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Published on: July 4, 2014
Pharmacokinetics of an extended-release theophylline product in cats
Christine L Guenther-Yenke1, Brendan C McKiernan, Mark G Papich
1Wheat Ridge Veterinary Specialists, Wheat Ridge Animal Hospital, 3695 Kipling St, Wheat Ridge, CO 80033, USA.
Objective:
To evaluate the pharmacokinetics of a brand of extended-release theophylline tablets and capsules in healthy cats.
Design:
Randomized 3-way crossover study.
Animals:
6 healthy cats.
Procedures:
A single dose of aminophylline (10 mg/kg [4.5 mg/lb], IV), a 100-mg extended-release theophylline tablet, or a 125-mg extended-release theophylline capsule was administered to all cats. Plasma samples were collected via preplaced central catheters throughout a 36-hour period. Plasma samples were frozen until analyzed by use of a fluorescence polarization monoclonal immunoassay.
Results:
All cats tolerated drug administration and plasma collection with no adverse effects. Peak concentrations were reached for both orally administered products between 8 and 12 hours after administration. Bioavailability was excellent. Plasma concentrations were within the human therapeutic concentration of 5 to 20 microg/mL.
Conclusions And Clinical Relevance:
Daily administration of the brand of theophylline tablets and capsules used in this study at 15 mg/kg (6.8 mg/lb) and 19 mg/kg (8.6 mg/lb), respectively, maintained plasma concentrations within the desired therapeutic range in healthy cats.
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