The influences of depression and venlafaxine use at therapeutic doses on atrial conduction

The Effect of Venlafaxine on Electrocardiogram Intervals During Treatment for Depression in Older Adults

PURPOSE/BACKGROUND

Venlafaxine is a commonly used antidepressant with both serotonergic and noradrenergic activity. There are concerns that it may prolong the corrected QT interval (QTc), and older adults may be at higher risk for this adverse effect, especially at higher dosages of the medication.

METHODS/PROCEDURES

In this secondary analysis of a prospective clinical trial, we measured changes in QTc and other electrocardiogram (ECG) parameters in 169 adults 60 years or older with a major depressive disorder treated acutely with venlafaxine extended release up to 300 mg daily. We examined the relationship of venlafaxine dosage and ECG parameters, as well as the relationship between serum levels of venlafaxine and ECG parameters.

FINDINGS/RESULTS

Venlafaxine exposure was not associated with an increase in QTc. Heart rate increased with venlafaxine treatment, whereas the PR interval shortened, and QRS width did not change significantly. The QTc change from baseline was not associated with venlafaxine dosages or serum concentrations. Age, sex, cardiovascular comorbidities, and depression remission status did not predict changes in QTc with venlafaxine.

IMPLICATIONS/CONCLUSIONS

Venlafaxine treatment did not prolong QTc or other ECG parameters, even in high dosages in older depressed adults. These findings indicate that venlafaxine does not significantly affect cardiac conduction in most older patients.

Risk of QT/QTc Prolongation Among Newer Non-SSRI Antidepressants

Objective: To review QT prolongation potential with newer nonselective serotonin reuptake inhibitor (non-SSRI) antidepressants. Data Sources: A PubMed literature search was performed from 1982 through June 16, 2014. Search terms included bupropion, desvenlafaxine, duloxetine, levomilnacipran, mirtazapine, venlafaxine, and vilazodone in combination with each of the following terms: cardiac toxicity, QTc prolongation, QT prolongation, torsades de pointes, and TdP. Study Selection and Data Extraction: English-language human studies, case reports, package inserts, manufacturer electronic communications, and ArizonaCert database were utilized. Data Synthesis: Rare QT prolongation has been reported with venlafaxine at therapeutic doses and in overdose. Bupropion has also been linked to QT prolongation in overdose situations. In elderly patients with a variety of high-risk comorbidities, mirtazapine did demonstrate higher odds of sudden cardiac death and ventricular arrhythmias when compared with paroxetine. Largely because of a lack of available data, existing studies fail to demonstrate QT prolongation with desvenlafaxine, duloxetine, levomilnacipran, and vilazodone. Conclusion: Based on the current literature, risk of QT/QTc prolongation with the majority of newer non-SSRI antidepressants at therapeutic doses is low. The highest risk for QT prolongation appears to exist in overdose situations with venlafaxine and bupropion. Given the few to nonexistent controlled studies and confounding variables present in case reports, it is difficult to draw conclusions on QT prolongation risk with many of the newer non-SSRI antidepressants.

Patterns of cardiorespiratory coordination in young women with recurrent major depressive disorder treated with escitalopram or venlafaxine

Evidence from previous studies suggests autonomic dysregulation in patients with major depressive disorder (MDD). Antidepressant treatment may also affect central autonomic function. We investigated whether the type of antidepressant might be associated with the pattern of cardiorespiratory coordination in non-depressed women with recurrent MDD. Resting electrocardiograms and respiratory signals were simultaneously recorded from 38 euthymic women with recurrent MDD who were treated with either escitalopram (n=19) or venlafaxine (n=19) monotherapy and from 38 healthy women. Linear measures of heart rate variability were extracted to assess cardiac autonomic control. Sample entropy (SampEn) was computed to assess the complexity of heart rate and respiratory signals, and cross-SampEn was calculated to measure the nonlinear interaction of both signals. Significant decreases in the cardiovagal tone and cardiorespiratory coupling of women with recurrent MDD receiving venlafaxine, and tendencies toward lower cardiovagal tone and cardiorespiratory coupling in women with recurrent MDD receiving escitalopram were observed when compared with healthy controls. Effect sizes for these differences were large between women receiving venlafaxine and healthy controls. We found a positive association between cardiorespiratory decoupling and venlafaxine dose. Norepinephrine-enhancement, within a therapeutic dose range, seems to be closely associated with decreased vagal tone and reduced nonlinear coupling between heart rate and respiration in euthymic women with recurrent MDD. However, the effects of serotonin enhancement on cardiovagal tone should be considered. Our results suggest that the pharmacodynamic properties of antidepressants may affect autonomic regulation of women with recurrent MDD even in euthymic state.