Medicines and Cognitive Impairment

One of the hardest things I’ve found about being a pharmacist is controlling my tendency to be nosey about medications. I don’t look in anyone’s medicine cabinet, but I am always ready to ask, “… and what medicines are you taking?” Nowhere is my curiosity harder to control than when I encounter older patients with cognitive issues.

Cognitive impairment represents a continuum from normal functioning to full dementia. Mild cognitive impairment presents as a noticeable decline in mental function in areas such as attention, learning, memory, problem solving and/or language processing and might include minor symptoms from not being a fast you’d like to more complex presentations that make it hard to function. Some changes in mental functioning are considered a normal part of aging; others, such as Alzheimer’s Disease are what many aging patients and their families worry about.

But when someone mentions a loved one who suddenly experiences cognitive impairment, I don’t immediately think Alzheimer’s Disease and progressive dementia. Instead, I ask “… and what medicines might they be taking?

Among the medicines that can diminish mental function are a number of prescription and nonprescription medications. Medications that can decrease mental efficiency include:
• opioids used for pain, as well as other pain medications
• benzodiazepines, such as alprazolam and lorazepam, used for anxiety or sleep
• some medications used for seizures or for chronic pain
• some medications used to treat cancer or HIV
• some medications used for blood pressure
• some medications used for bladder control
• many antihistamines.

It’s interesting that many of these medications share a similar type of pharmacologic activity, called “anticholinergic”. Some of the drugs used to improve mental function in Alzheimer’s Disease target the opposite effect by enhancing cholinergic function.

What should you do if you think medicines might be contributing to mental decline? Do NOT stop taking your medicines. First, speak with your pharmacist or prescriber. Come prepared with a list of all prescription nonprescription and dietary supplements. Be prepared to answer questions about symptom timing (when is it worse or better?) and to identify anything that makes your symptoms better or worse. Thorough medication reviews by pharmacists can identify a variety of drug-related problems.

If your medicines might be contributing to mental impairment, your prescriber or pharmacist may suggest changes to your medicines. It may be possible to switch to another medication that does not affect your mental function. If you are taking medicines for symptomatic relief – such as pain meds or antihistamines – you might decide to tolerate more of those symptoms so that you’ll have less mental fogginess.

Often a change in dosage or timing can help. Sometimes patients experience effects such as mental fogginess shortly after taking a medicine. It may be as simple as a switch to a sustained-release formulation. If the medicine is taken once daily, your prescriber or pharmacist might suggest that you take it before bedtime so that you sleep through the time when you would experience fogginess.

Medicines are not always responsible for poor memory or disorientation or getting lost easily, and medicines are not the only thing that can help. Exercise is recommended and appears to help mental function in many patients who are able to exercise. Some patients may be experiencing early signs of progressive dementia, but rather than ignoring these as a sign of aging, it is best to check your medicines with your pharmacist or prescriber and to remain as active as practicable.

Medication reviews can help patients who experience any side effect or adverse effect with their medications. Many health plans cover medication review for patients with serious disease states or those on multiple medications. Make friends with your clinic or community pharmacist and ask about your medications.

References

Petersen, RC et al: Practice guideline update summary: Mild cognitive impairment. Neurology 90:126-135 (2018).
Risacher SL et al: Association Between Anticholinergic Medication Use and Cognition, Brain Metabolism, and Brain Atrophy in Cognitively Normal Older Adults. JAMA Neurol. 73(6):721-732 (2016).

Splinter MY: Cognitive Disorders. In Drug-Induced Diseases Prevention, Detection and Management, Second Edition. Ed by Tisdale, JE and Miller DA. American Society of Health System Pharmacists (2010).