, fed and temporally separated conditions. Simultaneous coadministration to fasting subjects (n=11) decreased dolutegravir Cmax, AUC and Cmin by 57%, 54% and 56%, respectively. Simultaneous coadministration to fed subjects (n=11) increased dolutegravir Cmax by 3%, decreased AUC by 2%, and had no effect on Cmin. Coadministration of ferrous fumarate 2 h after dolutegravir (n=10) decreased dolutegravir Cmax, AUC and Cmin by 1%, 5% and 8%, respectively. Dolutegravir and iron supplements can be co-administered if taken with a meal. Under fasted conditions, dolutegravir should be administered 2 hours before or 6 hours after iron supplements.