Pravastatin (Pravachol - Bristol-Myers Squibb) and simvastatin (Zocor - Merck), two new inhibitors of cholesterol synthesis similar to lovastatin (Mevacor - Merck), have been marketed in Canada and several European countries and may soon be available in the USA for treatment of high plasma cholesterol concentrations. Drugs already marketed here for this indication were recently reviewed in The Medical Letter (Volume 33, page 1, January 11, 1991).

A highly concentrated omega-3 polyunsaturated fatty acid (PUFA) preparation (Omacor - Reliant) has been approved by the FDA as an adjunct to diet for treatment of very high plasma triglyceride concentrations (>=500 mg/dL). Omacor is a combination of the ethyl esters of icosapentaenoic (EPA) and docosahexaenoic (DHA) acids. It is the first drug derived from omega-3 PUFAs to be sold by prescription.

Atorvastatin (Lipitor - Parke-Davis), an HMG-CoA reductase inhibitor (or 'statin'), was recently approved by the US Food and Drug Administration for treatment of primary hypercholesterolemia and mixed dyslipidemia. A single stereoisomer of a pyrrole derivative, the new drug is chemically different from other statins.

Rosuvastatin (Crestor - AstraZeneca), an HMG-CoA reductase inhibitor (or "statin"), was recently approved by the FDA for lowering serum cholesterol and triglyceride concentrations and raising HDL cholesterol levels. Rosuvastatin, like other statins, inhibits the enzyme that catalyzes the rate-limiting step in cholesterol synthesis, but it is claimed to be more potent than the others. All of these drugs must be taken indefinitely; if they are discontinued, lipid levels return to baseline.

The FDA recently approved three new drugs for treatment of hyperlipidemia. Ezetimibe (ez et' i mibe; Zetia) is the first in a new class of drugs that inhibit intestinal absorption of cholesterol. Extended-release lovastatin (Altocor) is a new formulation of lovastatin (Mevacor, and others). Extended-release niacin plus (immediate-release) lovastatin (Advicor) is the first fixed-dose combination of lipid-lowering drugs.

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

The FDA has approved the marketing of fenofibric acid (Trilipix - Abbott) to reduce triglycerides and increase HDL-C in patients with mixed dyslipidemia on optimal doses of a HMG-CoA reductase inhibitor (statin) who have, or have risk factors for, coronary heart disease. It is the first fibrate approved by the FDA specifically for combined use with a statin. Trilipix is also approved as monotherapy for hypertriglyceridemia, hypercholesterolemia and low HDL-C. The patent for Tricor, Abbott's older formulation of fenofibrate, will expire in 2011.

The FDA has approved the oral adenosine triphosphate-citrate lyase (ACL) inhibitor bempedoic acid for use alone (Nexletol – Esperion) and in a fixed-dose combination with the cholesterol absorption inhibitor ezetimibe (Nexlizet) as an adjunct to diet and maximally tolerated statin therapy in adults with heterozygous familial hypercholesterolemia (HeFH) or established atherosclerotic cardiovascular disease (ASCVD) who require additional lowering of LDL-cholesterol (LDL-C). Bempedoic acid is the first ACL inhibitor to be approved in the US.

Fibrates, niacin and fish oil are promoted for treatment of hypertriglyceridemia. HMG-CoA reductase inhibitors (statins) can lower elevated serum concentrations of triglycerides, but less so than fibrates, niacins or fish oil. Lifestyle changes such as weight reduction, exercise and decreasing alcohol intake can also lower serum triglyceride levels and should be tried first.

Advertisements for atorvastatin (Lipitor), the market leader facing generic competition, have been in the news recently in the US. Lovastatin, pravastatin and simvastatin are all available generically at a much lower retail price or lower co-pay than atorvastatin.