The effects of thioridazine on the QTc interval - cardiovascular safety in a South African setting

QT-prolonging drugs - should they ever be used?

“…1 Thioridazine (see p. 46 of this issue) is such a drug. 2,3 The QT interval in the ECG for most part represents the electrical 'recharging' of the cardiac myocytes after their depolarisation which initiates systole. This interval is not a passive resting period for the cells but an active, highly coordinated orchestration of numerous transmembranous ion channels that open and close in a specific sequence.…”

“…The study reported in this journal confirms that thioridazine is a drug that can have a significant effect on the ECG. 2,5 Clearly, the best option would be to avoid all drugs that have the potential for prolonging QT. Unfortunately, this solution is not always possible: the drugs may be highly effective in treating the condition for which they are marketed, the drugs may be the cheaper alternative, or there may be no similar non-QT-lengthening drug available.…”