Long-term oral anticoagulant therapy

Oral anticoagulants have been widely used for over 40 years and since their introduction their use has fluctuated as evidence for efficacy has been challenged, as new indications have been introduced and as the control of unwanted effect has improved. Most hospitals have large anticoagulant clinics and in this country alone over two million tests of anticoagulant control were performed in 1982. Many patients are treated indefinitely and some will have started therapy when ideas about permanent treatment were quite different. The indications for starting and stopping therapy need continuous review.