[Which anticoagulants?].

Anticoagulants used in daily practice include low molecular weight heparins (LMWHs) and vitamin K antagonists. LMWHs are easy to use by means of adjusted subcutaneous injection, weight-adjusted in case of therapeutic indications. LMWHs are cleared principally by the renal route and are contra-indicated in case of renal insufficiency. The LMWHs are indicated in the prevention and treatment of venous thromboembolism. They can be safely administered in pregnancy and during breast-feeding. Oral anticoagulant therapy is the treatment of choice for long term management. Vitamin K antagonists are contra-indicated in pregnancy, especially between the 6th and the 12th week of gestation (risk of embryopathy); they can be given during breast-feeding subject to some precaution. Main indications for vitamin K antagonists are long term treatment of venous thromboembolism, prevention of both arterial and venous thrombo-embolic events associated with the antiphospholipid--antibody syndrome, prevention of systemic embolism associated with heart valves and, rheumatic mitral valve disease and, atrial fibrillation and, acute myocardial infarction.