Featured Research

from universities, journals, and other organizations

Antidepressant contribution to arrhythmia risk clarified

Date:
January 29, 2013
Source:
Massachusetts General Hospital
Summary:
An analysis of the medical records of more than 38,000 patients clarifies the contribution of citalopram and other antidepressants to lengthening of the QT interval, an aspect of the heart's electrical activity that -- when prolonged -- may increase the risk of dangerous arrhythmias.

A 2011 warning from the U.S. Food and Drug Administration about the popular antidepressant citalopram (Celexa) left many patients and physicians with more questions than answers. Now an analysis of the medical records of more than 38,000 patients by Massachusetts General Hospital (MGH) investigators clarifies the contribution of citalopram and other antidepressants to lengthening of the QT interval, an aspect of the heart's electrical activity that -- when prolonged -- may increase the risk of dangerous arrhythmias. The study supported the FDA's warning that higher doses of citalopram were associated with a prolonged QT interval but also found that the effects of some other antidepressants were quite different.

"It was important to confirm the effects of citalopram -- one of the most widely prescribed antidepressants in the U.S. -- because the FDA warning really gave us minimal clinical guidance," says Roy Perlis, MD, of the MGH Department of Psychiatry, corresponding author of the report that will appear in the journal BMJ and is being released online. "The impetus for this study came directly from the phone calls we received from colleagues and from patients taking citalopram asking what they should do. We realized that to get a satisfying answer, we needed to get more data."

Many medications -- including some older antidepressants -- are known to increase the QT interval, which is the time from the beginning of electrical activation of the heart to the end of electrical relaxation. While the vast majority of individuals with QT prolongation have no heart rhythm abnormalities, it is a recognized risk factor for a rare but dangerous arrhythmia called torsades de pointes. To get a better idea of the real-world prevalence of QT prolongation associated with citalopram and other antidepressants, the MGH team embarked on an analysis of the medical records of thousands of patients treated at the MGH and other Partners HealthCare facilities.

"We are fortunate that our colleagues at MGH and Partners have developed incredibly useful tools to answer specific questions by rapidly and simultaneously looking across electronic health record data from tens of thousands of patients while protecting patient confidentiality," Perlis explains. "Working with them we developed a way to look at each EKG report and pull out QT interval information and other relevant results. Doing this by hand -- flipping through individual patient charts -- would have taken a year or more. Doing it with electronic health records took about an hour."

The study examined the health records of 38,397 patients who had an EKG reading taken at a Partners facility between 14 and 90 days after receiving a prescription for one of 11 different antidepressant drugs or for methadone, which is known to prolong QT interval. Their analysis confirmed the association of a slight but significant QT prolongation with higher doses of citalopram, along with the known associations with methadone and with the older antidepressant amitriptyline. The results also associated QT prolongation with the newer antidepressant escitalopram (Lexapro); but many other drugs -- including fluoxetine (Prozac), paroxetine (Paxil) and sertraline (Zoloft) -- had no effect on QT interval. The antidepressant bupropion (Wellbutrin/Zyban) was actually associated with shortening the QT interval.

Perlis cautions that the results of this study should not cause patients taking citalopram or escitalopram to stop taking their medication. "I worry more about people stopping their antidepressants unnecessarily than about the QT prolongation risks," he explains. "For patients starting a new antidepressant who have other risk factors for arrhythmias, a drug other than citalopram would probably be a wise choice. But for those already taking lower doses of either of these drugs, the QT prolongation effects seem to be modest. The real message to patients taking these drugs is to have a conversation with their doctors."

The speed with which the investigators were able to complete their study reflects the power of electronic health record analysis to answer important research questions, he adds. "Finding the QT-shortening effects of bupropion shows how this approach can help us find drugs with unexpected benefits and not just unexpected problems. As long as we're willing to accept the limitations -- particularly the fact that people aren't randomly assigned to different treatments -- this strategy allows us to study many more patients and get answers much faster. In terms of patient privacy, this is actually much safer than the older methods, which required a person to look through a pile of medical records one by one. This way we only extract the data we need and never see anything that would allow us to identify an individual patient." Perlis is an associate professor of Psychiatry at Harvard Medical School.


Story Source:

The above story is based on materials provided by Massachusetts General Hospital. Note: Materials may be edited for content and length.


Cite This Page:

Massachusetts General Hospital. "Antidepressant contribution to arrhythmia risk clarified." ScienceDaily. ScienceDaily, 29 January 2013. <www.sciencedaily.com/releases/2013/01/130129190237.htm>.
Massachusetts General Hospital. (2013, January 29). Antidepressant contribution to arrhythmia risk clarified. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2013/01/130129190237.htm
Massachusetts General Hospital. "Antidepressant contribution to arrhythmia risk clarified." ScienceDaily. www.sciencedaily.com/releases/2013/01/130129190237.htm (accessed September 1, 2014).

Share This




More Health & Medicine News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

Reuters - US Online Video (Aug. 30, 2014) California lawmakers pass a bill requiring universities to adopt "affirmative consent" language in their definitions of consensual sex, part of a nationwide drive to curb sexual assault on campuses. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
New Drug Could Reduce Cardiovascular Deaths

New Drug Could Reduce Cardiovascular Deaths

Newsy (Aug. 30, 2014) The new drug from Novartis could reduce cardiovascular deaths by 20 percent compared to other similar drugs. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins