Evaluation of antiplatelet effects of ticlopidine in cats.
OBJECTIVE
To determine whether ticlopidine exerts an antiplatelet effect, estimate the pharmacodynamics of ticlopidine, and evaluate any acute adverse effects associated with administration of ticlopidine in cats.


METHODS
8 domestic purpose-bred sexually intact male cats.


METHODS
Ticlopidine was administered orally (50 mg, q 24 h; 100 mg, q 24 h; 200 mg, q 24 h; and 250 mg, q 12 h). Each treatment period consisted of 10 days of drug administration. Platelet aggregation studies with adenosine diphosphate (ADP) and collagen and evaluation of oral mucosal bleeding times (OMBTs) were performed on days 3, 7, and 10 during each drug administration. Serotonin was measured to evaluate secretion at baseline and on day 10 for cats that received the 250-mg dosage.


RESULTS
A significant reduction in platelet aggregation was detected in response to ADP on days 7 and 10 at 100 mg, on day 3 at 200 mg, and on days 3, 7, and 10 at 250 mg. A significant increase in the OMBT and decrease in serotonin release on day 10 at 250 mg was also detected; however, the cats had anorexia and vomiting at the 250-mg dosage.


CONCLUSIONS
Although there was a consistent antiplatelet effect at the 250-mg dosage, there was dose-dependent anorexia and vomiting that we conclude precludes the clinical usefulness of this drug 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
Talbott
Kristen K
KK
Green
Henry W
HW
Ward
Michael P
MP
Calloway
Betsy M
BM
D000244:Adenosine Diphosphate; D000704:Analysis of Variance; D000818:Animals; D000855:Anorexia / Q000139:chemically induced; D002415:Cats / Q000378:metabolism*; D003094:Collagen; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D012701:Serotonin / Q000097:blood; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D014839:Vomiting / Q000139:chemically induced
D010975:Platelet Aggregation Inhibitors; D012701:Serotonin; D000244:Adenosine Diphosphate; D003094:Collagen; D013988:Ticlopidine