Oral bioavailability of pivampicillin in foals at different ages.

This study explores how oral absorption of the drug pivampicillin varies in foals at different stages of growth, and finds that the absorption is consistent across different ages, making the drug effective when administered orally to foals ranging from 11 days to 4 months old.

Research Methodology and Administration of Ampicillin

• The experiment was conducted on six healthy, 1-month-old foals. The team first administered ampicillin, a type of penicillin, intravenously to these foals at a dosage of 15 mg/kg.
• They then analyzed the plasma disposition of the drug. Plasma disposition describes how the drug is absorbed, distributed, metabolized, and eventually eliminated from the body.
• The mean distribution and elimination half-lives of the drug were calculated as 0.121 hours and 0.624 hours, respectively. Half-life is the time taken for the concentration of the drug to reduce to half in the plasma.
• The volume of distribution, often abbreviated as Vss, was established as 0.334 litres/kg. The volume of distribution is a hypothetical volume that would be necessary to contain the total amount of an administered drug at the same concentration that it is observed in the blood plasma.

Administration and Bioavailability of Pivampicillin

• Following the administration of ampicillin, they administered an oral dosage of pivampicillin, an ester prodrug of ampicillin. The dosage was equivalent, on a molecular basis, to the same 15 mg/kg dosage of ampicillin, which amounts to 19.9 mg/kg of pivampicillin.
• The research team then monitored the foals’ plasma concentration of the medication over a 12-hour period.
• This prodrug was swiftly absorbed across all age groups, reaching peak plasma concentrations of 3.83 to 5.69 micrograms per milliliter one hour after administration.
• The mean bioavailability, which refers to the proportion of the drug that enters the circulation when introduced into the body thereby allowing an active effect, ranged from 39.4 to 52.9%.
• No significant difference in peak plasma concentration or bioavailability was observed between the different age groups, suggesting that the absorption of the drug doesn’t vary significantly with age.

Conclusion

• This study concludes that oral administration of pivampicillin at a dosage rate of 19.9 mg/kg provides satisfactory plasma concentrations in foals of all ages, beginning from 11 days until 4 months.
• This means veterinarians can consider using this dose and administration method when treating foals with conditions that require ampicillin, without worrying about age-specific adjustments.