Nearly 100 common drugs linked to increased risk of thinking and memory problems

MINNEAPOLIS — A new study is sounding the alarm for patients taking dozens of common prescription and over-the-counter drugs. Researchers find that taking a particular class of drug, anticholinergics, increases the risk of developing mild thinking and memory problems.

The study shows there are about 100 of these types of drugs in widespread use. These medications treat everything from colds to high blood pressure to depression.

The research, published in the journal Neurology, finds that people with genetic risk factors for Alzheimer’s disease are particularly susceptible to these issues. Overall, scientists reveal patients with no cognitive issues are 47 percent more likely to develop a mental impairment if they’re taking at least one anticholinergic drug.

“Our findings suggest that reducing the use of anticholinergic drugs before people develop any cognitive problems may be an important way to prevent the negative consequences of these drugs on thinking skills, especially for people who have an elevated risk of developing Alzheimer’s disease,” study author Lisa Delano-Wood from the University of California, San Diego says in a press release.

How common are anticholinergics?

Researchers say these drugs have a wide range of uses, treating both common health issues and serious diseases. Patients take them for conditions like motion sickness, urinary incontinence, and overactive bladders. Anticholinergics are also prescribed to manage Parkinson’s disease and high blood pressure.

Metoprolol, atenolol, loratadine, and bupropion are among the most common medications in the anticholinergic drug class.

The study examined 688 people with an average age of 74. Researchers report none of the participants had any trouble with thinking or memory at the start of the decade-long review.

Study authors also find that people on anticholinergics are usually taking several of these drugs at once. Overall, one-third of the participants were found to be taking some sort of anticholinergic medication and the average patient was using four to five anticholinergic drugs.

Concerning links to Alzheimer’s disease

The report looks at cognitive tests taken by the group once a year throughout the 10 years. Out of the 230 taking anticholinergic drugs, 117 (51 percent) went on to develop mild cognitive impairments. Among those participants not taking these drugs, only 42 percent would eventually have these problems.

After adjusting for depression, the number of medications taken, and each patient’s history of cardiac problems, study authors arrived at their 47-percent risk determination. They add that higher exposure to anticholinergics increase this risk factor.

When studying human biomarkers for Alzheimer’s disease, an even greater chance of having cognitive problems emerges. Researchers say people with risk factors for Alzheimer’s in their cerebrospinal fluid are four times more likely to be affected by anticholinergic drugs.

Those with other genetic risk factors for Alzheimer’s are 2.5 times more likely to develop mild cognitive impairments.

Dosing may be tied to memory problems

Delano-Wood and her team also say the majority of patients are likely taking much higher doses than may be needed for older adults. In fact, the report shows 57 percent take twice the minimum recommended dosage and 18 percent take four times that amount.

“This is of course concerning and is a potential area for improvement that could possibly lead to a reduction in cases of mild cognitive impairment,” says Delano-Wood.

The study notes that the results are limited by the patient sample size and the fact that only a third are taking anticholinergic drugs. Researchers say other studies find the number of older adults taking anticholinergics is actually near 70 percent.

While the results point to possible issues with these medications, study authors recommend patients speak with their doctor or pharmacist before suddenly stopping use of their prescriptions.