The antidepressants mirtazapine—sold under the brands Remeron, Avanza, and Zispin—and fluoxetine (known as Prozac, Sarafem, or Fontex) have been associated with an increased risk Clostridium difficile infection (CDI), according to new research.
Investigators at the University of Michigan in Ann Arbor discovered that the antidepressants were associated with a two-fold increased risk for CDI, especially in older people who live alone, said Medscape. “Clinicians prescribing antimicrobials to patients with depression should be aware of the possible increased risk of CDI in this patient population,” lead author Mary A. M. Rogers, PhD, told Medscape Medical News. The study appears in BMC Medicine.
The researchers discovered the ancillary finding from prior research that suggested that antidepressant medications increase risks for developing Clostridium difficile infection, according to BMC Medicine. The researchers noted that their objective was to evaluate if depression or antidepressant use changed risks for developing the infection, BMC Medicine explained.
It seemed the team discovered an article on an outbreak investigation published by epidemiologists from the Centers for Disease Control and Prevention (CDC) that found that CDI patients were three times likelier to suffer from psychoses and depression than those in the control individuals, said Medscape. The team then found that some Canadian pharmacists published a study on medications associated with CDI in two hospitals and that, of the drugs reviewed, antidepressants were most strongly associated with CDI.
“Both of these observations were essentially buried as minor findings in the medical literature, but as we reviewed these studies and looked at our own data, we began to see a pattern, and so decided to follow this trail,” the researchers said.
The researchers concluded that adults with depression and who take these specific antidepressants are likelier to develop CDI, said BMC Medicine. Specifically, people diagnosed with major depression were 36 percent likelier and people with depressive disorders were 35 percent likelier to develop CDI. Older adults who are widowed and/or live alone were at a 54 percent increased risk for the serious infection.
C. difficile-associated diarrhea is a severe form of diarrhea caused by C. difficile bacteria. Illness from C. difficile most commonly affects older adults in hospitals or in long-term care facilities and was long believed to occur after use of antibiotic medications.
Commenting on this study for Medscape Medical News, Alan J. Gelenberg, MD, Shively/Tan Professor and chair of psychiatry at the Pennsylvania State University, said he found the study “very interesting” and that the research “looks sound, noting that, “It’s not as obvious as to why fluoxetine rather than other members of the SSRI [selective serotonin reuptake inhibitor] class of antidepressants should be associated, but the association is strengthened by the dose-response relationship with the 2 antidepressants they cited.” he said. “When patients are in the hospital and going to be placed on antibiotics, and they’re also on one of these antidepressants, their doctors should be particularly watchful and cautious.”