Have you ever noticed that an older family member seems more forgetful, confused, or unusually sleepy after starting a new medication? While many factors can affect memory and thinking, certain medicines can contribute to these symptoms, particularly in older adults.
Some medications affect chemical messengers in the brain, while others cause drowsiness, dizziness, or confusion. In some cases, taking several medications together can increase these effects.
Research has also identified associations between long-term use of certain medications and an increased risk of dementia. However, an association does not prove that a medicine directly causes dementia, and not everyone who takes these medications experiences cognitive problems.
Understanding which medicines deserve attention can help you have a more informed conversation with your doctor or pharmacist.
1. Certain Antihistamines for Allergies and Sleep
Some older antihistamines have anticholinergic effects, meaning they block the action of acetylcholine, a chemical messenger involved in memory, attention, and other brain functions.
Examples include diphenhydramine and chlorpheniramine. These ingredients can be found in some allergy medicines and over-the-counter nighttime products.
Possible side effects include:
- Drowsiness.
- Difficulty concentrating.
- Confusion, particularly in older adults.
- Problems with memory and attention.
Frequent use of medications with strong anticholinergic effects has been associated with a higher risk of dementia in observational studies. However, these studies do not establish that the medicines directly cause dementia.
What to do: Check the active ingredients in allergy and sleep products, and ask a healthcare professional whether a less sedating alternative would be appropriate. Do not assume that an over-the-counter product is risk-free.
2. Benzodiazepines Used for Anxiety or Sleep
Benzodiazepines are prescribed for conditions such as anxiety, certain seizure disorders, and some sleep-related problems.
Examples include diazepam, lorazepam, and clonazepam.
These medicines slow activity in the central nervous system. Depending on the dose and individual response, they may cause:
- Sleepiness and reduced alertness.
- Short-term memory difficulties.
- Confusion.
- Slower reaction times and an increased risk of falls.
