Pravastatin sodium, a new HMG-CoA reductase inhibitor

The rate-limiting step in cholesterol biosynthesis is controlled by the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. Inhibitors of this enzyme lower serum cholesterol very efficiently by increasing cellular uptake of cholesterol-rich, low-density lipoproteins. Pravastatin, a derivative of mevastatin and in the same class as lovastatin, lowers total cholesterol concentrations by 20-30 percent in patients with hypercholesterolemia. In patients who also have hypertriglyceridemia, serum triglyceride levels are decreased. Detailed pharmacokinetic data and long-term adverse-effect experience with pravastatin are extremely limited. The issue of tissue-selectivity for pravastatin has given rise to the marketing terminology "second-generation" HMG-CoA reductase inhibitor, but any clinical advantage of pravastatin over other HMG-CoA reductase inhibitors remains to be demonstrated.