Pharmacokinetic and clinical studies of the carbapenem antibiotic, meropenem, in birds

摘要

Meropenem (Meropenem powder, Zeneca GmbH, Plankstadt, Germany), a new carbapenem (b-lactam) antibiotic, was tested. In sensitivity testing of bacteria, isolated from patients of our clinic, Meropenem showed the best antimicrobial activity of all tested antibiotics against gram-negative and gram-positive germs. Using pigeons as an avian model, we examined pharmacokinetic data in blood plasma and developed a dosage recommendation (175 mg/kg intramuscular [IM] q24h). This dosage resulted in concentrations of 250 mg/L after 30 minutes and 0.4 mg/L after 8 hours. The concentrations over time show a rapid absorption from the injection site that should guarantee an immediate bactericidal effect against the most sensitive pathogens. Toxicity was evaluatedin healthy pigeons over a 10-day period with the therapeutic dosage. No significant Meropenem-induced changes in blood chemistries or any serious macroscopic alterations on necropsy were observed. In addition, we investigated changes in the microbial cloacal flora resulting from treatment with Meropenem. All gram-negative germs were eliminated, but Enterococci species resistant to Meropenem and yeasts were observed. Positive results with Meropenem in pigeons have been the basis for clinical studies inpsittacine and other exotic birds.