A new UK study finds that among individuals 65 or older, taking new generation antidepressants (SSRIs) is riskier than older tricyclic antidepressants (TCAs), increasing the likelihood of stroke, falls, even death.

Increased risk associated with SSRIs include dying or suffering from a range of serious health conditions including stroke, falls, fractures and epilepsy, say researchers at The University of Nottingham.

The research is published by the British Medical Journal website bmj.com.

The authors said the risks and benefits of different antidepressants should be carefully considered when prescribing these drugs to elderly patients. Additional research has been called for to further investigate the findings.

Researcher Carol Coupland, Ph.D., said: “We’ve found some evidence from our study that the older tricyclic antidepressants may be associated with lower risks of several adverse outcomes compared with newer antidepressants in older people diagnosed as having depression.

“This was an unexpected finding, and so further research using other data sources is needed to confirm these findings as well as provide more evidence on the benefits of different antidepressants in this group of people.”

Despite the widespread use of these drugs, researchers say very little is known about their safety for older people.

In the study, researchers from the Universities of Nottingham and East Anglia set out to investigate the potential link between antidepressant treatment and the risk of a number of potentially life-threatening outcomes in older people.

They identified 60,746 UK patients aged 65 and over with a newly diagnosed episode of depression between 1996 and 2007.

Patients were then tracked until the end of 2008. During this time, 89 percent (54,038) received at least one prescription for an antidepressant, and a total of 1,398,359 prescriptions for antidepressants were received.

Of these 57 percent were for SSRIs, 31 percent for TCAs, 0.2 percent for monoamine oxidase inhibitors (MAOIs) and 13.5 percent for other antidepressants.

After adjusting for factors that could affect the results, including age, sex, severity of depression, other illnesses and use of other medications, the team found that SSRIs and drugs in the group of other antidepressants were associated with an increased risk of several adverse outcomes compared with TCAs.

Those taking SSRIs were more likely to die, suffer a stroke, fall or fracture, have epilepsy or a seizure and have low blood sodium compared with TCAs. The group of other antidepressants were associated with an increased risk of mortality, attempted suicide or self-harm, stroke, fracture and epilepsy or seizures.

Among individual drugs, trazodone (brand name Desyrel), mirtazapine (Remeron) and venlafaxine (Effexor) carried the highest risk for some adverse outcomes.

Most adverse outcomes occur in the 28 days after starting the antidepressant and also in the 28 days after stopping.

The authors also point out that TCAs were prescribed at lower doses than SSRIs and other antidepressant drugs, which they say “could in part explain our findings.”

They also caution that differences between patients prescribed different antidepressant drugs may account for some of the associations seen in the study, underlining the need for further research to confirm the findings.

Source: University of Nottingham