Cephalexin in ponies: a preliminary investigation

Area of Science:

• Veterinary Pharmacology
• Equine Medicine
• Antimicrobial Agents

Background:

• Cephalexin is a widely used antibiotic in veterinary medicine.
• Understanding its pharmacokinetic profile in ponies is crucial for effective treatment protocols.
• Limited data exists on cephalexin's intramuscular administration and absorption in equids.

Purpose of the Study:

• To evaluate the tolerance and pharmacokinetics of a single intramuscular dose of cephalexin in ponies.
• To determine the absorption rate, peak plasma concentration, and duration of effective antimicrobial levels.
• To establish a basis for therapeutic dosing recommendations in equine patients.

Main Methods:

• Six healthy ponies received a single intramuscular injection of cephalexin at a dose of 7 mg/kg.
• Injection site reactions were monitored.
• Plasma samples were collected at various time points post-administration.
• Cephalexin concentrations in plasma were quantified using a validated analytical method.

Main Results:

• The intramuscular administration of cephalexin was well tolerated by all ponies.
• No adverse reactions were observed at the injection sites.
• Cephalexin was rapidly absorbed, achieving a mean peak plasma concentration of 6.77 µg/ml at a mean time of 1.41 hours.
• Plasma concentrations remained above 2.0 µg/ml for 3.8 hours and above 0.5 µg/ml for 9.8 hours.

Conclusions:

• A single intramuscular dose of cephalexin at 7 mg/kg is safe and well-tolerated in ponies.
• The drug exhibits favorable pharmacokinetic properties, including rapid absorption and sustained plasma concentrations.
• These findings support the potential use of intramuscular cephalexin for treating susceptible bacterial infections in ponies.