[EXPLAINER] List of drugs linked to dementia, By Nicole Rowe

Key takeaways: Certain medications are linked to an increased risk of dementia. But that doesn’t mean they necessarily cause dementia.

• Medications that have been associated with increased risk of dementia include overactive bladder medications, pain medications, heartburn medications, and certain anxiety medications.
• The risk of dementia with these medications increases when you take higher doses over longer periods of time.
• Dementia is a growing concern among many aging people in the U.S., especially Alzheimer’s disease. And since treatment options for dementia are limited, prevention is key. 
• Dementia risk is tied to common things like diabetes, high blood pressure, and physical inactivity. But some common medications are associated with dementia risk, too. Here are four common drug classes linked to dementia, and what the research says about your risk.

1. Anticholinergic medications

• Anticholinergic medications block a chemical called acetylcholine in the body. Acetylcholine works like a chemical messenger in the nervous system. It affects learning, memory, movement, and even emotions. And people with Alzheimer’s disease often have low levels of acetylcholine in their bodies. 
• In one large study of almost 300,000 people, the risk of dementia was significantly higher in those who had taken the highest cumulative doses of strong anticholinergic medications.  Another large study in adults over 65 years old confirmed these findings. Other studies have shown that the use of an anticholinergic medication can worsen dementia in people who are already experiencing cognitive decline.  
• But not all studies have such clear-cut findings. For example, even though diphenhydramine (Benadryl) has strong anticholinergic activity, current research is unclear on whether diphenhydramine increases the risk of dementia. 
• Some common anticholinergic medications include antihistamines, tricyclic antidepressants, medications for irritable bowel syndrome (IBS), and overactive bladder medications. You may want to take this risk into account if you’re deciding whether to take these medications.

Antihistamine medications include: 

• Diphenhydramine (Benadryl, Advil PM, Tylenol PM)
• Chlorpheniramine (Chlor-tab, Aller-Chlor, Coricidin HBP)
• Doxylamine (Unisom)

Tricyclic antidepressants include: 

• Doxepin (Silenor) 
• Nortriptyline (Pamelor) 
• Amitriptyline (Elavil)

IBS medications include: 

• Hyoscyamine (Levsin) 
• Dicyclomine (Bentyl)

Overactive bladder medications include:

• Darifenacin ER (Enablex)
• Oxybutynin (Ditropan)
• Tolterodine (Detrol, Detrol LA)
• Trospium (Sanctura)
• Solifenacin (Vesicare)
• Fesoterodine (Toviaz)

2. Proton pump inhibitors

Studies suggest that men and women with dementia are more likely to be taking proton pump inhibitors (PPIs), 1.5 and 1.4 times, respectively. This doesn’t necessarily mean that PPIs directly cause dementia — only that there appears to be an association between the two. There are a couple of theories about how these medications could increase dementia risk:

• PPIs have been shown to cause proteins, called β-amyloid plaques, to build up in the brains of mice. This is similar to the way someone’s brain changes with Alzheimer’s. 
• Long-term use of PPIs could affect the absorption of vitamin B12, which could also increase your risk for dementia.

PPIs include:

• Omeprazole (Prilosec)
• Lansoprazole (Prevacid)
• Esomeprazole (Nexium)
• Pantoprazole (Protonix)

3. Pain medications

Many people are aware that the use of opioid pain medications can lead to dependence, overdose, and even death. But in addition to these concerns, studies show that people with heavy, long-term use of opioid medications have a slightly higher risk of getting dementia. Even people taking nonsteroidal anti-inflammatory drugs (NSAIDs) for pain had a high risk of developing dementia. 

It’s unclear whether the risk of dementia is related to taking pain medication or to the effects of chronic pain on the brain, or both. One newer study showed that older adults with chronic pain had a higher risk of developing dementia. This study didn’t measure how many of these adults were taking pain medications, so additional research is needed. 

Opioid medications include: 

• Morphine
• Hydrocodone (Norco)
• Hydromorphone (Dilaudid)
• Fentanyl (Duragesic)

NSAIDs include:

• Naproxen (Aleve, Naprosyn)
• Ibuprofen (Motrin, Advil)
• Indomethacin (Indocin)

4. Benzodiazepines

Benzodiazepines (benzos) have been linked to dementia — especially in older adults. But not all research supports this link. 

Regardless, older adults should be cautious with these medications. Benzodiazepines can cause many other concerning side effects, including long-term dependence, breathing problems, confusion, drowsiness, problems with cognition, and even death. The risk for impaired brain functioning is increased with higher doses over an extended period of time.

Benzodiazepine medications include:

• Lorazepam (Ativan)
• Clonazepam (Klonopin)
• Diazepam (Valium)
• Alprazolam (Xanax, Niravam)

The bottom line

Many medications have been associated with an increased risk of dementia — especially if you take them for a long time. As with any medication, it’s important to weigh the pros and cons to figure out what’s best for you and your long-term health. 

If you rely on any of these medications to stay healthy, work with a healthcare professional to determine the lowest dose that will still treat your symptoms. This will decrease your risk of any associated side effects, including dementia.  

Dr. Nicole Rowe, MD, is a telehealth family practice physician. She received her medical degree from the University of North Carolina School of Medicine and completed her residency in family medicine atthe University of Colorado’s Swedish Medical Center.