HEPARINS: For unfractionated heparins, certain studies have demonstrated increased hemorrhage rates correlated with age and with renal function. Subcutaneous injections every 12 hours are as effective and less uncomfortable for the patient than continuous intravenous infusions. Low-molecular-weight heparins are currently contraindicated for curative treatment and their use is not recommended for prevention when the creatinine clearance is below 30 ml/min. OTHER ANTICOAGULANTS: The dosage of sodium daparanoid should be adapted to the renal function with regular surveillance of anti Xa activity. With hirudin, there is a risk of product accumulation in case of renal failure. For oral anticoagulants the relationship between old age and the frequency of hemorrhagic complications is still a subject of debate. ORAL ANTICOAGULANTS: The starting dosage should be reduced to one-half or one-quarter of the usual dose. The INR should be measured regularly, particularly since elderly subjects are highly susceptible to wide variations in INR irrespective of the cause. It is also advisable to carefully determine appropriate situations when oral coagulants should be used.