Pharmacokinetic Studies of Orally Administered Cefpodoxime Proxetil in Alcids
Abstract
Cephalosporin antibiotics have been used empirically in avian species and have appeared to be safe and effective against infection by gram-negative bacteria and staphylococci. Seabirds can be given antibiotics hidden in their food without stressful handling, but absorption rates, half life, rates of excretion, and the possibility of other metabolic effects have not been determined in these species.
Twenty-three alcids (tufted puffins [Fratercula cirrhata] and horned puffins [Fratercula corniculata]) were fed a single oral dose of cefpodoxime proxetil at 10 mg/kg in gelatin capsules hidden in fish. A maximum of three blood samples was collected from each bird at staggered intervals resulting in collection of 3 to 4 blood samples at multiple time units between 0.5 and 48 hours after dosing.
Pre- and post-dose plasma samples were analyzed using HPLC to measure cefpodoxime. Drug levels were highest during the initial 1 to 2 hours after oral dosing and declined to less than detectable within six hours. Failure to achieve long-term therapeutic concentrations in these birds may be due to poor oral absorption, poor conversion to the active form, rapid elimination, or a combination of these factors.
Safety of cefpodoxime was assessed by analyzing whole blood and plasma collected before and after dosing. There was no significant change in blood cell parameters or clinical chemistry values, but the short duration of therapeutic blood levels indicates that once-daily dosing is unlikely to provide clinical benefit in controlling infections.
Acknowledgements
Funding for this project was provided by a grant from the Oiled Wildlife Care Network. Major assistance was provided by the Alaska SeaLife Center Avian Department staff. All animal handling was conducted under procedures approved by the ASLC Institutional Animal Care and Use Committee.