Drugs that reduce gastric acid secretion can increase a person's risk of pneumonia, according to results of a study involving more than 300,000 people. People taking proton pump inhibitors such as esomeprazole (Nexium), lansoprazole (Prevacid), and omeprazole (Prilosec) had almost twice the risk of developing community-acquired pneumonia as former users of these drugs.
Proton pump inhibitors are commonly prescribed to treat heartburn and other symptoms associated with gastroesophageal reflux disease. Researchers theorize that by reducing germ-killing stomach acid, these drugs allow pathogens from the upper gastrointestinal tract to colonize the respiratory tract.
Researchers reviewed the medical records of 364,683 patients and identified 5,551 cases of pneumonia. They found that 185 of these infections occurred in people taking acid-suppressing drugs. Researchers say their findings translate to about one case of pneumonia for every 226 patients taking proton pump inhibitors. Histamine2-receptor antagonists, such as cimetidine (Tagamet) and famotidine (Pepcid), also raised the risk of pneumonia, but not as much: For patients taking these drugs, the findings translate to about one case of pneumonia for every 508 patients.
Risk of community-acquired pneumonia and use of gastric acid-suppressive drugs, JAMA, RJ Laheij, et al., October 27, 2004.