Calcium channel antagonist exposures reported to the Poisons Information Center Erfurt.

BACKGROUND

We investigated the toxicity profile of the three main groups of calcium channel antagonists (CCA) and compared mixed CCA exposures (CCA plus another drug) with mono CCA exposures.

METHODS

All CCA exposures reported to the PIC Erfurt from 2000 to 2009 were analyzed retrospectively.

RESULTS

In total, 727 (230 mono and 497 mixed) CCA exposures were registered. Although CCA exposures increased almost twofold from 56 in 2000 to 108 in 2009 their relative frequency to all exposures remained constant. The five CCAs most frequently involved in exposures were the five most frequently prescribed ones in Germany over the same period. In mono and mixed CCA exposures, none or minor symptoms were most often seen with dihydropyridines (mono: 84.7%; mixed: 68.0%) followed by diltiazem (mono: 71.4%; mixed: 62.5%) and verapamil (mono: 57.1%; mixed: 50.0%). Highest rates of moderate (mono: 8.6%: mixed: 20.2%) and severe symptoms (mono: 18.6%; mixed: 23.7%) were observed after verapamil ingestions. Death most frequently occurred with diltiazem (mono: 28.6%; mixed: 12.5%). Rates of moderate symptoms were higher in mixed (13.3%) than in mono CCA exposures (4.8%). No distinct differences were seen regarding the relative frequency of none or minor symptoms, severe symptoms, and death between mono and mixed CCA exposures.

CONCLUSION

Exposures to verapamil more often resulted in moderate and severe symptoms than with dihydropyridines. Death mainly occurred with diltiazem. Moderate symptoms were more frequent in mixed than in mono CCA exposures. The frequency of CCAs involved in exposure was related to their prescription.