(dailyRx News) Pre-operative appointments are a good time for patients to discuss with their doctors the risk factors for upcoming surgery. Often, the medications a person is taking can influence that risk.
A recent study found that individuals taking a type of antidepressant were at a slightly higher risk for poor outcomes during surgery.
However, it's not clear if it's the medication or other underlying conditions in those patients that is linked to the poorer outcomes.
It is possible that individuals taking antidepressants have other conditions that increase the risk of a poor outcome from surgery.
The study, led by Andrew D. Auerbach, MD, MPH, of the Department of Medicine at the University of California at San Francisco, looked for any links between surgery outcomes among those who were taking selective serotonin reuptake inhibitors (SSRIs) at the time of surgery.
The researchers looked at the records of all patients aged 18 and older who had major surgery between January 1, 2006 and December 31, 2008 at 375 hospitals in the US. Overall, the study involved 530,416 patients.
The researchers looked at how long the patients remained in the hospital, how many were readmitted within one month, how many died in the hospital, how many had bleeding events or required transfusions and how many had irregular heart beats (arrhythmias) in their lower heart chambers (ventricles).
Patients who were taking SSRIs were, unsurprisingly, more likely to have depression than those who were not taking SSRIs.
While 41 percent of the patients taking SSRIs had been diagnosed with depression, only 6.2 percent of the patients not taking SSRIs had depression.
Those taking SSRIs were also more likely to be obese, to have chronic pulmonary disease (a lung disease) or hypothyroidism, a condition where the thyroid gland does not make enough of the thyroid hormone.
Because of these differences among those who were and were not taking SSRIs while undergoing surgery, the researchers had to make adjustments to their calculations to try to account for these differences.
After making those adjustments, the researchers determined that those taking SSRIs were at about 20 percent higher risk for dying in the hospital and 22 percent higher risk for being readmitted to the hospital within 30 days, compared to those not taking SSRIs.
Those taking SSRIs were also very slightly at higher risk (9 percent more) for bleeding than those not taking SSRIs.
"Receiving SSRIs in the perioperative period [taking them while undergoing surgery] is associated with a higher risk for adverse events," the researchers wrote.
However, the researchers noted that it's difficult to know whether it is the SSRI medications themselves that are related to the poor outcomes, or if those outcomes are more related to the other conditions that people taking SSRIs have.
In other words, even though the researchers tried to adjust for differences in the patients taking and not taking SSRIs, it may not have been possible to completely erase the effects of other issues in those taking SSRIs, such as the lung disease, depression or obesity.
"Rather than being a risk factor itself, use of SSRIs in patients with depression may simply be a marker for other factors, such as more severe mood disorders, poorer functional status, neuropathy, or chronic pain, many of which are associated with a higher risk for readmission or mortality," the researchers wrote.
"As the study says, many patients on SSRIs have other underlying disease states that can severely affect outcomes after a surgery of any kind," said pharmacist Mark Newberry, PharmD, a dailyRx expert and owner of Tarrytown Pharmacy in Austin, Texas.
"A patient on an SSRI has to weight the benefit versus the risk of taking the drug, as our patients must do with any medications prescribed," Dr. Newberry said. But that does not mean that a patient should discontinue taking SSRIs without consulting a medical professional.
"SSRIs have been proven safe and more importantly very effective for the treatment of many neurological disorders," Dr. Newberry said. "Discontinuing an SSRI, even for a very short period, is a serious undertaking which would mandate a conversation with their physician before doing so."
The study was published April 29 in the journal JAMA Internal Medicine. The research was funded by the National Heart, Lung and Blood Institute. The authors declared no conflicts of interest.