Atazanavir/Ritonavir + Grazoprevir (Single Agent) = Precautionary

Effect on Concentration

Atazanavir/Ritonavir
No change
Applies within class?
No
Grazoprevir (Single Agent)
Increase
Applies within class?
No

Pharmacologic Effects

Atazanavir/Ritonavir
Effect
N/A
Applies within class?
No
Grazoprevir (Single Agent)
Effect
N/A
Applies within class?
No

Interaction History

N/A

Last Updated 16-Jul-2018

Summary

Sources

Atazanavir/Ritonavir versus Grazoprevir ^

Study Design

In an open-label, 3-period study, 13 healthy subjects with age of 19-55 years old received grazoprevir (GZR, MK-5172) 200 mg once daily for 7 days.1 After a 7-day washout, subjects received atazanavir/ritonavir (ATV/r) 300/100 mg daily for 14 days, followed by coadministration of GZR 200 mg daily plus ATV/r 300/100 mg daily for 7 days.

Study Results

Coadministration of GZR and ATV/r resulted in significant increase of GZR exposure; geometric mean ratio (GMR; ATV/r+ GZR / GZR) [90% CI] of AUC was 10.58 [7.78, 14.39].1 GZR modestly increased ATV exposure; GMR (ATV/r+GZR / ATV/r) [90%CI] of AUC was 1.43 [1.30, 1.57].

Study Conclusions

Concomitant use of ATV/r and GZR is not recommended until further data is available.2 Although no clinical study has been done for unboosted ATV vs GZR, the investigators proposed that unboosted ATV and GZR should not be coadministered.

References

El-Sherif O, Back D. Drug interactions of hepatitis c direct-acting antivirals in the hiv-infected person. Current Hiv/aids Reports. 2015; 3: 336-343.