Aging is a beautiful part of life. Most humans strive to age and to do so gracefully. With advances in science, medicine, and our overall understanding of the human body, older adults have many tools to use to live long, healthy lives. These tools are, however, are not fool proof.

One of these imperfect tools is medication. Both prescription and over the counter medicines can be wielded to extend the length and quality of life. Medication can prevent strokes and improve mood and relieve pain. The benefits of medication are always weighed by risks, and often times these risks not as well defined in older adults. When new medications are developed, they are often only tested for safety and effect in younger to middle aged adults. The side effects and risks that are known to a medication have often not been as closely evaluated in older adults. This means that some risks we may consider to be minor in younger individuals could actually be extremely significant and detrimental in older adults.

Luckily, there are a few ways for scientists and medical professionals to better understand the risks of medications in older adults. Some medications have gone through additional testing and observation in older adults. In others, scientists and medical professionals can use their understanding of how the body changes as humans age to predict how medications will change. Here are a few examples of common changes that occur in aging bodies and how these changes can alter the risks of medications in older adults:

The brain becomes less protected from toxins and medications.

Humans can be exposed to many medications and toxins throughout their lives. To protect the brain from these medications and substances, the body builds a barrier between the brain and the rest of the body. This barrier tends to become weaker as the body ages. As the barrier weakens, more medications and toxins come into contact with the brain and can cause side effects such as sedation, confusion, and delirium. There are many medications that cause very minimal effects on the brain in middle aged adults but can cause significant mental changes in older adults. Essentially ALL medications have potential to affect the brain in older adults. Here are some medications that are notorious for causing significantly more sedation and confusion in older adults:

  • Opioid pain medications such as hydrocodone, codeine, and oxycodone
  • Anti-anxiety medications like Ativan (lorazepam), Xanax (alprazolam), and Valium (diazepam)
  • Muscle relaxants like Flexeril (cyclobenzaprine) and Robaxin (methocarbamol)
  • Medications to help with sleep like Ambien (zolpidem)
  • Some antidepressants like Paxil (paroxetine) and Elavil (amitriptyline)
  • Some allergy medications like Benadryl (diphenhydramine)
  • Some bladder control medications like Oxytrol (oxybutynin) and Detrol (tolerodine)

The kidneys cannot get rid of medications and toxins as quickly

The kidneys play a very important role in removing toxins and medications from our bodies. As humans age, their kidneys naturally become slower at removing these things from the body. By the time a person reaches age 75-80, nearly 50% of their kidney’s ability to clear out old medication is gone. This can result in medications sticking around in the body for longer than they are supposed to and building up in the blood stream and causing problems. Here are two specific examples of what can happen when the kidneys slow down while using different types of medications

  • Blood thinners like Coumdin (warfarin), Eliquis (apixaban), and Xarelto (rivaroxaban) can build up in the body and increase risk of bleeding.
  • Blood sugar lower agents like Glynase (glyburide) and Amaryl (glimepiride) can build up in the body and cause blood sugar to go too low. Very low blood sugar can cause someone to faint, fall, and, in extreme cases, go into a coma.

The body cannot adjust to changes in blood pressure as quickly

Maintaining blood pressure is important for pumping blood to all parts of the body. When someone goes from a sitting or laying position to standing, their body must work against gravity to pump blood to the brain. As humans age, the body gets slower at adjusting blood pressure when changing positions. The result is feeling a “head-rush” or dizziness upon standing. This can increase risk of falls and can especially be an issue when older adults get up from bed to use the bathroom at night. Thus, it is important to monitor blood pressure and pay attention to signs of dizziness and feeling faint when older adults are on medications that alter blood pressure including the following:

  • Blood pressure medications, especially when taking multiple blood pressure medications at the same time (i.e. lisinopril, losartan, metoprolol, amlodipine, hydrochlorothiazide, nifedipine)
  • Some antidepressants like Paxil (paroxetine) and Elavil (amitriptyline)
  • Some medication to help with bladder control like terazosin and Flomax (tamsulosin)


These three changes only scratch the surface of what occurs in the body as it ages. It is also important to remember that everyone ages in different ways and at different rates. The older humans get, the more different they become.

So how can this information be used to prevent the risks of medications from outweighing their benefits?

  1. Be aware that these changes happen slowly and over time. Often, an aging person will be on a medication for many years without the slightest side effect before the changes in the body are significant enough to cause a difference. Do not assume that just because you have tolerated a medication well enough in the past means it will be safe indefinitely.
  2. Constantly re-evaluate the risks with the benefits of staying on a medication.
  3. If a decision is made to continue using a high-risk medication, be vigilant about looking for early signs that there could be a developing problem.
  4. Speak to a pharmacist or other health care provider before starting any new medication, even if you can buy it without a prescription. Many over the counter products contain high risk medications for older adults.
  5. Use only one pharmacy so that the pharmacist can review the drug interactions and added risks of all the

    medications being used.


Understanding how the body ages can help predict how medications will either help or hinder in aging process.

Consistently re-evaluating health and quality of life goals will enable and empower you to live your best life on your terms.

As Betty Friedan said,

“Aging is not ‘lost youth’ but a new stage of opportunity and strength.”


For more information and details please see the following references:

American Geriatrics Society 2019 updated AGS beers criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc. 2019 Apr;67(4):674-694. PMID: 30693946

Thurmann PA. Pharmacodynamics and pharmacokinetics in older adults. Curr Op in Anaest. 2020 Feb;33(1):109-113.

Beers MH. Aging as a risk factor for medication-related problems. The Consultant Pharmacist. 1999 Dec. Accessed from