Volume VIII, Number 1 | Spring 2024

What You Don’t Know Might Hurt You: Analysis of Patients’ Knowledge of Over-the-Counter Medication

Adam Rosen DO1; Audree Evans BS2; Jeffrey Wilde MD1
1Department of Orthopaedic Surgery, Scripps Clinic, La Jolla, CA
2Shiley Center for Orthopaedic Research and Education


Over the counter (OTC) medications like acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) are frequently used medications. Complications due to OTC medication can result in both the need for hospitalizations and occasionally death. Many patients are unaware of the dosages or risks associated with OTC medications. We aimed to test patients’ knowledge of common OTC medications that are used for pain and arthritis.

A test was created and given to patients who were new to our clinic presenting for a consultation for hip or knee pain. To validate the test, it was given to all six orthopedic attending surgeons, four orthopedic fellows, seven nurses, and five medical assistants within the total joint replacement division.

One hundred and six patients completed the 20-item test. The average score was 12.4 ± 4.0 (range, 5-20), which corresponded to an average score of 61%. Six attending surgeons completed the test; all scored 100%.  Four joint reconstruction fellows completed the test. The average score was 19.5 ± 0.5 (range 19-20), representing an average score of 97%. Seven registered nurses took the test. The average score was 19.6 ± 0.5 (range 19-20), representing an average score of 97%. Five medical assistants completed the test. The average score was 15.2 ± 3.8 (range, 10-20), representing an average score of 80%. 

Patients’ knowledge of OTC medications is poor, which places patients at risk for side effects and patient hospitalization.  

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently used to treat musculoskeletal complaints and other causes of pain. Although many NSAIDs are available over the counter (OTC), they still place patients at risk of adverse drug reactions (ADR). The United States Food and Drug Administration issued a public advisory in 2005 that “NSAIDs should be administered at the lowest effective dose for the shortest duration.” (1) 

Side effects from NSAIDs may include gastrointestinal (GI) bleeding, renal injury, and cardiac issues. It is estimated that 100,000 hospitalizations are due to GI complications due to NSAIDs. It has also been reported that approximately 16,500 deaths can be attributed to these drugs.(2) Many patients believe that OTC medications are safer than prescription drugs and studies have shown that patients routinely exceed recommended daily limits, and many are unaware of the risk of adverse drug reactions.(3-5) 
Acetaminophen, one of the most common pain killers, is also available OTC. While safe when used at appropriate doses it is one of the leading causes of liver damage. Many other products, such as OTC cold and flu remedies, as well as prescription narcotics, contain acetaminophen as a secondary ingredient. The further increases the risk of adverse drug reaction. Patients’ poor knowledge regarding dosages and side effects of acetaminophen place them at risk of exceeded daily limits and casing harm. (6-7) 

In our experience at our clinic, we found many patients had misunderstandings regarding the use of common OTC medications. Numerous patients did not know or had wrong information regarding dosage and the types of OTC medications that they were taking. Patients also frequently were unaware when OTC medications could negatively interact with prescriptions medications there were currently taking. Most patients had a poor understanding of the risks associated with OTC medications. 

Due to our observation of patients’ poor understanding of OTC medications and the potential risks of these drugs, we elected to test patients’ knowledge regarding the common OTC medications and their side effects. We created a novel twenty question true-false test to analyze patients’ understanding of commonly used OTC medications. We hypothed that patients would score poorly when their knowledge of OTC medications was tested. 

Materials and Methods
An IRB approved novel 20-question true-false test (supplemental file) was created by two orthopedic surgery attendings to test the knowledge of common OTC pain medications. The test was given to new patients when they presented for a consultation for either hip or knee pain in the orthopedic surgery department division of total joint replacement surgery with either of the two authors. Inclusion criteria were new patients, patients over the age of fifty, and that they were able to read and write in the English language. Patients were excluded if they were unable to read or write in the English language or had underlying conditions that prevented them from taking the test, such as dementia, Alzheimer’s, or other cognitive impairments, or if they refused to take the test. Returning patients and post-surgical patients were also excluded during the study period.

