Gentamicin dosage in foals aged one month and three months

Area of Science:

• Veterinary Pharmacology
• Equine Pharmacokinetics
• Antimicrobial Drug Dosing

Background:

• Gentamicin is a crucial antibiotic for treating bacterial infections in foals.
• Understanding its absorption and disposition kinetics is vital for effective treatment protocols.

Purpose of the Study:

• To compare the absorption and disposition kinetics of gentamicin in one- and three-month-old foals at different dosage levels.
• To establish an optimal and safe dosage regimen for gentamicin in foals.

Main Methods:

• Intramuscular (im) injection of gentamicin at 2 and 4 mg/kg bodyweight (bwt) in foals of different ages.
• Measurement of serum gentamicin concentrations over time to determine pharmacokinetic parameters.
• Assessment of renal excretion and minimum inhibitory concentrations (MICs) against relevant bacterial isolates.

Main Results:

• Rapid absorption of gentamicin following im injection, with peak serum concentrations at 30 minutes for the 2 mg/kg bwt dose.
• Similar gentamicin half-life in one- and three-month-old foals, independent of dose.
• No apparent deficiency in renal excretion of gentamicin in one-month-old foals.
• MICs for gentamicin against Corynebacterium equi and other equine isolates were below 0.195 microgram/ml.

Conclusions:

• A gentamicin dose of 2 mg/kg bwt administered intramuscularly every 8 to 12 hours is recommended for treating systemic infections in foals caused by susceptible microorganisms.
• The dosage regimen should be adjusted based on infection severity.
• Gentamicin exhibits favorable pharmacokinetic properties for use in young foals.