The Role of Dihydroergotamine in the Prophylaxis of Postoperative Deep Vein Thrombosis

In randomly allocated trials, the prophylactic efficacy of DHE and a combination of DHE with heparin was investigated in 200 consecutive patients. Of 100 patients undergoing major surgery, 50 received 0.5 mgm. of DHE every 12 hours and 50 received 50000 units of heparin every 8 hours. The frequency of DVT, determined by the 125_I-fibrinogen uptake test, was 20% in those receiving DHE compared with 4% in those receiving heparin, the difference being statistically significant (p 0.05).

Of 100 patients undergoing total hip replacement arthroplasty, 50 received 5000 IU of heparin every 8 hours, and 50 received heparin according to the same regimen, together with 0.5 mgm. of DHE. DVT was detected by the 125_I-fibrinogen test and venography. Twenty-six (52%) patients in the heparin group developed DVT, compared with 1– (20%) who received the combination; the difference in the incidence of thrombosis between the two groups was statistically highly significant (p 0.005).

The effect of DHE on calf muscle blood flow was determined using Xenon¹³³. There was significant increase in mean muscle blood flow 2 hours after the administration of 0.5 mgm. of DHE subcutaneously (p 0.05).

It is concluded that a combination of DHE and heparin is more effectively than heparin alone in preventing postoperative DVT.