Ticlopidine

This drug acts by blocking the platelet ADP receptor, which promotes aggregation when activated.

• currently used in the UK, in combination with aspirin, to prevent thrombosis with coronary stents
• 1-2 % incidence of neutropaenia in patients taking ticlopidine
• current evidence suggests that ticlodipine is more effective than aspirin in preventing a stroke in patients who have already had a transient ischaemic attack or previous stroke - however because of ticlodipine's potential side effect of bone marrow suppression, aspirin remains the treatment of choice in secondary prevention (1)
• ticlodipine has uncommon (0.5-3%) but very serious haematological toxicity including neutropaenia, thrombocytopaenia, thrombotic thrombocytopaenia purpura and (very rarely) aplastic anaemia (2); gastrointestinal side effects and rash are common
• ticlopidine is inactive and metabolised to active metabolites in the liver

The summary of product characteristics should be consulted before prescribing this drug.

Reference:

1. Drug and Therapeutics Bulletin (1999), 37 (8), 59-61.
2. Patrano C et al.Platelet-active drugs: the relationships among dose, effectiveness, and side effects. Chest 2001;119:39S-63S