Effects of tocainide, an oral analogue of lidocaine, on thromboembolism after total hip replacement.

In an investigation of deep venous thrombosis and pulmonary embolism, where neither dextran nor other antithrombotic drug prophylaxis was employed, 30 patients subjected to total hip replacement under general anaesthesia were randomly allotted to one of two groups. One group (n=15) received tocainide, an oral analogue of lidocaine, as a means of preventing thromboembolism; the other group (n=15) served as a control. In patients given tocainide the frequency of deep venous thrombosis involving the femoral veins, as observed at phlebography, was 60% (9 of 15), and in the control group 73% (11 of 15). The frequency of pulmonary embolism, as determined by pulmonary perfusion lung scanning, was 20% (3 of 15) in the the tocainide group and 33% (5 of 15) in the control group. It was concluded that tocainide administration had no effect as an antithromboembolic agent. Phlebography revealed that the pattern of deep venous thrombosis after total hip replacement was characterized by a high frequency of isolated thigh vein thrombi in the operated leg, probably related to the surgical procedure. A finding of possible clinical significance was that patients given tocainide had a significantly lower intraoperative blood loss than control patients.