The findings of new research suggests that a broad range of commonly used drugs, including Paxil, Benadryl, Enablex and others, may increase the risk of dementia.
In a study published in the medical journal JAMA Internal Medicine, researchers from England indicate that side effects of anticholinergic drugs, which includes some widely used antidepressants, antipsychotics, Parkinson’s disease treatments and antiseizure medications, may significantly increase the risk of dementia.
“This broad group of drugs acts by blocking the neurotransmitter acetylcholine in the central and peripheral nervous system and includes some antihistamines, antidepressants, and medications for gastrointestinal and bladder disorders,” the researchers noted. “These medicines can have short-term adverse effects, including confusion and memory loss in older people, but it is less certain whether long-term use increases the risk of dementia.”
The findings come from a nested case-control study of 58,769 patients who had been diagnosed with dementia, who were compared to 225,574 matched controls. All of the patients were 55 years old or older. The researchers looked at the use of 56 prescription drugs with anticholinergic properties. They looked at who was prescribed those drugs from one to 11 years prior to a dementia diagnosis.
According to the findings, patients in the highest overall exposure category for anticholinergic drugs were nearly 50% more likely to develop dementia than those who did not take the drugs or those who were in the lowest exposure category.
The findings varied according to the type of anticholinergic drugs. Antidepressants increased the risk of dementia nearly 30%; antiparkinson drugs increased the risk 52%; antipsychotics increase the risk by 70% and increased the risk by the highest amount; while drugs for incontinence increased the risk 65%; and antiepileptic drugs increased the risk nearly 40%.
The researchers also found that associations were stronger in cases where the person was diagnosed with dementia before they turned 80 years old.
“Exposure to several types of strong anticholinergic drugs is associated with an increased risk of dementia,” the researchers concluded. “These findings highlight the importance of reducing exposure to anticholinergic drugs in middle-aged and older people.”