Zileuton (zye loo' ton; Zyflo - Abbott), an inhibitor of leukotriene synthesis, has been approved by the US Food and Drug Administration (FDA) for prophylaxis and maintenance treatment of chronic asthma in adults and children more than 12 years old. A related drug—zafirlukast (Accolate), a leukotriene receptor antagonist—was recently reviewed in the Medical Letter (vol. 38, page 111, December 20, 1996). Neither of these drugs is recommended for treatment of acute asthma.

Sildenafil citrate (Viagra - Pfizer) is the first oral drug approved by the FDA for treatment of erectile dysfunction. Alprostadil is also marketed for this indication but must be injected into the corpus cavemosum (Caverject) or pushed into the urethra (MUSE).

Rebetron, a combination of injected recombinant interferon alfa-2b with oral ribavirin has been approved by the FDA for treatment of chronic hepatitis C virus infection.

Rivastigmine tartrate (Exelon - Novartis), a carbamate-based cholinesterase inhibitor, is now being marketed for treatment of patients with dementia due to Alzheimer's disease.

The FDA had approved an intrauterine contraceptive device that releases the synthetic progestin levonorgestrel over a period of five years. The device has been available in Europe for 10 years.

Tinzaparin sodium, a low molecular weight heparin, has been approved by the FDA for treatment of acute deep vein thrombosis.

Galantamine hydrobromide (Reminyl), a tertiary alkaloid and phenanthrene derivative extracted from daffodil bulbs, is now being marketed for oral treatment of mild to moderate Alzheimer's disease. Galantamine is the fourth acetylcholinesterase inhibitor approved for this indication.

Botulinum toxin type A (Botox - Allergan) has been approved by the FDA for treatment of severe underarm sweating ("primary axillary hyperhidrosis"). Injected into the skin, botulinum toxin decreases sweating by causing chemical denervation of the sweat gland.

A new albumin-bound formulation of paclitaxel (Abraxane - American Pharmaceutical Partners) has been approved by the FDA for treatment of metastatic breast cancer after failure of combination chemotherapy or relapse within 6 months of adjuvant chemotherapy. This formulation is free of polyoxyethylated castor oil (Cremophor), a solvent thought to contribute to the hypersensitivity reactions that occur frequently with standard paclitaxel (Taxol, and others) and are severe in about 3% of patients.

Belimumab (Benlysta – Human Genome Sciences/GlaxoSmithKline) has been approved by the FDA for treatment of adults with active, autoantibody-positive, systemic lupus erythematosus (SLE). It is the first biologic agent approved for SLE and the first drug of any kind to be approved for this disease in >50 years.