You are called to assess a man on a general medical ward who has been admitted due to a chest infection. The medical team are concerned that he may be depressed and have started him on treatment. You are concerned by his QTc interval which measures as 490 msec. Which of the following medications that he is prescribed would be most likely to be contributing to his prolonged QTc?
QTc prolongation
In addition to psychotropic drugs, there are a number of additional risk factors for QTc prolongation to consider.
QTc prolongation is an indicator of risk of torsade de pointes and increased cardiac mortality.
| Risk factors for QTc prolongation |
|---|
| Long QT syndrome Bradycardia Ischaemic heart disease Myocarditis Myocardial infarction Left ventricular hypertrophy Hypokalaemia Hypomagnesaemia Hypocalcaemia Extreme physical exertion Stress or shock Anorexia nervosa Extremes of age (old or young) Female gender |
You should also be aware that a number of non-psychotopic drugs can cause QTc prolongation.
| Class | Examples |
|---|---|
| Antibiotics | Ampicillin Erythromycin |
| Antiarrthythmics | Amiodarone Sotalol |
| Antimalarials | Chloroquine Quinine |
| Others | Methadone Tamoxifen Amantadine |
Above tables adapted from the Maudsley Guidelines.
