Central depressant effects and toxicity of propofol in chicks

Propofol is an ultra-short acting anesthetic agent. The information on the pharmacological and toxicological effects of propofol in the chicken is rather limited. This study examines the toxicity and pharmaco-behavioral effects of propofol given intraperitoneally in 7-10 day-old chicks. The median effective doses of propofol for the induction of sedation, analgesia to electric stimulation and sleep in the chicks were 1.82, 2.21 and 5.71 mg/kg, respectively. The 24-h median lethal dose of propofol in chicks was 57.22 mg/kg. The therapeutic indices of propofol for sedation, analgesia and sleep were 31.4, 25.9 and 10, respectively. Propofol at 0.5 and 1 mg/kg reduced the locomotor activity and increased the duration of tonic immobility in chicks. Propofol at 2 and 4 mg/kg caused analgesia to electric stimulation as well as analgesia and anti-inflammatory responses against formalin test in chicks. Propofol at 5, 10 and 20 mg/kg induced sleep in chicks for 8.4 to 25 min. Physostigmine shortened the sleep duration of propofol. Data suggest that propofol induces anti-inflammatory action and central nervous system depression in chicks resulting in sedation, analgesia and anesthesia with wide safety margin. These effects could form the basis of further pharmacological and toxicological studies on propofol in the young chick model, and the drug could be safely applied clinically in the chicken.