A couple of years ago, I posted something about a couple of antihistamines that had a tendency to screw up, so to speak, one’s libido. The title — “Friends with Benadryl” — got no reaction whatsoever, perhaps because we have a tendency to venerate drugs that do us a favor. We also have a tendency to forget that every drug has side effects, and sometimes those side effects can be nasty:
A new study, published Monday, offers the most definite proof yet of what scientists have known for at least a decade: that anticholinergic drugs [pdf] are linked with cognitive impairment and an increased risk of dementia.
Though you may have never heard of this class of drug, you’ve certainly heard of the medications themselves, including Benadryl, Demerol, Dimetapp, Dramamine, Paxil, Unisom and VESIcare. They are sold over the counter and by prescription as sleep aids and for chronic diseases including hypertension, cardiovascular disease and chronic obstructive pulmonary disease (COPD).
At the link, there’s a scale for various drugs, each of which is assigned an anticholinergic “burden score” of 1 to 3 points, 3 being the worst: “Evidence from literature, expert opinion, or prescribers information that medication may cause delirium.” The brand names mentioned in the article generally score 3.
The new study [pdf] seems to reinforce this judgment:
The study looked at 451 people, with an average age of 73. Sixty of them were taking at least one medication with medium or high anticholinergic activity. To identify physical and physiological changes that could be associated with the reported effects, researchers assessed the results of memory and cognitive tests; PET scans, to measure brain metabolism; and MRI scans, to assess brain structure.
The cognitive tests revealed that people taking anticholinergic drugs performed worse on short-term memory tests, as well as on some tests of executive function, including verbal reasoning, planning and problem-solving.
Anticholinergic drug users also showed lower levels of glucose metabolism — a biomarker for brain activity — both in the brain overall and in the hippocampus, a region of the brain associated with memory and which has been identified as affected early by Alzheimer’s disease. The participants using anticholinergic drugs were also found to have reduced brain volume and larger ventricles, the cavities inside the brain.
The catch here is that those 60 individuals were taking those meds on a regular basis, presumably allowing the deleterious effects to accumulate. The conclusion is actually rather modest: for older patients, at least, it might be wise to seek alternative treatments. Of course, since this came out on CNN, there are going to be shrieks of “We’re All Gonna Die,” exactly as there are for any such health stories that get into the popular press. That said, I have about 500 tabs of Sominex (AC burden score: 3) that I may just chuck into the landfill.