The Beers Criteria is a list of medications that "older Americans" should "avoid or use with caution".
"Older" is over 65 years old.
"American" means United States.
"Avoid or use with caution" means that the American Geriatric Society has a list of medications that could cause harm in "older" "Americans".
Many people of all ages in the United States are on way too many medicines plus supplements plus vitamins plus herbs.... too many pills. Anything concentrated in a lab may be concentrated enough to be a challenge for the body to metabolize once it's absorbed. The calculation of kidney function includes age which means that 9 out of 10 of my patients over 90 are in "stage III chronic renal failure". This means that you have to lower antibiotic and other drug doses because the kidneys don't clear them. Kidney failure can kill. Most of my over 80 year old patients are stage III as well and some 70 year olds. The liver seems to do well unless the person has trashed it with alcohol, hepatitis B or C, methamphetamines or some horrid overdose.
How many of my patients over age 65 are on a medicine on the Beers Criteria list? Most of them, I suspect. I try to keep medicines to a minimum, but hello, practically every medicine is on that list. I get "Big Brother" letters from the patients' insurance company saying "Mr So-n-so is OVER 65 and ON A BEERS CRITERIA PHARMACEUTICAL!" Rather than throw these out, I kindly offer to the insurance company to have a visit with the patient where I will tell them that they are on it, but they need it and no there isn't anything that is better/or not on the list. Insurance corporations love me.