View the Comparison Chart: Some Drugs for Irritable Bowel Syndrome with Diarrhea (IBS-D)

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.

View the Comparison Chart: Safety of Drugs for IBS in Pregnancy and Lactation

Pravastatin - Bristol-Myers Squibb) and simvastatin (Zocor -Merck), two new inhibitors of cholesterol synthesis similar to lovastatin (Mevacor - Merck), have now been marketed in the USA for treatment of hypercholesterolemia. Lovastatin (Medical Letter, 29:99, 1987) is the most frequently prescribed of all cholesterol-lowering drugs in the USA. Pravastatin and simvastatin were previously reviewed in The Medical Letter when they became available in Canada (volume 33, page 18, 1991).

Fluvastatin (Lescol - Sandoz), an HMG-CoA reductase inhibitor, was recently marketed in the USA for treatment of hypercholesterolemia. A synthetic mevalonolactone derivative, it is chemically distinct from previously available drugs in this class.

Micronized fenofibrate (Tricor - Abbott), a fibric acid derivative structurally similar to clofibrate (Atromid-S, and others) and gemfibrozil (Lopid, and others), has been approved by the FDA for treatment of hypertriglyceridemia. Increased serum triglyceride concentrations have been associated with an increased risk of coronary heart disease (J Jeppesen et al, Circulation, 97:1029, 1998).

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.

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.

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).

Warfarin sodium (Coumadin, and others) and other coumarin anticoagulants prevent thrombosis, but patient response is highly variable and overanticoagulation can lead to hemorrhage. Genotyping patients for single nucleotide polymorphisms (SNPs) that affect coumarin metabolism and sensitivity may help clinicians estimate the therapeutic warfarin dose. The FDA has added a note to warfarin labeling recommending lowrange doses for patients with such genetic variations. Commercial tests for these variants are now available and cost about $500 per test.