Ticlopidine activity on platelet function in patients with enhanced platelet aggregation. A short-term crossover...

Area of Science:

• Pharmacology
• Hematology
• Cardiovascular Research

Background:

• Platelet aggregation plays a crucial role in thrombosis.
• Understanding agents that modulate platelet function is vital for cardiovascular disease prevention.
• Ticlopidine is an antiplatelet drug with a known mechanism of action.

Purpose of the Study:

• To investigate the effects of ticlopidine on platelet function in patients with enhanced platelet aggregation.
• To assess the in vivo and in vitro antiplatelet activity of ticlopidine.
• To elucidate the mechanism underlying ticlopidine's antiaggregating effects.

Main Methods:

• Single-blind crossover study involving 16 patients.
• Administration of ticlopidine (250 mg t.i.d.) or placebo.
• Assessment of bleeding time, platelet aggregation (in vivo and in vitro), beta-thromboglobulin levels, PGI2 inhibition, and thromboxane B2 (TxB2) production.

Main Results:

• Ticlopidine significantly lengthened bleeding time.
• Significant inhibition of platelet aggregation was observed during ticlopidine treatment.
• Beta-thromboglobulin concentration decreased, and conversion of arachidonic acid to TxB2 was reduced.
• Platelet TxB2 production after thrombin stimulation remained unchanged.

Conclusions:

• Ticlopidine is a potent in vivo antiaggregating agent.
• Its antiplatelet activity appears to stem from interference with platelet membrane receptors and functions.
• These findings support ticlopidine's role in managing conditions associated with heightened platelet activity.