Amprenavir + Colchicine = Precautionary

Effect on Concentration

Amprenavir
No change
Applies within class?
No
Colchicine
Increase
Applies within class?
No

Pharmacologic Effects

Amprenavir
Effect
N/A
Applies within class?
No
Colchicine
Effect
N/A
Applies within class?
No

Interaction History

N/A

Last Updated 14-Aug-2018

Summary

Sources

Novel evidence-based colchicine dose-reduction algorithm to predict and prevent colchicine toxicity in the presence of cytochrome P450 3A4/P-glycoprotein inhibitors. ^

Study Design

This combination has not been studied in formal interaction studies, but inferences can be made based upon what is known of the metabolic pathways of these agents.

Study Results

Colchicine is a a substrate and inhibitor of CYP3A4 and P-glycoprotein. Significant increases in colchicine plasma concentrations are expected when co-administered with ritonavir boosted protease inhibitors

Study Conclusions

Dose modifications are necessary when colchicine is co-administered with boosted protease inhibitors. In patients with renal or hepatic impairment, co-administration of colchicine and protease inhibitors is contraindicated. The manufacturer of tipranavir recommends the following dose adjustments in patients with normal renal and hepatic function receiving boosted protease inhibitors in combination with colchicine: Treatment of gout flares: Co-administration of colchicine in patients on tipranavir/ritonavir: • 0.6 mg x 1 dose, followed by 0.3 mg 1 hour later. Next dose to be repeated no earlier than 3 days later. Prophylaxis of gout flares: Co-administration of colchicine in patients on tipranavir/ritonavir: • If the original colchicine regimen was 0.6 mg twice a day, the regimen should be adjusted to 0.3 mg once a day. • If the original colchicine regimen was 0.6 mg once a day, the regimen should be adjusted to 0.3 mg once every other day. Treatment of familial Mediterranean fever (FMF): Co-administration of colchicine in patients on tipranavir/ritonavir: • Maximum daily dose of 0.6 mg (may be given as 0.3 mg twice a day). *** The above information was released in an FDA Drug Safety Labeling announcement for Aptivus (tipranavir) in April 2014.

References

Terkeltaub RA, Furst DE, DiGiacinto JL. Novel evidence-based colchicine dose-reduction algorithm to predict and prevent colchicine toxicity in the presence of cytochrome p450 3a4/p-glycoprotein inhibitors. Arthritis And Rheumatism. 2011; 8: 2226-2237.