Influence of kinnow juice on the bioavailability of carbamazepine in healthy male volunteers

Kinnow juice produces a marked and variable increase in carbamazepine bioavailability. The pharmacokinetics of carbamazepine was studied after drug administration with 300 mi water or kinnow juice in a randomized cross over trial on nine healthy male volunteers. With kinnow juice peak serum concentration (Cmax) and area under the serum concentration time curve (AUC) was significantly (P < 0.05) increased and time to reach peak serum concentration (tmax) was significantly decreased (p < 0.05) as compared with water. No change was observed in the elimination half life (t1/2) of drug. The mechanism by which kinnow juice enhances carbamazepine bioavailability could be due to inhibition of cytochrome P-450 enzyme, since kinnow juice contains naringin which is considered to be inhibitor of liver microsomal dihydropyridine oxidation.