Fosamprenavir + Telaprevir = Precautionary

Effect on Concentration

Fosamprenavir
Decrease
Applies within class?
No
Telaprevir
Decrease
Applies within class?
No

Pharmacologic Effects

Fosamprenavir
Effect
N/A
Applies within class?
No
Telaprevir
Effect
N/A
Applies within class?
No

Interaction History

N/A

Last Updated 10-Jul-2018

Summary

The manufacturer studied the pharmacokinetic effect of co-administering ritonavir-boosted fosamprenavir with telaprevir. Concentrations of both drugs were decreased.

Sources

Review of drug interactions with telaprevir and antiretrovirals. ^

Study Design

The manufacturer preformed a pharmacokinetic (PK) study on the effect of co-administering darunavir/ritonavir (DRV/rtv) with telaprevir. They examined 600mg/100mg DRV/rtv twice daily for 20 days and 24 days. The 20 day dosing schedule was paired with telaprevir 750mg every 8 hours for 10 days (starting on day 11). The 24 day dosing schedule was evaluated with telaprevir 1125mg every 12 hours for 4 days and was just looking at the effect on darunavir.

Study Results

Effect on telaprevir PK: The average telaprevir PK parameters were DECREASED by: Cmax=36%, AUC= 35%, Cmin=32%. 2.) Effect on darunavir PK when administered for 20 days with telaprevir 750mg every 8 hours for 10 days: The average darunavir PK parameters were DECREASED by: Cmax=40%, AUC=40%, Cmin=42%. 3.) Effect on darunavir PK when administered for 24 days with telaprevir 1125mg every 12 hours for 4 days: The average darunavir PK parameters were DECREASED by: Cmax=47%, AUC=51%, Cmin=58%. The manufacturer states it is NOT recommended to co-administer darunavir/ritonavir with telaprevir.

Study Conclusions

*The above interaction information is only for darunavir boosted with ritonavir, and not darunavir administered alone. There is no information available on the interaction of darunavir without ritonavir.

References

Van Heeswijk RP, Beumont M, Kauffman RS, Garg V. Review of drug interactions with telaprevir and antiretrovirals. Antiviral Therapy. 2013; 4: 553-560.