Researchers say repeated use certain drugs for gastric reflux or peptic ulcers is linked to a higher risk for dementia among patients in Germany.
The class of drugs—proton pump inhibitors (PPIs)—includes Prevacid (lansoprazole), manufactured by Novartis, Nexium (esomeprazole) and Prilosec (omeprazole), both made by AstraZeneca, Reuters Health reports.
Senior author Britta Haenisch of the German Center for Neurodegenerative Diseases, located in Bonn, Germany, says the study can provide only a statistical association between PPI prescriptions and occurrence of dementia in the elderly, but it cannot prove that PPIs actually cause dementia. Haenisch told Reuters Health by email that the researchers “focused on long-term regular PPI prescription for at least 18 months.” They reviewed medical records from 2004 through 2011 from more than 73,000 patients age 75 and older, most of them women. They classified 2,950 patients as regular PPI users, meaning they had at least one prescription for one of the drugs every four or five months over an 18-month period. These drugs are also available in over-the-counter formulas, though the researchers looked at prescription PPIs.
During the study period, 29,510 people developed dementia. Regular PPI users were 44 percent more likely to develop dementia than those who were not taking the drugs, according to Reuters Health. The study was published online on February 15, 2016 in JAMA Neurology. Haenisch said the authors could not know whether some of the study subjects were at increased risk for dementia to start with.
PPI use and dementia may both be influenced by similar risk factors, Dr. Lewis H. Kuller of the University of Pittsburgh wrote in an editorial accompanying the study. Kuller noted that in the Women’s Health Initiative, women who took PPIs were more often obese, had arthritis, and were generally in poorer health than others, which may increase dementia risk. The drugs are known to carry an increased risk of kidney disease, fracture, low magnesium levels, gastrointestinal infections, Clostridium difficile infection and pneumonia, Reuters Health reports.
“PPIs used for the treatment of gastroesophageal reflux disease and peptic ulcers work by reduction of gastric acid production,” Haenisch explains. “The underlying mechanism by which PPIs might influence cognition is yet to be determined.” Some of the drugs may cross the blood-brain barrier and interact with brain enzymes, or they may be associated with vitamin B12 deficiency, which may promote neurological damage, according to Haenisch.
Haenisch advises patients taking PPIs to follow their doctor’s instructions. “To evaluate cause and effect relationships between long-term PPI use and possible effects on cognition in the elderly randomized, prospective clinical trials are needed.”
Doctors should take care not to overprescribe PPIs, which is reported frequently, Haenisch said. One study found that up to 70 percent of the drug prescriptions were inappropriate for the patient, according to Reuters Health.