For older adults taking antidepressants, newer drugs may bring more health risks than older drugs, a new study from British researchers suggests.
In the study, adults over 65 who took newer generation antidepressants — selective serotonin reuptake inhibitors , or SSRIs — had a greater risk having a stroke or seizures than those who took older generation antidepressants, or tricyclic antidepressants, TCAs.
The findings are contrary to the prevailing view that SSRIs are safer than TCAs.
The results were unexpected, and more work is needed to confirm them, said study researcher Carol Coupland, an associate professor in medical statistics at the University of Nottingham in the United Kingdom. For now, it is important that doctors carefully consider the risks and benefits of each type of antidepressants before prescribing them to older adults, Coupland said.
The new study was published online today (Aug. 2) in the journal BMJ.
New vs. old antidepressants
Few studies have looked at the benefits and harms of antidepressants in older adults , a population that is at particular risk for suffering side effects of drugs, the researchers said.
Using a database of patients in primary care in the United Kingdom, Coupland and colleagues identified more than 60,700 people ages 65 and over who were diagnosed with depression between 1996 and 2007, and followed these patients until 2008.
The average age of participants was 75. Many suffered from other illness, including heart disease and diabetes, and were taking multiple medications.
Nearly 90 percent of patients were prescribed an antidepressant during the study period. Of those, 55 percent received SSRIs, 32 percent received TCAs, and 13.5 percent received other antidepressants.
Those taking SSRIs had an increased risk of stroke, falls, fracture, epilepsy or seizures , high levels of salt in the blood and dying of any cause, compared with those taking TCAs.
The findings held even after the researchers took into account factors including the participant's age, sex, severity of depression, other illnesses and use of other medications, that could have affected the results.
Depressed patients not taking any antidepressant had a 7 percent risk of dying over one year. The risk for those on TCAs was 8.1 percent and the risk for those on SSRIs was 10.6 percent, the study showed.
Older adults taking TCAs were generally given lower doses of the drugs than those taking SSRIs, the researchers say, which might partly explain their results.
However, it's possible that those taking SSRIs are more prone, in general, to health risks.
Sicker patients may be more likely to be prescribed SSRIs because these drugs are thought to have fewer side effects, said Dr. Michael Katsnelson, assistant professor of neurology at the University of Miami Miller School of Medicine.
"If you have a patient [taking] 10 drugs and you know tricyclics have a lot of side effects, you could be more hesitant to prescribe these drugs," Katsnelson said.
There is still a lot of evidence that SSRIs are safe, Katsnelson told MyHealthNewsDaily. Ultimately, researchers won't know whether SSRIs or TCAs are safer for older adults until they conduct a clinical trial in which patients are randomly assigned to receive one drug or the other, he said.
Treatment of depression is particularly important in older adults because studies have linked depression to memory loss in this population, Katsnelson said. In addition, if older adults are depressed, they might not have the motivation to take care of their other medical problems, he said.
Pass it on: Clinical trials of antidepressants in older adults need to be conducted to determine whether one class of drugs is safer than the other.
Follow MyHealthNewsDaily staff writer Rachael Rettner on Twitter @RachaelRettner.