Asunaprevir + Rifampin = Precautionary

Effect on Concentration

Asunaprevir
Decrease
Applies within class?
No
Rifampin
Unknown
Applies within class?
No

Pharmacologic Effects

Asunaprevir
Effect
N/A
Applies within class?
No
Rifampin
Effect
N/A
Applies within class?
No

Interaction History

N/A

Last Updated 22-Nov-2022

Summary

In this study, coadministration of RIF and ASV resulted in modest decrease of ASV exposure, however,monitoring patients for virologic failure of ASV is warranted as PK parameters of ASV were variably affected when coadministered with multiple dose rifampin.

Sources

Rifampin vs asunaprevir ^

Study Design

Two open-label, nonrandomized one-way interaction study, the effect of multiple doses of rifampin (RIF; 600mg once daily) on the pharmacokinetics (PK) of asunaprevir (ASV; 600mg twice daily) was evaluated in healthy subjects. 20 healthy subjects, aged 18-49 years, received ASV 600mg twice daily for 7days (Day 1-7), followed by coadministration of ASV 600mg twice daily and RIF 600mg daily for 7 days (Day 8-14). On Day 7 and 14, serial blood samples were collected over 12 hours to determine ASV concentration. ASV plasma concentrations were determined by Liquid chromatography-tandem mass spectrometry (LC/MS/MS) method.

Study Results

Coadministration with RIF modestly decreased ASV AUC by 21% and Cmax by 5%, but [90% CI] were wide; [0.56,1.09] for AUC and [0.60,1.50] for Cmax.

Study Conclusions

References

T Eley, B He, S Huang, et al. Effect of multiple dose ketoconazole and the effect of multiple dose rifampin on pharmacokinetics of the hcv ns3 protease inhibitor asunaprevir [abstract o_13]. 8th International Workshop On Clinical Pharmacology Of Hepatitis Therapy. Cambridge, MA. ; 2013.