Key Points
- To determine the prevalence of drug-induced long QT interval at hospital admission among adult psychiatric inpatients and identify the associated clinical risk factors.
- Reviewed admission ECG recordings collected over a 5-year period from 6,790 adult psychiatric inpatients at a public psychiatric hospital.
- Identified drug-induced long QT cases (heart-rate corrected QT ≥500 ms with certain or probable drug imputability; N=62) and compared them against patients with normal ECG findings (N=143).
- Among 6,790 inpatients, 27.3% had abnormal ECGs, 1.6% had long QT, and 0.9% met criteria for drug-induced long QT; 5 sudden cardiac deaths and 7 torsade de pointes events occurred.
- Drug-induced long QT was significantly associated with hypokalemia, abnormal T wave morphology, HCV, HIV, and treatment with haloperidol, clotiapine, phenothiazines, or citalopram (including escitalopram) after multivariable adjustment.
- Receiver operating characteristic curve analysis revealed that 85.5% of drug-induced long QT patients had two or more clinical risk factors, whereas 81.1% of patients with normal ECGs had fewer than two factors.
Structured PICO
What is the prevalence of drug-induced long QT and its associated factors among adult psychiatric inpatients?
PPopulation6,790 adult psychiatric inpatients admitted to a public psychiatric hospital over a 5-year period. A subgroup analysis compared 62 patients with drug-induced long QT to 143 patients with normal ECG.
IInterventionPsychotropic drug administration (including haloperidol, sertindole, clotiapine, phenothiazines, fluoxetine, citalopram, and methadone)
CComparatorPatients with normal ECG (N=143)
OOutcomePrevalence of drug-induced long QT (heart-rate corrected QT ≥500 ms and certain or probable drug imputability) and associated factorssafety
Specific psychotropic drugs, particularly haloperidol, clotiapine, phenothiazines, and citalopram, significantly increase the risk of drug-induced long QT in psychiatric inpatients, especially in the presence of hypokalemia, HCV, HIV, or abnormal T wave morphology.