Pharmacokinetics of ketoprofen in healthy foals less than twenty-four hours old.

The research investigates the body’s response to the delivery of ketoprofen to infant horses who are less than 24 hours old, and highlights the necessary adjustment of the medication’s dosage compared to that administered to adult horses due to differences in the body’s pharmacokinetic attributes.

Methods and Procedures

• The experimental subjects were 6 healthy foals, including 1 male and 5 females all aged under 24 hours.
• The horse medicine, ketoprofen, was injected intravenously (i.v.) using a dosage of 2.2 mg/kg of the foal’s weight.
• High-performance liquid chromatography was used to analyze the concentration of ketoprofen in the foal’s blood plasma.
• Blood samples were taken from the foals at pre-determined intervals over a 48 hour period, from which plasma was separated and stored at -70 C to be later analyzed.
• Standard pharmacokinetic techniques were used to investigate the ‘concentration versus time’ profiles.
• Analyses were conducted using one, two, and three compartment models, and the unsuitability of each was judged using Akaike’s information criterion analysis.

Findings

• The best fit for the data was found using a two-compartment open model.
• Clearance levels (adjusted for body weight) were significantly lower than those recorded for adult horses, while the volume of distribution (also adjusted for body weight) was larger.
• The half-life of ketoprofen in the plasma of healthy foals was found to be approximately 4.3 hours.

Conclusions and Recommendations

• Different factors including dehydration and sepsis must be considered on a case-by-case basis.
• The amount of ketoprofen given to foals should not match the dosage provided to adult horses due to significant differences in the body’s pharmacokinetic attributes, such as clearance rates and volume of distribution.
• To achieve similar therapeutic results as in adults, foals’ drug dosage should be increased by up to 1.5 times. To prevent toxicity, however, dose intervals should be extended according to the clinical response.