This common practice when taking pills could risk a seizure in older adults, study warns

Researchers urge older adults taking antidepressants like fluoxetine or paroxetine to be cautious while taking opioid painkillers

Taking the pain medication tramadol along with some common antidepressants could raise seizure risk in older adults, a new study has warned.

The research, published in the journal Neurology, found that older adults living in nursing homes, who were prescribed the opioid pain medicine tramadol alongside some antidepressants, faced a higher risk of seizures.

Researchers from the American Academy of Neurology warn that antidepressants inhibiting the enzyme CYP2D6 – called CYP2D6 inhibitors – can interfere with how the body metabolises tramadol.

These antidepressants include the commonly prescribed fluoxetine, paroxetine and bupropion.

Tramadol has also come under the scanner recently as the painkiller was found to offer only a slight alleviation for chronic pain, with its potential side effects possibly outweighing any perceived benefits, according to a recent study.

When the CYP2D6 enzyme is blocked, tramadol is not metabolised properly and may build up in the body, potentially increasing the risk of side effects like seizures, scientists warned.

“We found a modest but measurable increase in the risk of seizures when tramadol was taken with antidepressants that inhibit the CYP2D6 enzyme,” said Yu-Jung Jenny Wei, an author of the study from The Ohio State University in Columbus.

“This risk was consistent whether the antidepressant or tramadol was started first,” Dr Wei said.

This photo illustration shows different tablets of medicines kept together, in Kolkata (AFP via Getty Images)

In the study, researchers analysed 10 years of Medicare data to identify 70,156 nursing home residents age 65 and older who had been prescribed both tramadol and an antidepressant.

The participants were divided into two groups based on which drugs they took first.

Over 11,100 people took tramadol first and then an antidepressant with it, while nearly 59,000 people took an antidepressant first and then added tramadol.

Researchers found that for every 100 people who used both tramadol and an antidepressant, who were followed for one year, about 16 or 20 received a seizure diagnosis.

Scientists then compared seizure rates between those who took tramadol along with CYP2D6-inhibiting antidepressants, and those who took tramadol with antidepressants that do not inhibit the enzyme.

They found that for people who took tramadol first, seizure risk was 9 per cent higher when taking it with a CYP2D6-inhibiting antidepressant, compared to those who took an antidepressant that did not inhibit this enzyme.

When researchers repeated the analysis using another opioid pain reliever, hydrocodone, they found it is unlikely to cause seizure risk when used with antidepressants.

“These findings underscore the need for careful prescribing practices, especially for older adults with complex health conditions,” Dr Wei said.

“Doctors should be aware of potential seizure risks when prescribing tramadol with antidepressants, particularly CYP2D6 inhibitors. Given how commonly both are prescribed to older adults, these interactions may be more important than previously thought,” she said.

Citing one limitation of the study, researchers said the results were derived based on patient prescription records, meaning it does not confirm whether the participants took the drugs as directed.

However, scientists urge clinicians to be mindful of seizure risk in older patients who use “tramadol concomitantly with antidepressants, particularly CYP2D6-inhibiting antidepressants”.