Pharmacokinetics and tolerability of chloramphenicol in budgerigars (Melopsittacus undulatus)

Pharmacokinetics and tolerability of chloramphenicol (CP) were evaluated in budgerigars. Following intramuscular administration of CP at 100 and 200 mg/kg of body weight, serum peak concentrations of 35.3 and 90.7 micrograms/ml, respectively, were obtained 0.25 hr following injection, and these values declined with a terminal half-life of 2.5 and 2.7 hr, respectively. Based on these results, an intramuscular dosage regimen of 100 mg/kg of CP 3 times a day or of 200 mg/kg twice daily was recommended as effective against many of the common bacterial infections in budgerigars. Red blood cell count, packed cell volume, hemoglobin, total plasma protein, serum AST, ALT, LDH and CK values were determined after intramuscular injection of either CP or physiological saline 2 or 3 times a day for 5 days. The birds were weighed before and after treatment. Tissue samples from various organs were examined histologically. The most prominent adverse effect was muscular damage at the injection site. A dosage regimen of 200 mg/kg twice daily for 5 days was considered to be safe.