Randomized blinded controlled trial of dipyrone as a treatment for pyrexia in horses.

The research study aimed to evaluate the effectiveness and safety of dipyrone in treating pyrexia (fever), in horses affected by various diseases. The study found that dipyrone was effective in controlling pyrexia in a significant number of treated horses with minimal adverse effects.

Research Overview

• The randomized, controlled trial involved 138 horses from 14 veterinary sites across 12 states, all showing symptoms of pyrexia due to various infections. These were diseases that occurred naturally, demonstrating the ‘field conditions’ context of the study.
• The horses were chosen randomly to receive either dipyrone as a treatment or a placebo. The study was divided into two phases, including an effectiveness phase and a safety phase.

Study Design and Procedures

• In the first phase to measure effectiveness, a 3:1 ratio was used to assign horses to receive one dose of dipyrone or an equivalent amount of placebo.
• The measure of effectiveness was based on the dipyrone’s ability to achieve a specified decrease in the horse’s rectal temperature after treatment compared to pretreatment values. This also included a certain temperature threshold being attained six hours post-treatment.
• The horses showing suitable temperature reduction by the indicated time were then entered into the safety study phase. This involved administration of dipyrone on an ‘as-needed basis’, with adjustments made by clinical investigators.
• Through both phases of the study, the horses were closely monitored for any adverse effects.

Study Results and Conclusion

• The results revealed a significant disparity in the treatment response between horses treated with dipyrone and those given the placebo. Seventy-seven percent of dipyrone-treated horses showed an effective response, compared to only nineteen percent of the placebo-treated group.
• Any adversarial events that occurred post-treatment were mild and short-lived. The study found no discernible differences between the groups in terms of gastrointestinal adverse events.
• From these results, the study concludes that dipyrone was safe and highly effective at controlling pyrexia in horses, given a single dosage intravenously. The extent of adverse effects was minimal.