Coadministration of sofosbuvir and raltegravir (400 mg once daily) decreased raltegravir Cmax, AUC and Cmin by 43%, 27% and 5%, respectively. Sofosbuvir Cmax and AUC decreased by 13% and 5%, whereas GS-331007 Cmax and AUC increased by 9% and 3%.  No dose adjustment of sofosbuvir or raltegravir is required when sofosbuvir and raltegravir are used concomitantly.

The interaction between sofosbuvir and raltegravir was evaluated in clinical trials and no dose adjustment is needed for either drug. Coadministration of raltegravir (400 mg once daily) and sofosbuvir (400 mg single dose) was studied in 19 subjects. No effect on the pharmacokinetic parameters of sofosbuvir and GS-331007 was observed. Raltegravir Cmax, AUC and Cmin decreased by 43%, 27% and 5%, respectively.

 

Coadministration a single dose of sofosbuvir (400 mg) before and after 10 days of raltegravir (400 mg twice daily) was studied in 18 subjects. Raltegravir modestly increased sofosbuvir exposure but had no effect on GS-331007, whereas sofosbuvir modestly decreased raltegravir AUC (~27%) and Cmax (~43%).