Garg S K, Kumar N, Bhargava V K, Prabhakar S K
Department of Pharmacology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Clin Pharmacol Ther. 1998 Sep;64(3):286-8. doi: 10.1016/S0009-9236(98)90177-1.
To examine the effect of grapefruit juice on the bioavailability of carbamazepine in patients with epilepsy.
This was a randomized crossover study consisting of 2 phases. Ten patients with epilepsy who had received therapy with 200 mg carbamazepine 3 times a day for the previous 3 to 4 weeks participated. They were given either grapefruit juice or 300 mL water at 8 am along with 200 mg carbamazepine. Each treatment was separated by 2 days; subjects continued to receive carbamazepine therapy during the 2-day period. On both occasions, blood samples were collected at different time intervals between 0 to 8 hours. Carbamazepine levels were estimated by reversed-phase HPLC technique.
Compared with water, grapefruit significantly increased the steady peak concentration (6.55 versus 9.20 microgram/mL), trough concentration (4.51 versus 6.28 microgram/mL), and area under the plasma concentration-time curve (43.99 versus 61.95 micrograms.h/mL) of carbamazepine. No significant effect was found in the time to reach peak plasma concentration.
Grapefruit juice increases the bioavailability of carbamazepine by inhibiting CYP3A4 enzymes in gut wall and in the liver.
研究葡萄柚汁对癫痫患者卡马西平生物利用度的影响。
这是一项随机交叉研究，包括两个阶段。10名癫痫患者参与了研究，他们在过去3至4周内每天接受3次200毫克卡马西平治疗。上午8点，他们分别饮用葡萄柚汁或300毫升水，并同时服用200毫克卡马西平。每次治疗间隔2天；在此期间，受试者继续接受卡马西平治疗。两次试验中，均在0至8小时内的不同时间间隔采集血样。采用反相高效液相色谱技术测定卡马西平水平。
与水相比，葡萄柚显著提高了卡马西平的稳态峰浓度（6.55对9.20微克/毫升）、谷浓度（4.51对6.28微克/毫升）以及血浆浓度-时间曲线下面积（43.99对61.95微克·小时/毫升）。达到血浆峰浓度的时间未发现显著影响。
葡萄柚汁通过抑制肠道壁和肝脏中的CYP3A4酶来提高卡马西平的生物利用度。
