acerola and Crixivan Interactions

Interactions between acerola(ascorbic acid) and Crixivan (indinavir)

ascorbic acid and indinavir (Minor Drug-Drug)

Coadministration with high dosages of vitamin C (1 g/day or more) may decrease the plasma concentrations of indinavir and other protease inhibitors. The exact mechanism of interaction is unknown, although preliminary data suggest that vitamin C may induce CYP450 3A4, the isoenzyme responsible for the metabolic clearance of protease inhibitors. In seven healthy volunteers, vitamin C (1000 mg daily for 7 days) decreased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of indinavir (800 mg for 4 doses, 8 hours apart) by 20% and 14%, respectively, compared to administration of indinavir alone. Mean indinavir trough plasma concentration (Cmin) was 32% lower with vitamin C, but the difference was not statistically significant. There was no significant difference in indinavir oral clearance and elimination half-life. The clinical relevance of this interaction is uncertain. A study involving a larger number of patients and use of higher dosages of vitamin C would be helpful.