Pharmacokinetics of an extended-release theophylline product in cats.
OBJECTIVE
To evaluate the pharmacokinetics of a brand of extended-release theophylline tablets and capsules in healthy cats.


METHODS
Randomized 3-way crossover study.


METHODS
6 healthy cats.


METHODS
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
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.
Guenther-Yenke
Christine L
CL
Wheat Ridge Veterinary Specialists, Wheat Ridge Animal Hospital, 3695 Kipling St, Wheat Ridge, CO 80033, USA.
McKiernan
Brendan C
BC
Papich
Mark G
MG
Powell
Elizabeth
E
D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D001993:Bronchodilator Agents / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D002214:Capsules; D002415:Cats / Q000097:blood / Q000378:metabolism* / Q000652:urine; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D007275:Injections, Intravenous / Q000662:veterinary; D013607:Tablets; D013806:Theophylline / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine
D001993:Bronchodilator Agents; D002214:Capsules; D003692:Delayed-Action Preparations; D013607:Tablets; D013806:Theophylline