コレステロール負荷食ウサギの脂質異常に対するPravastatin先発医薬品と後発医薬品の効果 Effect of the Brand and Generic Medicine of Pravastatin on Dyslipidemia in Rabbits Fed a High Cholesterol Diet

  Mevalotin^® containing pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, is the brand medicine and well known to be effective for patients with dyslipidemia. Now, more than 20 generic pravastatins are available for clinical therapy. We compared pharmaceutical property of Mevan^®, a generic pravastatin, with that of Mevalotin^®. According to the definition of the Japanese Pharmacopoeia, Mevalotin^® 10 mg tablets were uniform in pravastatin content, whereas 5 mg tablets were rather variable. Variation in pravastatin content of Mevan 5 mg tablets was the same as Mevalotin^® 5 mg, whereas that of 10 mg tablets was very variable. The plasma concentration of pravastatin in the normal rabbits continuously increased until 180 min after oral administration of 30 mg Mevan^®, whereas it increased in a biphasic pattern after 30 mg Mevalotin^®. All rabbits were fed 0.2% cholesterol diet throughout the experiment. After 8 weeks, oral administration of either Mevalotin^® or Mevan^® was started at the dose of 30 mg pravastatin/day for 16 weeks. After a transient increase for a few weeks, the plasma levels of total- and LDL-cholesterol gradually decreased in Mevalotin^® group, whereas these levels did not significantly changed in Mevan^® group within 16 weeks. The level of HDL-cholesterol in Mevan^® group tended to increase but not in Mevalotin^® group. The triglyceride level in Mevan^® group changed as well as that in Mevalotin^® group until 10 weeks after administration, and then gradually increased. The present results suggest that pharmaceutical properties of Mevan^® are not always identical with those of Mevalotin^®.<br>