Colesevelam hydrochloride (Welchol - Sankyo Pharma), a nonabsorbed hydrophilic polymer that binds bile acids, has been approved by the FDA for reduction of plasma LDL cholesterol in patients with primary hypercholesterolemia.

Cerivastatin (Baycol - Bayer), a new HMG-CoA reductase inhibitor (or "statin"), has been approved by the FDA for treatment of hypercholesterolemia. Cerivastatin is the sodium salt of a synthetic fluorophenyl pyridinyl-substituted heptanoic acid.

Telithromycin (Ketek - Aventis) has been approved by the FDA for oral treatment of mild to moderate community-acquired pneumonia, acute exacerbations of chronic bronchitis and acute bacterial sinusitis in patients age 18 and older. The drug is the first in a new class of antibiotics, the ketolides, derived from the macrolide erythromycin. Telithromycin has been marketed in Europe since 2001.

Serious adverse interactions between drugs continue to be reported. Many of these are due to inhibition or induction of cytochrome P450 (CYP) enzymes, particularly CYP3A4. CYP3A is thought to be involved in the metabolism of more than 50 percent of currently prescribed drugs.2 CYP3A4, which is more abundantly expressed than CYP3A5, accounts for most CYP3A activity in vivo.

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.

Red yeast rice is a food product that has been used in Chinese cooking and medicine for centuries. It is available in the US in a capsule formulation and is often used by patients who want a "natural" product to lower cholesterol.

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.

A recent letter to the editor of the Annals of Internal Medicine documented a single case of myopathy apparently due to an interaction between simvastatin (Zocor, and others) and green tea. Since it became available generically, simvastatin has surpassed atorvastatin (Lipitor) as the best selling statin. As such, it is probably the most common cause of statin-induced myopathy, which is often a result of drug interactions.