Brain; Mental Health
Anticholinergic drugs: A potential link to dementia
March 28, 2019
Depression rates are at an all-time high in the U.S. and so is the use of medication to combat it. According to the National Institutes of Health, antidepressant use in the U.S. increased nearly 65 percent from 1999 to 2014.
This rise in the use of antidepressants has some researchers once again speculating about the long-term effects the drugs could have on patients. While the potential for memory-related risks with the use of certain antidepressant medications is not necessarily new news, interest in the topic has been rekindled in recent months.
As such, a first-of-its-kind study published in April 2018 in the journal BMJ suggests that patients with a history of taking certain medications from a class of drugs known as anticholinergics – which include some drugs that have been commonly prescribed for depression, among other conditions – might be at increased risk of dementia over time.
Anticholinergic drugs block the effects of acetylcholine (Ach), a neurotransmitter in the brain that stimulates muscle contractions and plays a role in learning, memory, and attention. Aside from depression, these drugs historically have been prescribed for a variety of conditions, such as:
Because it can be confusing for patients to keep up with this topic, we’ve put together the most current information about these drugs and what patients need to know about their risk.
Which drugs increase the risk for dementia?
The study looked back in time at drugs that were commonly prescribed several years ago that might have played a role in the development of dementia in patients 65 to 99. Researchers found that the following types of anticholinergic medications carried the highest risk:
• Antidepressants, such as amitriptyline and paroxetine
• Bladder disorder medications, such as oxybutynin and tolterodine
• Antiparkinson medications, such as benztropine and procyclidine
Many of the medications covered in the study, including some older antidepressants, are no longer frequently prescribed today because more advanced drugs with fewer side effects have been developed. But the BMJ study is an important start in this discussion. To determine more defined risk factors, it will be necessary to conduct a future-looking study of young adults today who take anticholinergic medications and evaluate incidents of dementia decades from now.
What patients need to know
When it comes to individual risk, dosage is an important factor for some medications. If you take just one anticholinergic drug, the effects you might experience likely will be less severe than if you take several drugs with high anticholinergic activity. The length of time that you take the drugs also might affect your risk.
The risks described in this study do not extend to every medication prescribed for depression, urinary symptoms, or Parkinson’s disease. For depression, paroxetine was the only drug in the class of selective serotonin reuptake inhibitors (SSRIs) that carried the higher risk. Other medications with very low anticholinergic effects are also commonly prescribed for depression. These include serotonin and norepinephrine reuptake inhibitors (SNRIs), such as desvenlafaxine (Pristiq), and norepinephrine and dopamine reuptake inhibitors (NDRIs), such as bupropion (Wellbutrin).
If your doctor recommends an antidepressant medication, educate yourself about how the drug works to make an informed decision. Your doctor will help you weigh the benefits and potential risks and help you choose the right medication for your condition.