Medications That Can Affect Memory: A Reason to Review, Not to Stop
Several widely used drug classes have recognised cognitive effects. Reviewing them with a prescriber is one of the more productive steps in a memory evaluation.
Do not stop or change any prescribed medication based on this article. Some medications are dangerous to stop abruptly. This page exists to help you have a conversation with your doctor or pharmacist, not to replace one.
Medication effects are among the more commonly identified contributors when someone is evaluated for memory complaints, and they are frequently overlooked — partly because the person has taken the drug for years and does not connect it to a recent change.
Why it is easy to miss
Cognitive side effects often develop gradually, or emerge when a dose changes, when kidney or liver function changes with age, or when a new medication is added and interacts with an existing one. Polypharmacy — taking multiple medications — increases the likelihood substantially, and is common in older adults.
Older adults are also more sensitive to a given dose. Changes in body composition, metabolism and the blood-brain barrier mean a dose tolerated at fifty may not be at seventy-five.
Classes with recognised cognitive effects
The following are discussed in clinical literature and prescribing guidance. Inclusion here does not mean a medication is inappropriate — many are prescribed because the benefit outweighs the risk.
- Anticholinergics. A large category acting on acetylcholine, a neurotransmitter central to memory. Includes some medications for overactive bladder, some antidepressants, some antipsychotics, some drugs for Parkinson's disease, and some antihistamines. Cumulative anticholinergic burden across several medications has been associated in research with cognitive effects.
- Benzodiazepines and related sedative-hypnotics. Used for anxiety and sleep. Can impair memory formation directly, and are associated with falls in older adults.
- Opioids. Can affect attention, sedation and memory, particularly at initiation or dose increase.
- Some antiepileptic drugs, with effects varying substantially between agents.
- Sedating antihistamines, including some available over the counter and some marketed as sleep aids. Many first-generation antihistamines have anticholinergic properties.
- Some medications for overactive bladder, where alternatives with lower anticholinergic burden may exist.
- Corticosteroids, which at higher doses can affect mood, sleep and memory.
Other classes are discussed with more mixed or contested evidence, including statins and proton pump inhibitors. For statins in particular, the evidence overall does not support avoiding them for cognitive reasons, and the cardiovascular benefit is well established — which matters because cardiovascular health is itself tied to cognitive health.
Indirect routes
Some medications affect memory indirectly. Long-term metformin use and long-term acid-suppressing medication have both been associated with reduced vitamin B12 absorption, and B12 deficiency can cause cognitive symptoms. That is a monitorable and correctable issue rather than a reason to stop.
Anything that disrupts sleep or causes daytime sedation will affect memory through that route, regardless of its direct pharmacology.
How to run a medication review
- List everything, including over-the-counter drugs, supplements and herbal products. These are frequently omitted and frequently relevant.
- Note when each was started, and whether cognitive changes began around a start or dose change.
- Ask specifically: is any of this contributing, and is there an alternative with less cognitive burden?
- Pharmacists are well placed for this and are often more accessible than a physician appointment.
- Ask about deprescribing — whether anything is no longer needed. Medications frequently continue long past the indication that started them.
The balance to hold
Untreated depression, untreated pain, untreated anxiety and untreated seizures all have their own cognitive and health consequences, often worse than the medication's. The goal is the right medication at the right dose, not fewer medications.
This is also why self-directed stopping is the wrong response to this article. Bring the list to a professional.
This article is general educational information, not medical advice. It cannot account for your medical history, medications or symptoms. Talk to a licensed physician before changing anything about how you manage your health, and see one promptly if you are worried about your memory. Read our full medical disclaimer.