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

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.