There was a recent article stating that H2 Blockers May Pose Cognitive Function Risk. Should patients worry if they are taking these acid reflux medications?
The above article in the August 2007 issue of Journal of the American Geriatrics Society was written by Malaz Boustani, M.D. of Indiana University. 
More than 1,000 patients -- 1,558 to be exact -- over the age of 65 were observed over time, and after accounting for age, education level and medical history, it was concluded that those treated with H2 receptor antagonists such as Pepcid (left) and Tagamet (right) were 2 1/2 times more likely to develop cognitive impairment. Possible mechanisms include 
H2 blocker induced vitamin B12 deficiency or possible central anticholinergic effects of certain H2 blockers. The study involved only African Americans, and therefore the results might not apply to other ethnic groups. More importantly, this was an observational study, and is in conflict with others.
Additionally, only 17 percent of the patients in the study were on H2 blockers, and determining that was done with only three interviews over a five-year period. Further randomized, clinical trials need to be performed to see if the observations hold up. Such studies should measure cognitive impairment at least once or twice a year, and also insure that the patients have continuous treatment to H2 blockers instead of self-reporting at rare instances.
In conclusion, at this time, there is insufficient evidence to warrant patients worry about cognitive dysfunction due to H2 blockers.
