Effects of Grapefruit and Seville Orange Juices on the Pharmacokinetic Properties of Colchicine in Healthy Subjects

In contrast to label warnings based on the literature, grapefruit juice did not affect the pharmacokinetics of colchicine. Seville orange juice paradoxically reduced absorption of colchicine and increased Tmax, but the clinical significance of this is unknown. Contrary to the expected effects of inhibiting the enzymes that metabolize colchicine, neither juice increased exposure to colchicine. However, the absence of a positive control in these studies dictates that caution should be used when applying these results clinically. ClinicalTrials.gov identifiers: NCT00960193 and NCT00984009.