The rate-limiting step in cholesterol synthesis is inhibited by:

HMG-CoA is the rate-limiting enzyme in the biosynthesis of cholesterol. Lovastatin and its congeners are structurally similar to HMG-CoA and are therefore competitive inhibitors of the enzyme HMC-COA. They r considered the drug of choice for hyperlipidemias 1 and 3 Cholestyramine is a bile acid binding resin. Probucol is an antioxidant and gemfibrozil is a fibrc acid derivative. Ref: KD Tripathi 8th ed.