Effects of high ticlopidine doses on platelet function in acute coronary syndrome patients.
BACKGROUND
We investigated whether higher doses of ticlopidine combined with acetylsalicylic acid would allow a faster inhibition of platelet activation and aggregation in patients with acute coronary syndromes potentially undergoing percutaneous coronary intervention with stent placement.


METHODS
Seventeen patients presenting with acute coronary syndromes and candidates for possible percutaneous coronary intervention were randomized to ticlopidine 250 mg or 500 mg twice daily for 5 days. Platelet aggregation and activation were assessed at baseline before the first dose and daily for 5 days.


RESULTS
After 2 days of treatment, 500 mg twice daily of ticlopidine produced a significantly larger reduction in platelet activation and aggregation than 250 mg twice daily. Mean platelet activation was 17.6 +/- 3.3% lower with 500 mg twice daily from days 3 to 6 (P < or = 0.05). Mean platelet aggregation was 16.9 +/- 0.6% lower in patients treated with the higher dose on days 3 through 6 when compared with those on ticlopidine 250 mg twice daily (P < 0.05).


CONCLUSIONS
A faster and stronger inhibition of platelet activation and aggregation is obtained when 500 mg twice daily of ticlopidine is administered daily in combination with acetylsalicylic acid in patients with acute coronary syndromes.
Bélanger
Patrick
P
Research Center, Hôpital du Sacré-Coeur de Montréal, and Faculty of Pharmacy, Université de Montréal, Montréal, Quebec, Canada.
Palisaitis
Donald A
DA
Diodati
Jean G
JG
Pharand
Chantal
C
D001241:Aspirin / Q000627:therapeutic use; D003327:Coronary Disease / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D013988:Ticlopidine / Q000008:administration & dosage / Q000627:therapeutic use*
D010975:Platelet Aggregation Inhibitors; D013988:Ticlopidine; D001241:Aspirin