Benzodiazepines may increase the risk of contracting pneumonia by as much as 50% and also increase the risk of dying from it, according to a British study.
Benzodiazepines have a wide range of uses and are commonly prescribed for anxiety, epilepsy, muscle spasm and insomnia. They also are frequently used in palliative care and as sedatives, according to background information for the study, which appeared Dec. 5 on the website of the journal Thorax. Around 2% of the population in the United States and United Kingdom have taken benzodiazepines for 12 months or more, and among the elderly the rate rises to 10%.
The use of these drugs has been linked to a heightened risk of infections and death from sepsis in critically ill patients, and researchers wanted to investigate whether they had a similar impact on the risk of developing fatal pneumonia.
The authors analyzed the health records of patients whose details had been entered into the UKs Health Improvement Network database, which contains the records of more than 9 million patients registered with various primary care organizations.
They focused on almost 5,000 patients with an initial diagnosis of pneumonia between 2001 and 2002 and compared each with six patients, matched for age and sex and drawn from the same practice, for a total of more than 29,500 controls. The use of zopiclone, which is not a benzodiazepine but acts on the same chemical pathways in the body, also was assessed.
The results showed that benzodiazepines as a class of drug were associated with a 54% higher risk of contracting pneumonia after accounting for previous bouts of the infection, smoking status and other serious and underlying illness. An effect of similar magnitude was found for the use of zopiclone.
Individually, prescriptions for diazepam, lorazepam and temazepam, but not chlordiazepoxide, were associated with an increased risk of contracting pneumonia.
A second analysis showed the risk of dying within 30 days of being diagnosed with pneumonia was 22% higher among those taking benzodiazepines. For the period spanning three years after diagnosis, the risk was 32% higher. Diazepam, chlordiazeopoxide, lorezapam and temazapam all were individually associated with the long-term risk of death in these patients.
The authors cautioned that their findings do not definitively prove cause and effect, but indicate there may be grounds for further investigation, especially given that the results echo those of clinical trials of sedative doses of benzodiazepines.
“Benzodiazepines and zopiclone are commonly prescribed medications that have significant immune effects,” the authors wrote. “Given the widespread use of benzodiazepine drugs, further studies are required to evaluate their safety in the context of infection.”
The study abstract is available at http://thorax.bmj.com/content/early/2012/11/12/thoraxjnl-2012-202374.abstract?sid=5baf329f-9b4e-4120-aea3-3f3d686f631f.