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.

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).

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.

Leflunomide (Arava - Hoechst Marion Roussel), which inhibits pyrimidine synthesis, and etanercept (Enbrel - Immunex/Wyeth-Ayerst), which blocks the action of tumor necrosis factor (TNF), have been approved by the FDA for treatment of rheumatoid arthritis. A third drug, infliximab (Remicade - Centocor), which also blocks TNF and has been used to treat rheumatoid arthritis, was approved earlier for treatment of Crohn's disease. Its use in Crohn's disease will be reviewed in a future issue.

View Figure: Treatments for Irritable Bowel Syndrome (IBS) in Adults

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.

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

Raloxifene (Evista - Lilly), a benzothiophene that acts on estrogen receptors, has recently been marketed for prevention of postmenopausal osteoporosis. Only estrogen (alone or in combination with a progestin) and the bisphosphonate alendronate (Fosamax) were previously approved by the FDA for this indication.

The gram-positive bacillus Clostridium difficile is the most common identifiable cause of antibiotic-associated diarrhea and pseudomembranous colitis (R Fekety in GL Mandell et al, eds, Principles and Practice of Infectious Diseases, 3rd ed, New York:Churchill Livingstone, 1990, page 863). C. difficile colitis usually develops during or soon after antibiotic treatment. Virtually any antimicrobial agent can cause the disorder, but clindamycin, ampicillin and the cephalosporins have been implicated most frequently. Pseudomembranous colitis was recently reported in five patients who had ...

Mycophenolate mofetil (CellCept - Roche) has been approved by the US Food and Drug Administration for oral use in preventing organ rejection in patients receiving allogeneic renal transplants. It is being promoted as an improvement over azathioprine (Imuran) for concurrent use with cyclosporine (Sandimmune; Neoral) and corticosteroids.