By Peter Koukoumanos, MBA, PharmD Candidate 2025
Over the counter (OTC) medications are everywhere; lining store aisles, advertised on TV, and recommended by friends and family. It is a common misconception that they are completely safe as they do not require a prescription. But the reality is that OTC medications can carry risks, especially when misused, combined incorrectly, or taken without proper guidance.
Pharmacists play a key role in helping patients navigate OTC medication safety, and today, I want to share a few important tips to keep in mind the next time your patients reach for an over-the-counter med.
Common OTC Medication Mistakes (That Happen More Than You Would Think)
Taking Multiple Medications with the Same Active Ingredient
This is one of the most common and dangerous mistakes people make with OTC medications. Many products contain the same active ingredients, leading to accidental overdoses or increased risk of side effects.
For example, acetaminophen (the active ingredient in Tylenol) is found in many OTC remedies and products, from cough syrups to sleep aids. If someone takes Tylenol for a headache, plus a cold and flu combination medication, they might unknowingly exceed the recommended daily limit of 4,000 mg, putting themselves at risk for serious liver damage.
Always ask patients what other medications they may be taking at home and instruct them to look at active ingredients before taking multiple medications.
Thinking “More Is Better”
It is easy for patients to assume that if one dose of medication helps, taking a little extra will work even better. But doubling up on OTC meds can cause serious harm and sometimes not even make a difference in the symptoms they are trying to treat.
For example, nasal sprays like oxymetazoline (Afrin) used for more than three consecutive days can cause rebound congestion, making their symptoms even worse. For ibuprofen (Advil, Motrin), taking more than the recommended dose can lead to stomach ulcers, kidney problems, and elevated blood pressure.
Pain can be a complicated and frustrating issue to deal with. Many people assume that taking higher doses of ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) will provide better pain relief, but research shows that lower doses often work just as well but without the added risks.
Dr. Benton R. Hunter, MD, an Associate Professor of Clinical Emergency Medicine at the Indiana University School of Medicine, is one advocate of many for educating the public on proper medication use. In a research review in the New England Journal of Medicine, Dr. Hunter states:
“Since there is consistent evidence that doses above 400 mg do not provide additional pain control, we should avoid prescribing higher doses of ibuprofen.”
Although the research started in emergency departments, other studies have expanded their studies to general populations with similar results. However, it is important to note the limitation that these studies only measure pain treatment, as the anti-inflammatory effect of these medications may require higher dosing to be effective.
More is not always better. Stick to the recommended lower effective doses to manage pain safely. It is important to note that higher doses still do have their place for specific needs.
To stay safe, it is always recommended to follow the dosing instructions on the label and avoid using OTC meds longer than directed or needed.
Mixing OTC Medications with Supplements (or Prescription Meds)
Supplements and natural remedies seem harmless, but they can interact with OTC medications in surprising ways.
A few examples:
- St. John’s Wort is an herbal supplement that some people use to help with mood and depression, but it can be dangerous if combined with prescription antidepressants and can also reduce the effects of many other medications.
- Diphenhydramine (Benadryl, sleep aids) taken with alcohol or other antihistamines can cause extreme drowsiness and impairment.
- Pseudoephedrine (Sudafed) can raise blood pressure which is counterintuitive if also taking medication to lower blood pressure.
And let’s not forget that some prescription medications already contain ingredients found in OTC products and can lead to unintended interactions. Know what your patients are taking and how much of it.
Using Adult Medications for Children (or Guessing the Dose)
It can be tempting to break a pill in half or estimate a liquid dose when treating children. But kids are not just small adults, their bodies process medications differently than adults do. Additionally, there are many considerations to what kids should or should not be taking.
For example, aspirin can be an effective medication for adults, but it should never be given to children due to the risk of Reye’s syndrome, a rare but serious condition. And giving the wrong dose of ibuprofen or acetaminophen can either lead to toxicity or fail to treat a child’s fever effectively.
Instruct patients to choose pediatric formulations and always measure liquid medications with a proper dosing syringe instead of a spoon!
Why Independent Pharmacies Matter for OTC Safety
Large chain pharmacies and online retailers may sell OTC medications, but they likely do not provide the personalized guidance and care independent pharmacies like those in Cascadia Pharmacy Group can.
As pharmacists, we do not just fill prescriptions. It is very important that we also consider the following when advising a patient on their medications:
- Assess the patient’s current prescription and supplement regimen to identify potential interactions or duplications.
- Evaluate the appropriateness of the OTC product based on the patient’s symptoms, age, comorbidities, and organ function.
- Guide patients toward evidence-based, cost-effective options rather than popular or heavily marketed products.
- Recognize when OTC use might mask or delay diagnosis of a more serious condition and recommend follow-up with a provider when needed.
- Reinforce proper administration, dosing, and duration of use to prevent misuse or adverse effects.
Independent pharmacies focus on long-term relationships with patients. We take the time to educate customers, making sure they make informed choices about their health.
Pharmacists are your first line of defense when it comes to medication safety. Whether your patients need help choosing a cold medicine, managing chronic conditions, or just figuring out if a supplement is worth taking, we can help.
Reference:
Motov S, Masoudi A, Drapkin J, et al. Comparison of oral ibuprofen at three single-dose regimens for treating acute pain in the emergency department: a randomized controlled trial. Ann Emerg Med. 2019;74(4):530–537.
U.S. FDA. Mixing Medications and Dietary Supplements Can Endanger Your Health. Accessed March 11, 2025. https://www.fda.gov/consumers/consumer-updates/mixing-medications-and-dietary-supplements-can-endanger-your-health