Mevastatin is structurally similar to the HMG, a substituent of the endogenous substrate of HMG-CoA reductase. Mevastatin is a prodrug that is activated in vivo via hydrolysis of the lactone ring. The hydrolyzed lactone ring mimics the tetrahedral intermediate produced by the reductase allowing the agent to bind with 10, 000 times greater affinity than its natural substrate. The bicyclic portion of mevastatin binds to the coenzyme A portion of the active site.
The primary cause of cardiovascular disease is atherosclerotic plaque formation. Sustained elevations of cholesterol in the blood increase the risk of cardiovascular disease. Mevastatin lowers hepatic production of cholesterol by competitively inhibiting HMG-CoA reductase, the enzyme that catalyzes the rate-limiting step in the cholesterol biosynthesis pathway via the mevalonic acid pathway. Decreased hepatic cholesterol levels causes increased uptake of low density lipoprotein (LDL) cholesterol and reduces cholesterol levels in the circulation.
Side effects include those of other statins, such as myalgias, abdominal pain, nausea. It also has a higher chance of giving more severe side effects related to myotoxicity (myopathy, myositis, rhabdomyolysis), and hepatotoxicity, than other statins. Due to these major side effects and their enhanced rate of occurance, Mevastatin is not given therapeutically.