[Psychopharmaceuticals and arrhythmias]

Psychoactive drugs have been associated with arrhythmia for 40 years. Torsades de pointes was originally seen in patients with pre-existing heart disease or with intoxication. Now, there is increasing awareness that drugs used for non-antiarrhythmic and non-cardiovascular indications can exert significant effects on repolarisation and may cause ventricular tachycardia. Most of the drugs that prolong the QT-interval incorporate blockade of the potassium channel Ikr in their spectrum. Among psychotrophic drugs the low-potency phenothiazines have most often been implicated, particularly thioridazine. For the high-potency phenothiazines and butyrophenones there are fewer reports on serious arrhythmia. More recently the atypical antipsychotics have been introduced. Although some of them increase the QT-interval considerably arrhythmic events seem to be a very rare problem with the atypical antipsychotics available. Drugs acting as class I antiarrhythmics such as tricyclic antidepressants are not recommended after myocardial infarction. Selective serotonin reuptake inhibitors seem to be safe. Patients with a prolonged QT-interval or patients that experienced Torsade de pointes are at a considerable higher risk upon exposition to a QT-prolonging drug. Drug interactions played a role in many fatalities with QT-prolonging drugs and are important.