Thromboembolism in patients on thalidomide for myeloma

Seven cases of thromboembolism were found amongst 23 patients treated with thalidomide for myeloma over a total of 141.5 patient treatment months. Five thromboembolic events were venous (two severe) and two arterial. A historical control of 18 similar patients not given thalidomide had one thromboembolism over 289 months. We found no underlying thrombophilic tendency in the affected patients. We suggest that the thalidomide may predispose to thromboembolism at even lower doses than previously reported (mean dose 150 mg). The two most severe thromboses occurred on 100 mg thalidomide alone, not associated with chemotherapy or glucocorticoids. We raise the possibility that arterial thromboembolism may also occur in association with thalidomide. Some patients continued thalidomide after the event, together with warfarin, with no further thromboembolism.