Atovaquone (Mepron - Burroughs Wellcome), a hydroxynaphthoquinone, was recently approved by the US Food and Drug Administration (FDA) for oral treatment of mild to moderate Pneumocystis carinii pneumonia (PCP) in patients who cannot tolerate trimethoprim-sulfamethoxazole (Septra, Bactrim, and others). PCP is a common opportunistic infection and frequent cause of death in patients with AIDS.

The US Food and Drug Administration has approved use of the angiotensin-converting enzyme (ACE) inhibitor captopril (Capoten) for patients with left ventricular dysfunction after a myocardial infarction. ACE inhibitors, widely used for treatment of hypertension, in recent years have also been used for treatment of heart failure (Medical Letter, 35:40, 1993).

Thalidomide is now available as an investigational drug in the USA. A synthetic derivative of glutamic acid, it was marketed in Europe in 1957 as a sedative but withdrawn four years later after being associated with severe human teratogenicity (PF DArcy and JP Griffin, Adverse Drug React Toxicol Rev, 13:65, 1994). The drug has since been found effective for several different indications.

Anastrozole (Arimidex - Zeneca), a selective nonsteroidal aromatase inhibitor, has been approved by the US Food and Drug Administration (FDA) for treatment of postmenopausal women with advanced breast cancer that has progressed during treatment with tamoxifen (Nolvadex, and others).

Sodium phenylbutyrate, an "orphan drug,"has recently been marketed for the treatment of patients with urea cycle disorders caused by a deficiency in one of the following hepatic enzymes: carbamyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS). Urea cycle disorders are rare; they occur in one of every 10,000 births.

Irbesartan (Avapro - Sanofi/Bristol-Myers Squibb) is the third angiotensin II receptor antagonist to become available in the USA for oral treatment of hypertension. Losartan (Cozaar) and valsartan (Diovan) were marketed earlier. Eprosartan (Teveten - SmithKline Beecham) has been approved by the FDA but not marketed.

Sodium hyaluronate (Hyalgan - Sanofi) and hylan G-F 20 (Synvisc - Wyeth- Ayerst) have been approved by the FDA for intra-articular injections in patients with knee pain due to osteoarthritis. Hylan G-F 20 is a cross-linked derivative of hyaluronic acid with a higher molecular weight than sodium hyaluronate. 'Hyaluronan' refers to either the acid or its salt.

The US Food and Drug Administration has ordered removal of phenylpropanolamine from over-the-counter cold remedies and weight loss aids. The FDA based its decision on a recent study showing an increased risk of hemorrhagic stroke in young women taking the drug.

The FDA has approved a new formulation of fluoxetine for once-weekly maintenance treatment of depression in patients who have responded to daily fluoxetine (Prozac).

The media recently reported that the FDA has threatened to withdraw Synthroid from the market, alarming many physicians and patients.