prolonged QT interval and thioridazine
Last reviewed 01/2018
The Committee on Safety of Medicines (CSM) has advised that the use of thioridazine should be restricted to the second line treatment of schizophrenia in adults:
- this is after the CSM considered the evidence relating to the rare but serious cardiotoxicity (QTc interval prolongation and ventricular arrhythmias)
- the balance of risks and benefits is unfavourable for its previous indications (agitation and restlessness in the elderly, anxiety, violent and dangerously impulsive behaviour, mania/hypomania, and behavioural disorders and epilepsy in children)
- thioridazine treatment should be supervised by a consultant
The CSM advice notes that clinicians should re-evaluate their patients treated with thioridazine, in light of the new evidence. If thioridazine is discontinued then a gradual reduction in dose over one or two weeks is recommended.
The summary of product characteristics should be consulted before prescribing this drug.
- (1) Message from Professor Alasdair Breckenridge, Chairman, Committee on Safety of Medicines, Thioridazine: restricted indications and new warnings on cardiotoxicity, 11/12/00.
precautions/warnings concerning use of thioridazine