Safety level of Levofloxacin following repeated oral adminstration in White Leg Horn layer birds

Levofloxacin is a fluorinated quinolone which has broad-spectrum antibacterial activity at low plasma/tissue concentration. The present study was designed to investigate safety of levofloxacin (10 mg/kg) after repeated oral administration at 12 hours interval for 14 days in layer birds (30-35 weeks old and weighing between 1.5-2.0 kg) and to determine tissue concentration of the drug following oral administration (10 mg/kg) for 5 days. Drug concentration in tissue was determined using High Performance Liquid Chromatography (HPLC). Repeated oral administration of levofloxacin in layer birds was found safe based on evaluation of haematological (Hb, PCV, TLC and DLC), blood biochemical (AST, ALT, AKP, ACP, LDH, BUN, Serum total protein, Serum albumin, Serum Creatinine, Blood glucose and Total bilirubin) and histopathology of liver, kidney and joint cartilage. Levofloxacin could not be detected in body tissues (liver and skeletal muscle) at 12 hours after the last administration.