Purpura and bleeding due to calcium-channel blockers: an underestimated problem? Case reports and a pilot study

Summary Background. Surgical bleeding and occasionally purpura due to calcium‐channel blockers have been described. Aim. To present cases in whom purpura or internal bleeding due to calcium‐channel blockers was a presenting feature, including one subject with drug‐induced haematuria and haematospermia due to amlodipine and one with the Rumpel–Leede sign. Further support for a true association was sought in a pilot study using Hess testing to provoke purpuric skin lesions. Methods. Four representative cases presenting due to purpura or bleeding are described, all of whom had an abnormal Hess test. A further 19 patients taking calcium‐channel blockers and 13 control subjects were also tested. Results. Of 19 patients on calcium‐channel blockers, 16 had either abnormal Hess results (n = 13) or marked acral purpura (n = 3) after a Hess test procedure. A similar abnormal response, of milder degree, occurred in only 2 of 13 control subjects. Conclusions. The high frequency of purpura shown in this study, whether spontaneous or provoked, suggests that this is a pharmacological class effect rather than idiosyncratic. Purpura in patients taking these drugs may be a clue to diagnosis of internal or postsurgical bleeding. We conclude that purpura related to calcium‐channel antagonists is probably underestimated, but further studies are needed to identify the mechanism by which this occurs.