Evaluation of serum sodium changes in tricyclic antidepressants toxicity and its correlation with electrocardiography, serum pH, and toxicity severity

Background: Tricyclic antidepressants (TCAs) is a group of drugs used for the depression treatment. One of the effects of these drugs is Na (sodium) channel blocking ability causing cardiac complications such as ventricular tachycardia and Torsades de pointes Arrhythmia. Sodium bicarbonate is used for treatment of these complications which may have some effect on serum sodium levels. Considering no specific research on Na changes on these patients, the serum Na changes and its correlation with ECG changes, serum pH, and TCA toxicity severity were evaluated. Materials and Methods: A prospective descriptive-analytic cross-sectional study was done on TCA-poisoning patients who were admitted in Noor hospital in Esfahan in last 2 years. Serum sodium levels, ECG changes, and TCA severity toxicity of 92 patients were evaluated five times during first 24 h of admission. Results: A total of 92 patients were studied. The most common symptoms were conscious level changes (81.52%) and mydriasis (64.1%). Based on toxicity severity by these symptoms the patients were classified into three groups: 12% of the patients had mild toxicity, 50% moderate, and 38% severe toxicity. There were no significant differences in mean serum Na during the time. There was not found any correlation between serum Na level, and serum pH, ECG, and toxicity severity. Conclusions: Using sodium bicarbonate in TCA-poisoning cases does not change the serum Na levels significantly