Therapeutic effect of phenylbutazone on experimental acute Escherichia coli endotoxemia in ponies.

Phenylbutazone (PBZ), a classic anti-inflammatory and prostaglandin-synthesis inhibitor drug, was used to determine the role of prostaglandins and other mediators on the development and perpetuation of the response to intraperitoneal Escherichia coli endotoxin administration. The PBZ (15 mg/kg of body weight) was administered IV 30 minutes after endotoxin administration and was repeated later at 6 and 12 hours at a dose of 10 mg/kg. A variety of evaluation measurements (hematologic, blood glucose, pyruvate, lactate and fibrinogen, serum beta-glucuronidase, prothrombin time, blood gases, hepatic glycogen, plasma esterase, capillary refill time, and rectal temperature) were utilized. Marked alterations were noted for all evaluators following endotoxin administration except for blood fibrinogen, prothrombin time, and plasma esterase activity. The PBZ therapy blocked the hemoconcentration, hyperglycemia, increased blood lactate, decreased bicarbonate, decreased blood pH, pyrexia, and prolonged capillary refill time responses associated with endotoxin administration. Despite the significant blocking effects of PBZ on endotoxin responses, the eventual survival rate was unaffected in these experiments.