Proton pump inhibitors and histamine2 receptor antagonists – types of acid suppressive medications commonly taken to treat the overproduction of gastric acid, such as acid reflux (GERD/GORD), dyspepsia, and peptic ulcer disease may raise the risk of pneumonia, researchers from Seoul National University Hospital, South Korea, report in CMAJ (Canadian Medical Association Journal).

Acid suppressive medications are the second highest selling drugs in the world, reaching over $26 billion in 2005. The authors explained that medical literature has been looking more carefully at the impact popular drugs might have on public health.

Dr. Chun-Sick Eom, Dr. Sang Min Park and team carried out a systematic review of all studies related to acid suppressive drugs and pneumonia since August 2009 – they used three sources, MEDLIN E (PubMed), Embase and the Cochrane Library. They found that 1 in every 200 individuals taking an acid suppressive medication developed pneumonia.

The researchers revealed that:

  • Proton pump inhibitor use raised pneumonia risk overall by 27% compared with non-use
  • Histamine2 receptor blocker use raised pneumonia risk overall by 22% compared with non-use

The authors wrote:

    “Several previous studies have shown that treatment with acid-suppressive drugs might be associated with an increased risk of respiratory tract infections and community-acquired pneumonia in adults and children. However, the association between use of acid-suppressive drugs and risk of pneumonia has been inconsistent. Given the widespread use of proton pump inhibitors and histamine2-receptor antagonists, clarifying the potential impact of acid-suppressive therapy on the risk of pneumonia is of great importance to public health.”

A considerable number of hospitalized patients, estimated to be between 40% and 70%, are given acid-suppressive drugs. The researchers suggest that they could contribute significantly towards the hospital-acquired pneumonia totals. Their impact on community-acquired pneumonia rates might be even larger.

Doctors should be cautious about prescribing acid suppressive drugs, the authors wrote, especially if the patient has an elevated risk of developing pneumonia.

Acid suppressive drugs might be prescribed for the following diseases and conditions:

  • Dyspepsia
  • Gastroesophageal reflux disease (GORD/GERD)
  • Laryngopharyngeal reflux
  • Peptic ulcer disease (PUD)
  • Barrett’s esophagus
  • To prevent stress gastritis
  • Gastrinomas and other conditions that cause hypersecretion of acid
  • Zollinger-Ellison syndrome.

“Use of acid-suppressive drugs and risk of pneumonia: systematic review and meta-analysis”
Chun-Sick Eom, Christie Y. Jeon, Ju-Won Lim, Eun-Geol Cho, Sang Min Park and Kang-Sook Lee
CMAJ 10.1503/cmaj.092129

Written by Christian Nordqvist