Patients with chronic obstructive pulmonary disease (COPD) on antidepressants are at increased risk for pneumonia and exacerbations, according to study findings published in Thorax.
Investigators sought to evaluate possible associations between antidepressant use and increased risk of pneumonia or exacerbations in patients with COPD.
The investigators conducted a self-controlled case series comparing patients with and without antidepressant exposure for rates of pneumonia and exacerbation. Patients were at least 40 years of age with a mean age of 65 years.
The investigators used the Health Improvement Network database (of more than 12 million anonymized electronic health records from more than 550 general practices in the United Kingdom) from January 2004 through December 2015 to identify patients with COPD and at least 1 antidepressant prescription who had pneumonia or COPD exacerbations.
Researchers defined days 1 to 90 as the risk period; they defined day 91 until the end of the course as the remainder period; they defined the immediate 90 days after the end of the course as the wash-out period.
This study shows that antidepressant prescription increased the risk of pneumonia and COPD exacerbation in patients with COPD. These risks diminished once the treatment has stopped.
Among more than 31,000 patients with COPD and at least 1 antidepressant prescription, 613 patients had pneumonia and exacerbations. Investigators included these 613 patients as part of the 1969 total patients in the analysis who had pneumonia and also as part of the 18,483 total patients in analysis who had COPD exacerbation.
The 90-day risk period after antidepressant prescription was associated with a 79% increased risk for pneumonia (age-adjusted incidence rate ratio [IRR], 1.79; 95% CI, 1.54-2.07) and a 16% increased risk for COPD exacerbation (age-adjusted IRR, 1.16; 95% CI, 1.13-1.20). Pneumonia risk continued throughout the remainder period (age-adjusted IRR, 1.88, 95% CI, 1.68-2.11). COPD exacerbation risk continued and increased slightly in the remainder period (age-adjusted IRR, 1.38; 95% CI, 1.34-1.41).
After antidepressants were discontinued in the wash-out period, risk of pneumonia and exacerbation decreased. Investigators found no obvious confounding due to seasonal effects.
Study limitations include using prescription data as a proxy for adherence, as well as failure to comprehensively capture pneumonia or COPD exacerbation events diagnosed at hospital admission.
Investigators concluded, “These findings support the monitoring of side effects associated with antidepressants and that non-pharmacological therapies should be considered.” They stated, “This study shows that antidepressant prescription increased the risk of pneumonia and COPD exacerbation in patients with COPD. These risks diminished once the treatment has stopped.”
Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.