GRAVENSTEIN S, DRINKA P, OSTERWEIL D, SCHILLING M, MCELHANEY J, ELLIOTT M, HAMMOND J, KEENE O, KRAUSE P, FLACK N; Interscience Conference on Antimicrobial Agents and Chemotherapy.

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2000 Sep 17-20; 40: 270.

Eastern Virginia Med. Sch., Norfolk, VA

BACKGROUND: The neuraminidase inhibitor zanamivir (Relenza[TM], GlaxoWellcome) is safe and effective for treatment of influenza A and B in healthy adults. We hypothesized it to be safe and effective for chemoprophylaxis of influenza A and B in an 86% vaccinated Long Term Care Facility (LTCF) population.METHODS: Subjects were randomized double-blind to zanamivir chemoprophylaxis (10 mg qd) or standard of care (SOC) for 14 days when an influenza outbreak was declared. The SOC for outbreak control in participating LTCFs was rimantadine (100 mg qd) for influenza A and placebo for influenza B. Subjects could be randomized for more than one outbreak.RESULTS: 375 subjects were randomized over 3 influenza seasons at 8 participating centers. Influenza A was responsible for 95% of outbreaks. 280 subjects were randomized once, 83 twice, 12 three times. In the ITT population when all randomizations for each patient were included, 18/244 (7.4%) SOC recipients developed laboratory confirmed clinical influenza (LCCI) compared to 7/238 (2.9%) zanamivir recipients (Relative risk: 0.39; 95% CI: 0.18, 0.88; p=0.038). In an analysis including only the first randomization, 16/191 (8.4%) subjects randomized to SOC developed LCCI compared to 7/184 (3.8%) subjects receiving zanamivir ( RR: 0.44; 95% CI: 0.19, 1.02; p=0.085). SOC and zanamivir recipients had similar clinical and laboratory measures of safety. Rimantadine resistance occurred in 8/25 prophylaxis failures, and zanamivir resistance in 0/25.CONCLUSIONS: Zanamivir is more effective than rimantadine in preventing LTCF influenza during an influenza outbreak. Zanamivir is less permissive to the development of antiviral resistance than rimantadine, which may be an important advantage in its use for outbreak control.KEYWORDS: Influenza; Nursing home; Prophylaxis

Publication Types:

• Meeting Abstracts

Keywords:

• Adult
• Antiviral Agents
• Clinical Trials as Topic
• Disease Outbreaks
• Double-Blind Method
• Humans
• Influenza Vaccines
• Longitudinal Studies
• Nursing Homes
• Prospective Studies
• Rimantadine
• Safety
• Sialic Acids
• Zanamivir

Other ID:

• GWAIDS0011333

UI: 102248831

From Meeting Abstracts