Pharmacokinetics of imipenem-cilastatin following intravenous administration in healthy adult horses.

This research studied the effects and ideal dosage of the drug imipenem-cilastatin, when administered to healthy adult horses intravenously. Results showed 10-20 mg/kg every 6 hours to be an appropriate dose, with no adverse effects reported.

Study Design

• The study was centered on the drug imipenem-cilastatin, an antibiotic often used in human medicine, but not commonly studied in veterinary usage. The drug was administered to six healthy adult horses via slow intravenous (i.v.) infusion in two separate studies.
• The first study involved a dosage of 10 mg/kg while the second study used a larger dosage of 20 mg/kg. Each animal underwent both dosage schedules, with a 2-week washout period given in between to eliminate any remaining drug from the body.

Sample Collection and Analysis

• To measure the pharmacokinetics of the drug, blood and synovial fluid samples were collected from each horse for up to 6 hours after the completion of the drug infusion. This window of time allowed researchers to track the absorption, distribution, metabolism, and elimination of the administered drug.
• High-Performance Liquid Chromatography (HPLC) was used to measure the concentration of imipenem in all the collected samples. HPLC is a technique in analytical chemistry used to separate, identify, and quantify each component in a mixture.

Results and Conclusion

• Upon analysis, it was revealed that the drug imipenem-cilastatin was well tolerated by all the horses at both tested dosages. There were no adverse effects observed on the horses during the study period or in the 24-hour observation period that followed each study.
• The results also indicated that the pharmacokinetic profiles of imipenem in both the plasma and synovial fluid of the horses were favorable, showing a rapid absorption and an evenly distributed concentration throughout the body. From these findings, the researchers concluded that an appropriate dosage of imipenem for most pathogens would be between 10-20 mg/kg, administered by slow i.v. infusion every 6 hours.