Fauler G, Abletshauser C, Erwa W, Löser R, Witschital K, März W
Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University Graz, Austria.
Int J Clin Pharmacol Ther. 2007 Jun;45(6):328-34. doi: 10.5414/cpp45328.
Statins inhibit the rate-limiting step in cholesterol biosynthesis, the conversion of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) to mevalonate by HMG-CoA reductase. Statins are usually taken in the evening as the HMG-CoA reductase activity is high during the night. This recommendation might not apply if statins are given as extended-release (ER) formulations. The present study investigated the influence of time of intake of fluvastatin 80 mg ER on cholesterol biosynthesis. Main objectives were to measure the change in 24-hour urinary mevalonic acid excretion, to determine plasma concentrations of mevalonic acid and fluvastatin and to monitor triglycerides, total cholesterol, HDL-cholesterol and LDL-cholesterol.
This was a randomized, 2-period crossover study in 26 hypercholesterolemic patients who received a single daily dose of fluvastatin both in the morning and in the evening.
At baseline, the amount of mevalonic acid was 204.9 +/- 68.1 microg/g creatinine. After a single dose of fluvastatin mean urine values of mevalonate were significantly reduced to 129.8 +/- 66.2 micro/g (evening) and to 118.7 +/-34.3 microg/g (morning; n.s. between groups), thus representing a reduction of about 39%. Compared to baseline, plasma mevalonate concentrations were decreased by fluvastatin resulting in similar 24-hour profiles after the morning and the evening dosage. The pharmacokinetics of fluvastatin were similar in both periods of the study, with higher plasma concentrations for several hours following the evening dosage.
This study demonstrates that fluvastatin ER is equally effective in inhibiting cholesterol biosynthesis when given once daily in the morning and once daily in the evening.
他汀类药物可抑制胆固醇生物合成的限速步骤,即3-羟基-3-甲基戊二酰辅酶A(HMG-CoA)被HMG-CoA还原酶转化为甲羟戊酸。由于夜间HMG-CoA还原酶活性较高,他汀类药物通常在晚上服用。如果使用缓释(ER)制剂,这一建议可能并不适用。本研究调查了80毫克氟伐他汀缓释制剂的服用时间对胆固醇生物合成的影响。主要目的是测量24小时尿中甲羟戊酸排泄量的变化,测定甲羟戊酸和氟伐他汀的血浆浓度,并监测甘油三酯、总胆固醇、高密度脂蛋白胆固醇和低密度脂蛋白胆固醇。
这是一项针对26名高胆固醇血症患者的随机、两阶段交叉研究,这些患者每天早晨和晚上各接受一次氟伐他汀单剂量给药。
基线时,甲羟戊酸量为204.9±68.1微克/克肌酐。单次服用氟伐他汀后,甲羟戊酸的平均尿值显著降低至129.8±66.2微克/克(晚上)和118.7±34.3微克/克(早上;两组间无显著差异),因此减少了约39%。与基线相比,氟伐他汀使血浆甲羟戊酸浓度降低,导致早晨和晚上给药后的24小时曲线相似。在研究的两个阶段,氟伐他汀的药代动力学相似,晚上给药后数小时血浆浓度较高。
本研究表明,氟伐他汀缓释制剂每天早晨服用一次和每天晚上服用一次在抑制胆固醇生物合成方面同样有效。