Lack of pharmacokinetic interaction between grapefruit juice and phenytoin in healthy male volunteers and epileptic patients.
The present study was undertaken to determine the effects of grapefruit juice (GFJ) on the oral bioavailability of phenytoin (DPH). Ten healthy male volunteers received a single dose of 300 mg of DPH orally with 300 ml of water or fresh GFJ in a randomized crossover fashion. In both instances, blood sampling was done at 0, 0.5, 1, 2, 4, 6, 9, 12, 24, 48, 72, 96 and 120 h. The study was also carried out in 10 epileptic patients with uncontrolled seizures even after 3 to 4 weeks regular therapy of DPH (100 mg three times a day). Blood samples were drawn at 0, 1, 2, 3, 4, 5, 6 and 8 h after DPH with 300 ml of water or fresh GFJ. No significant difference was observed in any of the pharmacokinetic parameters like Cmax, Cmin, Tmax, t1/2a, t1/2e and AUC of DPH after GFJ administration as compared to control values in healthy volunteers and epileptic patients. It is concluded that GFJ does not affect the oral bioavailability of DPH.
Kumar
N
N
Department of Pharmacology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Garg
S K
SK
Prabhakar
S
S
D000328:Adult; D000927:Anticonvulsants / Q000097:blood / Q000493:pharmacokinetics; D004347:Drug Interactions; D004827:Epilepsy / Q000378:metabolism*; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010672:Phenytoin / Q000097:blood / Q000493:pharmacokinetics*; D012640:Seizures / Q000378:metabolism*; D013997:Time Factors
D000927:Anticonvulsants; D010672:Phenytoin