Drug safety

Taking multiple medications can put you at risk


A close-up of someone’s hand opening a pill box at a breakfast table.

If you are taking several medications at the same time, you should know that certain combinations might cause unwanted and even harmful side effects. According to an article published in the Expert Opinion on Drug Safety journal, this problem is particularly serious for older people.1

The number of people 65 years and older is steadily growing, which has caused an increase of polypharmacy or persons taking 5 or more medicines or taking more medications than are medically necessary. Studies show that older adults taking 5 or more medications run an 88% higher risk of what’s called an “adverse drug event” than people who take fewer medications.1 An adverse drug event is defined as “an injury resulting from medical intervention related to a drug, including medication errors, adverse drug reactions, allergic reactions, and overdoses.”2

Some of these medicines include mental health drugs, opioids and even some allergy medicines. For a full list of these higher risk drugs, please review the chart to see if you’re taking any of these medicines.

Some of the problems associated with taking multiple medications include:

  • Falls
  • Cognitive impairment—in other words, trouble thinking, such as memory loss, dementia or delirium
  • Difficulty performing everyday tasks
  • Urinary incontinence
  • Poor nutrition
  • An inability to keep track of the correct timing and dosage of the various drugs
  • An increase in medical costs due to injuries and emergency room (ER) admits caused by side effects
  • Overdose—which may lead to heart issues or even death

Talk to your doctor or pharmacist if you are concerned about the drugs you are taking, and keep your doctors and pharmacists informed about all the drugs you take.3


Here’s a table of the most commonly prescribed medications that should be used with caution when taken together. 4,5

Most commonly prescribed anticholinergic medications*
Medication name Type of medication Potential risks with these combinations Paroxetine Antidepressant Cognitive impairment and increased risk of dementia Amitriptyline Antidepressant Cognitive impairment and increased risk of dementia Oxybutynin Bladder antispasmodic Cognitive impairment and increased risk of dementia Hydroxyzine Antihistamine Cognitive impairment and increased risk of dementia Cyclobenzaprine Muscle relaxant Cognitive impairment and increased risk of dementia Olanzapine Antipsychotic Cognitive impairment and increased risk of dementia Diphenhydramine Antihistamine Cognitive impairment and increased risk of dementia Meclizine Antihistamine (treats motion sickness) Cognitive impairment and increased risk of dementia Promethazine Antiemetic Cognitive impairment and increased risk of dementia

Most commonly prescribed central nervous system medications*
Medication name Type of medication Potential risks with these combinations Olanzapine Antipsychotic Falls and fractures and potential for overdose Aripiprazole Antipsychotic Falls and fractures and potential for overdose Quetiapine Antipsychotic Falls and fractures and potential for overdose Risperidone Antipsychotic Falls and fractures and potential for overdose Alprazolam Sedative Falls and fractures and potential for overdose Clonazepam Sedative Falls and fractures and potential for overdose Diazepam Sedative Falls and fractures and potential for overdose Lorazepam Sedative Falls and fractures and potential for overdose Zolpidem Sedative Falls and fractures and potential for overdose Hydrocodone Narcotic Falls and fractures and potential for overdose Tramadol Narcotic Falls and fractures and potential for overdose Oxycodone Narcotic Falls and fractures and potential for overdose Morphine Narcotic Falls and fractures and potential for overdose Codeine Narcotic Falls and fractures and potential for overdose Fentanyl Narcotic Falls and fractures and potential for overdose

*Definitions

Anticholinergic medications block the neurotransmitter acetylcholine in the central and peripheral nervous system. These medications includes some antihistamines, antidepressants and medications for gastrointestinal and bladder disorders.6

Central nervous system (CNS) medicines are responsible for processing and controlling most of our bodily functions. The CNS consists of the nerves in the brain and spinal cord. There are different types of medicines that work on the CNS including narcotics/opioids, sleep medicines and antidepressants.7

Sources

  1. Robert L. Maher et al., “Clinical Consequences of Polypharmacy in Elderly,” Expert Opinion on Drug Safety, 13, no. 1 (January 2014): 57–65, accessed August 6, 2019, doi:10.1517/14740338.2013.827660, opens new window. See also www.ncbi.nlm.nih.gov/pmc/articles/PMC3864987/, opens new window
  2. “Overview: Adverse Drug Events,” Health.gov, last accessed August 6, 2019, health.gov/hcq/ade.asp, opens new window.
  3. “Polypharmacy Concerns and Risks,” Verywell Health, last accessed August 6, 2019, www.verywellhealth.com/what-is-polypharmacy-2223450, opens new window.
  4. American Geriatrics Society 2015 Beers Criteria Update Expert Panel, et al. "American Geriatrics Society 2015 updated Beers criteria for potentially inappropriate medication use in older adults." Journal of the American Geriatrics Society 63.11 (2015): 2227-2246, https://doi.org/10.1111/jgs.13702, opens new window
  5. The American Geriatrics Society Beers Criteria Update Expert Panel. American Geriatrics Society 2019 Updated AGS Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. Journal of the American Geriatrics Society 00:1-21, 2019, https://doi.org/10.1111/jgs.15767, opens new window
  6. “Anticholinergic Drug Exposure and the Risk of Dementia: A Nested Case-Control Study,” JAMA Internal Medicine, 179, no. 8 (2019): 1084–1093, accessed August 6, 2019, doi:/10.1001jamainternmed.2019.0677, opens new window.
  7. Merriam-Webster’s Medical Desk Dictionary, 2002 Revised Edition.

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