Antiplatelet effects and pharmacodynamics of clopidogrel in cats.
OBJECTIVE
To evaluate antiplatelet effects and pharmacodynamics of clopidogrel in cats.


METHODS
Original study.


METHODS
5 purpose-bred domestic cats.


METHODS
Clopidogrel was administered at dosages of 75 mg, p.o., every 24 hours for 10 days; 37.5 mg, p.o., every 24 hours for 10 days; and 18.75 mg, p.o., every 24 hours for 7 days. In all cats, treatments were administered in this order, with at least 2 weeks between treatments. Platelet aggregation in response to ADP and collagen and oral mucosal bleeding times (OMBTs) were measured before and 3, 7, and 10 days (75 and 37.5 mg) or 7 days (18.75 mg) after initiation of drug administration. Serotonin concentration in plasma following stimulation of platelets with ADP or collagen was measured before and on the last day of drug administration. Platelet aggregation, OMBT, and serotonin concentration were evaluated at various times after drug administration was discontinued to determine when drug effects were lost.


RESULTS
For all 3 dosages, platelet aggregation in response to ADP platelet aggregation in response to collagen, and serotonin concentration were significantly reduced and OMBT was significantly increased at all measurement times during drug administration periods. All values returned to baseline values by 7 days after drug administration was discontinued. No significant differences were identified between doses. None of the cats developed adverse effects associated with drug administration.


CONCLUSIONS
Results suggest that administration of clopidogrel at dosages ranging from 18.75 to 75 mg, p.o., every 24 hours, results in significant antiplatelet effects in cats.
Hogan
Daniel F
DF
Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA.
Andrews
Dina A
DA
Green
Henry W
HW
Talbott
Kristen K
KK
Ward
Michael P
MP
Calloway
Betsy M
BM
D000284:Administration, Oral; D000818:Animals; D002415:Cats / Q000097:blood*; D000077144:Clopidogrel; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule / Q000662:veterinary; D005260:Female; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000494:pharmacology*; D011897:Random Allocation; D012701:Serotonin / Q000097:blood; D013988:Ticlopidine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology*; D016896:Treatment Outcome
D010975:Platelet Aggregation Inhibitors; D012701:Serotonin; D000077144:Clopidogrel; D013988:Ticlopidine