Older Type of Antidepressants Found to Double Heart Attack Risk
Jan. 26, 2000 (Indianapolis) -- A new study has shown that depressed patients taking an older type of medication called tricyclic antidepressants had twice the risk of having a heart attack as nondepressed people. Patients taking medications from the newer class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs) did not show an increased risk of having a heart attack.
Tricyclic antidepressants -- such as Elavil (amitriptyline), Pamelor (nortriptyline), and Tofranil (imipramine) -- first came onto the market 30-40 years ago and were the mainstay of drug treatment for depression up until the late 1980s, when SSRIs came on the scene. SSRIs -- such as Prozac (fluoxetine), Paxil (paroxetine), and Zoloft (sertraline) -- quickly replaced tricyclics as the medication of choice for depression because they are much safer and generally better tolerated by patients. Since the introduction of SSRIs, there has been an explosion in new drug treatments for depression, leading to several even newer classes of antidepressants.
Over the last two decades, multiple studies have shown a link between depression and heart disease, according to the National Institutes of Health. However, the exact cause for the association has not been known, and researchers have not been able to determine whether treatment for depression would affect this risk.
"At first, we were looking to see if the use of antidepressants as an indicator of depression would be associated with [heart] disease outcomes," says lead study author Hillel W. Cohen, DrPH, during an interview with WebMD. "We found that the overall association of antidepressants to [heart] disease was really particular to the tricyclics and was not seen with the SSRIs." Cohen is a researcher in the department of epidemiology and social medicine at the Albert Einstein College of Medicine in the Bronx, N.Y. The study results are published in the January issue of TheAmerican Journal of Medicine.
Antidepressant users had over twice the risk of heart attack when compared with nonusers. When the investigators looked at the kind of medicine prescribed, the risk of heart attack was still twice as high in users of tricyclics. No association was seen between the use of SSRIs and heart disease.
"The history of [tricyclics] that indicates they should be used with caution -- if at all -- in those patients with [heart] problems is strengthened by this data," says Cohen. "In the past, this concern has only been in people with very specific kinds of problems with their hearts [namely, heart rhythm irregularities]. This data suggests that we may want to expand this caution to include any [heart] disease."
Not everyone is so concerned about the study results, however. "I would tell my patients to not worry about the outcomes of this study," William H. Coryell, MD, professor of psychiatry at the University of Iowa in Iowa City, tells WebMD in an interview seeking objective analysis of the findings. "They could have gotten these results from reasons other than an increased risk for [heart attack] with these drugs. Placement on tricyclics may have been an indication of treatment resistance which, in turn, shares some risk factors with [heart] disease."