Histamine2 receptor antagonists (H2A) are one class of drugs that blocks stomach acid.

H2As, including including ranitidine and famotidine, are among the most popular medications prescribed in the United States and sold under the following brand names:Axid®, Pepcid®, Tagamet® and Zantac® - used to treat ulcers, acid reflux and other gastrointestinal disorders.

Now, the long term use of these drugs in older African-American adults may be associated to cognitive impairment - according to an Indiana University School of Medicine and Regenstrief Institute study published in the August issue of the Journal of the American Geriatrics Society.

According to Malaz Boustani, M.D., MPH, assistant professor of medicine at the IU School of Medicine and a Regenstrief research scientist. Dr. Boustani is lead author of the study:

"Taking these medications continuously appears to put older African-Americans at greater risk for the development of cognitive impairment.

We need to study this further to determine how acid blockers might be causing or creating this effect and if it occurs only in African-Americans."

According to the five-year observational study that included 1,558 cognitively normal African-Americans aged 65 and older, the risk for showing signs of cognitive impairment is 2.5 times greater for patients using these medications long-term.

Source: Indiana University School of Medicine