QTc interval prolongation is considered a risk factor for fatal polymorphic ventricular tachycardia, which can result in sudden cardiac death. Most psychotropic drugs have a dose-dependent potential to prolong the QTc interval. However, other factors require appropriate consideration, including: age; gender; other medications; electrolyte abnormalities; severe comorbid conditions, such as co-occurring alcohol or substances abuse/dependence.

The objective was to study the potential mediating roles of alcohol/substances abuse on QTc prolongation.

The Italian research group STAR Network, in collaboration with the Young Italian Psychiatrists Association, aimed to evaluate the frequency of QTc interval prolongation in a sample of patients under treatment with psychotropic drugs through a cross-sectional national survey.

A sample of 2411 unselected patients were enrolled after performing an ECG during the recruitment period. Sociodemographic and clinical characteristics were collected from medical records. Collected data underwent statistical analysis.

A total of 11.2% of patients reported alcohol abuse, and only 8.9% psychotropic substances. According to the threshold, less than 20% of patients had a borderline value of QTc, and 1% a pathological value. Patients with co-occurring alcohol misuse and drug abuse were more likely to have longer QTc interval.

The present study describes the frequency of QTc prolongation in real-world clinical practice. Before prescribing a psychotropic drug, the physician should carefully assess its risks and benefits to avoid this type of adverse reaction, particularly when additional risk factors are present. The potential role of alcohol and substances on QTc length could be particularly useful in emergency settings.

The authors have not supplied their declaration of competing interest.