[Ventricular tachyarrhythmia as a side effect of pharmacotherapy].

Ventricular tachyarrhythmia is a severe and life-threatening potential side effect of pharmacotherapy. Substances with proarrhythmic potential belong to various groups of medication. Apart from antiarrhythmic agents, especially antibiotics and psychiatric drugs are worth mentioning owing to their broad application. Interaction with cardiac potassium channels is the most important reason for drug-induced ventricular tachyarrhythmia. Over 20 years of research in animal models and clinical studies have uncovered the underlying mechanisms. Findings in this field of research have also made a contribution to the understanding of genetic long QT syndromes. Clinical concerns that take drug interactions into account have been neglected due to the mechanistic research approach. For daily clinical practice, combination therapy of several potentially arrhythmogenic drugs is of predominant concern especially in situations when the therapeutic regime is changing such as admission to the hospital, admission to an intensive care unit or consultation of a new specialist. Especially in these situations, considerations about the arrhythmogenic potential of additionally administered drugs should be paid explicit attention. Additional concern should be paid to the fact that several proarrhythmogenic agents are metabolized over single pathways and are therefore prone to drug interactions that can severely raise the drug concentration and as a result arrhythmogenic potential.