RIOS AM, FONSECA ATEN M, MEJIAS A, CHAVEZ-BUENO S, GOMEZ AM, RAMILO O, MCCRACKEN GH, HARDY RD; Interscience Conference on Antimicrobial Agents and Chemotherapy (43rd: 2003: Chicago, Ill.).

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2003 Sep 14-17; 43: abstract no. B-1672.

Univ. of Texas Southwestern Medical Center, Dallas, TX.

BACKGROUND: Mycoplasma pneumoniae (Mp) is a major etiologic agent of community-acquired pneumonia. It has been proposed that single high dose therapy with azithromycin (AZ) is equivalent to standard daily dose therapy for certain infections. We evaluated the efficacy of AZ for treatment of Mp pneumonia in a mouse model using 50mg/kg once Vs 10 mg/kg for 5 days. METHODS: 8 week old Balb/c mice were inoculated once intranasally with 10 [7] CFU Mp on day 0. Treatment was started 1 day after inoculation. Groups of mice were treated with AZ subcutaneous 50 mg/kg once, 10 mg/kg for 5 days, or placebo. Groups of 5-10 mice per regimen were evaluated on days 1, 4, 7, 10, and 14 after inoculation. Outcome variables included bronchoalveolar lavage (BAL) Mp cultures, histopathologic score (HPS) of the lungs, and pulmonary function tests (PFT) with whole-body, unrestrained plethysmography (pre and post methacholine), as an indicator of airway obstruction (AO) and airway hyper-reactivity (AHR). RESULTS: Compared with placebo, mice that received AZ demonstrated a greater reduction in Mp culture titers at all time points, reaching statistical significance on day 4 and 7 for both regimens (p < 0.05). The single-dose regimen had a significantly greater reduction in Mp titers at day 7 compared with the daily-dose regimen (p = 0.02). HPS was significantly lower in mice treated with either AZ regimen compared with placebo at all time points (p < 0.05). AO was lower in the AZ mice compared with placebo, with a significant reduction at day 14 for both regimens (p < 0.05). AHR was decreased in AZ mice compared with placebo in all time points with significant reductions on day 7 for the daily dose regimen only (p < 0.05). CONCLUSIONS: Both AZ regimens were effective for experimental Mp pneumonia by reducing Mp titers, decreasing HPS and lessening the severity of AO and AHR. There was no a clear advantage of one regimen over the other.

Publication Types:

• Meeting Abstracts

Keywords:

• Airway Obstruction
• Animals
• Azithromycin
• Clinical Protocols
• Lung
• Methacholine Chloride
• Mice
• Mycoplasma pneumoniae
• Plethysmography, Whole Body
• Pneumonia
• Pneumonia, Mycoplasma
• Single Person
• administration & dosage
• therapy

Other ID:

• GWAIDS0025228

UI: 102264852

From Meeting Abstracts