Effects of low intensity antithrombotic regimes on the haemoglobin level.

The effects on the haemoglobin level of low dose aspirin and of low intensity oral anticoagulation with warfarin separately and in combination have been established in men aged between 45 and 69 at high risk of ischaemic heart disease. The findings confirm that combined treatment with warfarin and aspirin (WA) leads to a clear excess of minor bleeding episodes over warfarin alone (W) or aspirin alone (A). Each separate treatment on its own (either W or A) leads to an increase in these episodes compared with those on placebo (P) treatment. However, neither combined treatment (WA) nor the separate treatments (W or A) cause a fall in haemoglobin levels over a period of up to two years.