The News Is Not All Bad, or Good, for Infection Control
McCann, Jean, Drug Topics
As usual, this year's Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), which drew some 16,000 infectious disease specialists, pharmacists, and others to Toronto last month, generated both positive and negative reports.
The bad news: Antimicrobial resistance is still a major, increasing problem. For example, the SENTRY Antimicrobial Surveillance Program reported that antimicrobial resistance in community-acquired respiratory tract infections has reached "serious levels" over the past three years. In the United States, the rate of nonsusceptibility to macrolides (erythromycin, azithromycin, and clarithromycin) now equals the rate of penicillin resistance.
But the good news was also striking. For one thing, there's a new global brain trust, called the Alliance for the Prudent Use of Antibiotics (APUA). Sponsored by Bristol-Myers Squibb, SmithKline Beecham, and a global disease service company called MRL, APUA will collaborate with public health authorities to develop a comprehensive information source called GAARD (Global Advisory on Antibiotic Resistance Data). It will also encourage research in this area. (For further information or to learn how to join the advisory group's efforts, e-mail barbara.souder@ tufts.edu.)
In other good news, pharmaceutical companies reported promising clinical results with new agents and classes of agents as well as better ways to use existing drugs. These included better combinations; better dosing; and, in some cases, short courses rather than prolonged treatment.
Also under considerable discussion was the development of vactines to forestall the development of infections. According to Spotswood Spruance, M.D., of the University of Utah, one such vaccine (see page 29) looked promising in protecting about 74% of initially HSV negative women against genital herpes upon exposure. Also, a vaccine targeting Staphylococcus aureus, which is commonly picked up in health-care settings, reduced by more than half the cases of septicemia in a group of 1,800 kidney dialysis patients.
In children aged one to 12, the use of the oral flu drug oseltamivir (Tamiflu, Roche) during influenza was shown, in a multicenter study, to reduce subsequent otitis media by 56% in children aged one to five and by 40% in the overrall group, compared with children receiving a placebo.
First of a new class
The first of an entirely new family of antibiotics-the ketolides-looks promising, according to the results of 10 phase III multinational trials reported at the conference, and an NDA has been filed with the Food & Drug Administration for the approval of telithromycin tablets (Ketek, Aventis). The 2,500 patients treated with the new drug, which is a novel addition to the macrolide-- lincosamide-streptogramin group of agents, showed favorable responses to several of the common and less common causes of upper respiratory group infections. Subanalyses of the North American study, for instance, showed a 90% cure rate against the most common cause of community-acquired pneumonia, Streptococcus pneumoniae. It also showed activity against S. pyogenes, Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis.
A fourth-generation cephalosporin, cefepime (Maxipime, Dura Pharmaceuticals), was shown to overcome the resistance seen in thirdgeneration drugs caused by extended=spectrum beta-lactamases and AmpC cephalosporinases in a small study of trauma patients at the University of Maryland. Of the 17 seriously ill patients, there was a clinical cure in 13 and a bacteriological cure in 15 against such organisms as Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae, and Citrobacter freundii.
Phase III data were also presented for another addition-in this country-to the cephalosporin class. Currently on the market in Japan, cefditoren pivoxil (Spectracef, TAP Pharmaceuticals) is being reviewed by the FDA for acute exacerbations of chronic bronchitis. …