title: Efficacy of azithromycin or clarithromycin for prophylaxis of viridans group streptococcus experimental endocarditis.
abstract: The efficacy of azithromycin or clarithromycin was compared to that of amoxicillin, clindamycin, or erythromycin for the prevention of viridans group streptococcus experimental endocarditis. Rabbits with catheter-induced aortic valve vegetations were given no antibiotics or two doses of amoxicillin at 25 mg/kg of body weight, azithromycin at 10 mg/kg, clarithromycin at 10 mg/kg, clindamycin at 40 mg/kg followed by clindamycin at 20 mg/kg, or erythromycin at 10 mg/kg. Antibiotics were administered 0.5 h before and 5.5 h after intravenous infusion of 5 x 10(5) CFU of Streptococcus milleri. Forty-eight hours after bacterial inoculation, the rabbits were killed and aortic valve vegetations were aseptically removed and cultured for bacteria. Infective endocarditis occurred in 88% of untreated animals, 1% of animals receiving amoxicillin, 9% of animals receiving erythromycin, 0% of animals receiving clindamycin, 2.5% of animals receiving clarithromycin, and 1% of animals receiving azithromycin. All five regimens were more effective (P < 0.001) than no prophylaxis. Erythromycin was less effective (P < 0.05) than amoxicillin or clindamycin. Azithromycin or clarithromycin was as effective as amoxicillin, clindamycin, or erythromycin for the prevention of viridans group streptococcus experimental endocarditis in this model.
authors.affiliation: Infectious Diseases Research Laboratory, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Rouse
authors.forename: J M
authors.initials: JM
authors.lastname: Steckelberg
authors.forename: C M
authors.initials: CM
authors.lastname: Brandt
authors.forename: R
authors.initials: R
authors.lastname: Patel
authors.forename: J M
authors.initials: JM
authors.lastname: Miro
authors.forename: W R
authors.initials: WR
authors.lastname: Wilson
mesh_terms: D000658:Amoxicillin / Q000097:blood / Q000627:therapeutic use; D000818:Animals; D000900:Anti-Bacterial Agents / Q000097:blood / Q000627:therapeutic use*; D019072:Antibiotic Prophylaxis; D017963:Azithromycin / Q000097:blood / Q000627:therapeutic use*; D017291:Clarithromycin / Q000097:blood / Q000627:therapeutic use*; D002981:Clindamycin / Q000097:blood / Q000627:therapeutic use; D004697:Endocarditis, Bacterial / Q000097:blood / Q000382:microbiology / Q000517:prevention & control*; D004917:Erythromycin / Q000097:blood / Q000627:therapeutic use; D011817:Rabbits; D013291:Streptococcus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D002981:Clindamycin; D004917:Erythromycin; D000658:Amoxicillin; D017963:Azithromycin; D017291:Clarithromycin