Summary:
So-called atypical antipsychotic drugs were introduced into medical practice with the aim of
minimizing disadvantages or adverse effects of conventional antipsychotics. However, possible
occurrences of torsade de pointes type of malignant ventricular tachyarrhythmia are increasingly
discused in relation to their use. The goal of this review is a closer look at the problem, particularly
the explanation of the mechanism of torsade de pointes, its clinical manifestation, and association
with the electrocardiographic QT interval. The review considers the issues of prevention and
current requirements concerning individual drug safety. The occurrence of torsade de pointes
can be better predicted using experimental data at the level of respective ion channel blockade,
by identification of percentage of patients with significant QT interval prolongation (above 500
ms) during the treatment and/or analysis of drug interactions.
No association between torsade de pointes arrhytmias (or sudden death) and the use of olanzapine,
quetiapine, risperidone and ziprasidone has been documented so far, despite certain degree of
QT interval prolongation described following administration of these drugs. It is, however, advisable
to follow certain general preventive measures to minimize potential treatment risks. Given
the potential for malignant arrhytmias in patients with known long QT syndrome and/or in those
with severe left ventricular dysfunction, it seems prudent to consult the use of any antipsychotic
drug in cardiac patient with a cardiologist. On the other hand, no apparent benefit of routine
ECG monitoring prior and after antipsychotic drug administration in non-cardiac patient is to be
anticipated. Last but not least, other adverse effects like orthostatic hypotension due to -receptors
blockade, impairment of lipid or glucose metabolism, and/or unwanted weight gain should
also be considered when antipsychotic drugs are prescribed.
Key words:
atypical antipsychotic drugs, torsade de pointes, sudden death, QT interval.
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