ASPIRIN, DIPYRIDAMOLE, HEPARIN & ANTICOAGULANTS INCREASE RISK OF HAEMORRHAGE ALTHOUGH ALL ARE USED IN COMBINATION SOMETIMES. OTHER DRUGS WHICH AFFECT THE PLATELET FUNCTION DO LIKEWISE, INCLUDING SULPHONAMIDES, ALLOPURINAL, DEXTRANS, QUINIDINE, SEX HORMONES, TETRACYCLINES, VALPROIC ACID & SOME ESSENTIAL OILS.