Antidepressant drug adherence linked to reduced MI risk
MedWire News: Results from a large US study indicate that adherence to 12 weeks of continuous antidepressant pharmacotherapy may reduce the risk for myocardial infarction (MI) in depressed patients with no history of cardiac disease.
"This finding was consistent across individual drugs, drug classes, and outcomes," remark Jeffrey Scherrer (Washington University School of Medicine, St Louis, Missouri) and team.
"Although the mechanism for this association remains uncertain, it is possible that compliance with pharmacotherapy for depression reflects compliance with cardiovascular (CV) medications," suggest the researchers.
The findings arise from an analysis of the 7-year outcomes of 93,653 clinically depressed US veterans with a mean age of 51.5 years.
Of these patients, 78.7% received antidepressants for 12 or more continuous weeks, 8.4% received no antidepressants, and 12.9% received 1-11 weeks of antidepressant therapy.
The patients receiving antidepressants for at least 12 weeks were treated with selective serotonin reuptake inhibitors (SSRIs; n=58,714), serotonin-norepinephrine reuptake inhibitors (SNRIs; n=21,330), tricyclic antidepressants (TCAs; n=9950), or an unspecified class of antidepressant ("other"; n=31,468).During the 7-year follow-up period, only 4% of all patients had a MI, report Scherrer et al in the American Journal of Medicine.
Analysis revealed a significantly lower MI risk after 12 weeks treatment with any antidepressant class compared with no antidepressant treatment or antidepressant treatment lasting less than 12 weeks.
Specifically, this risk was reduced by 52% among patients treated with SSRIs, 65% in those treated with SNRIs, 61% in those treated with TCAs, and by 59% among patients who received "other" forms of antidepressant pharmacotherapy.
Of note, all-cause mortality risk was also significantly reduced by 34-50% after at least 12 weeks of any antidepressant therapy compared with no antidepressant therapy or antidepressant therapy lasting less than 12 weeks.
The researchers highlight: "The present finding of a reduced risk for MI in TCA users is inconsistent with the literature that has demonstrated cardiotoxic effects of TCAs associated with arrhythmia."
However, Scherrer and team say that this suggests that "the mechanism of effect in the present study leans toward improvement in depression, compliance, or the possibility that patients free of CV disease are not at increased risk when taking TCAs."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Lauretta Ihonor