B-Type Natriuretic Peptide and Troponin I as Possible Predictive Biomarkers for Cardiotoxicity Induced By Tricyclic Antidepressants and Antipsychotics Overdose

Overdose by tricyclic antidepressants and antipsychotic drugs can lead to potentially lifethreatening cardiotoxicity. In clinical medicine, B-type natriuretic peptide (BNP) and cardiac troponin I (cTnI) are used as serum biomarkers in the diagnosis of cardiac affection. Aim:  The study aimed to investigate the utility of  BNP and troponin I as early predictors for TCA and antipsychotic drug -induced cardiotoxicity and  correlation with severity of poisoning. Method:  The study enrolled 45 patients admitted in ICU of Poison Control Center of Ain Shams University Hospitals (PCC-ASUH) with history of tricyclic antidepressants (TCA) and /or antipsychotics overdose. Collected data included sociodemographic data,  manner of exposure, clinical variables, ECG changes, Poison Severity Score (PSS), serum levels of BNP and cTnI. Duration of ICU and hospital stay, and outcome were also noted. Results:  In contrast to cTnI level, BNP level was significantly higher in cardiotoxicity group. Mean BNP level correlated with ECG and blood pressure changes. Biomarkers levels were nonsignificantly correlated with PSS, total hospital stay &ICU stay. PSS had low sensitivity and accuracy for prediction of cardiotoxicity. Both BNP and cTnI showed at specific cut off point showed 100% specificity with sensitivity of 53.13% & 25.0% respectively Conclusion:  Although unsuitable for screening purposes, BNP surpassed cTnI as a useful tool for the diagnosis of cardiotoxicity due to overdose by tricyclic antidepressants and antipsychotic drugs