Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

Paclitaxel (Taxol - Bristol-Myers Squibb) is now available in the USA for treatment of metastatic ovarian cancer refractory to other drugs. The new drug is a natural product extracted in small amounts from the inner bark of the Western yew tree found mainly in the Pacific northwest (Taxus brevifolia). Efforts to synthesize the drug have been unsuccessful to date, but a semi-synthetic product (taxotere) prepared from the needles of European yews has shown some promise (R Pazdur et al, J Natl Cancer Inst, 89:1781, 1992), and a fungus (Taxomyces andreanae) growing on the Pacific yew was...

Cilostazol, a phosphodiesterase III inhibitor that has been used in Japan since 1988, has been approved by the FDA for treatment on intermittent claudication due to occlusive peripheral arterial disease.

Many drugs, mostly azole derivatives, are marketed in the USA for topical treatment of vulvovaginal candidiasis. A single-dose, sustained-release formulation of butoconazole nitrate 2% cream (Gynazole 1) is the newest addition. Fluconazole (Diflucan) is approved for single-dose oral treatment.

The FDA has approved an extended-release (XR) formulation of the benzodiazepine alprazolam (Xanax XR - Pfizer) for treatment of panic disorder, with or without agoraphobia. The new formulation is intended to reduce the need for frequent dosing and problems of interdose anxiety. This review describes the effectiveness of the extended-release formulation, as well as sections on dependence, abuse and withdrawal, adverse effects, and drug interactions. The review concludes with an overall assessment of the drug's efficacy and cost.

The drugs of choice for treatment of fungal infections are listed in the table that begins on page 62. Some of the indications and dosages recommended here have not been approved by the FDA. More detailed guidelines for some of these infections are available online from the Infectious Diseases Society of America (www.idsociety.org).

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.

Dofetilide (Tikosyn - Pfizer), a new methanesulfonamide antiarrhythmic drug, has recently been marketed for oral treatment of atrial fibrillation and flutter.

Mifepristone (RU 486; Mifeprex - Danco), an antiprogestin, has been approved by the FDA for termination of intrauterine pregnancies of 49 days or less. It is generally used with misoprostol (Cytotec - Searle), an E₁ prostaglandin analog marketed in the USA only for prevention of gastric ulcers.

Tadalafil (Cialis - Lilly Icos) is the third oral drug to be approved by the FDA for treatment of erectile dysfunction. It has a longer duration of action than sildenafil (Viagra) or vardenafil (Levitra - Medical Letter 2003; 45:77).