To validate the test, it was also administered to staff. All six joint arthroplasty attending surgeons, each of the four total joint replacement fellows, five medical assistants, and each of the seven registered nurses in the division of total joint replacement took the test.

All questions were true or false. Respondents were asked not to use their phone or other devices to help answer the questions. All tests were de-identified.

One hundred twenty-eight tests were administered to patients. Twenty-two patients started the test but did not finish. Incomplete tests were not graded or included in the analyses. One hundred six questionnaires were fully completed by the patients and included in the present analysis. The average score was 12.4 ± 4.0 (range, 5-20), which corresponded to an average score of 61%. Question nineteen specifically asked as to whether narcotics include Tylenol, 69% of patients (73 of 106) answered the question incorrectly. 

Six attending surgeons completed the test; all scored 100%.  Four joint reconstruction fellows completed the test halfway through their fellowship year of training. The average score was 19.5 ± 0.5 (range 19-20), representing an average score of 97%. Two of the fellows answered question four incorrectly. Seven registered nurses took the test. The average score was 19.6 ± 0.5 (range 19-20), representing an average score of 97%. Two of the nurses answered question six wrong. The five medical assistants that work in the division were given the test. The average score was 15.2 ± 3.8 (range, 10-20), representing an average score of 80%. 

Most people suffer from pain at some point in their lives. Pain is a common reason for people to use NSAIDs or acetaminophen. The CDC reports that there are over 58 million US adults with arthritis.8 Although health care practitioners may prescribe medications for the treatment of pain, many patients can purchase pain relievers OTC.

The American Gastroenterological Association (AGA) noted that 36 million individuals use OTC and prescription NSAIDs daily for arthritis, headaches, and other pains. Studies have shown patients are at risk of exceeding daily limits of NSAIDs more than twenty-five percent of the time.5,9 Other studies have found patients are frequently unaware of side effects and received insufficient information of potential risks of these medications. (5,10) 

The FDA has made numerous changes to the recommended daily dosage of acetaminophen due to the reports of liver failure. In 2011 the FDA instituted a limit to the amount of acetaminophen that could be added to prescription drugs that went into effect in 2014. This limited the amount of acetaminophen to be no greater than 325 mg. As many other OTC and prescription drugs contain acetaminophen, patients are still at risk of exceeding the daily limit. 

A study of emergency room patients found that more than half of the patients they queried did not know the daily limits of acetaminophen.6 The authors also found that the majority of the patients that they studied did not know that narcotics contained acetaminophen. This was similar to our study that demonstrated that 69% of patients were unaware that narcotics such as Percocet, Vicodin, and Norco contained acetaminophen.

It had been our experience that many patients would present to our clinic with a history of taking more than one NSAID at a time, exceeding the recommended doses of NSAIDs, or using NSAIDs when concurrently taking a prescription anticoagulant medication. Furthermore, patients using prescription narcotics would report using additional OTC acetaminophen commonly exceeding the recommended daily limit. 

Based on our experience, we designed this novel test to better evaluate our patients understanding of these commonly available medications. By administering the test to staff in the division of lower extremity reconstruction within the Department of Orthopedics, we felt that the distribution of the scores in the physicians, nurses, and medical assistants validated the reliability of the test. 

There are some limitations to the study. We de-identified the test so we are not able to draw any conclusions based on age, sex, or level of education. Another limitation is dealing with the interaction of OTC medications with anticoagulation medications (questions 10 through 13). It may have been helpful to identify patients that were using anticoagulation medications to get a better assessment of their risk and understanding of the potential drug interactions with OTC medications. High-risk patients using anti-coagulants should be coupled on the risks of using NSAIDs and may be recommended strategies to mitigate risk of GI injury. (11) 

We felt that the arthritic orthopedic clinic was a good patient population to test with our questionnaire as most of our patients present with pain and report using medication to treat their symptoms. In addition, our patients are typically over the age of 50, and are more likely to be on other prescription medications which increases the risk of a drug-drug interaction. Lanas et al. found that over 90% of patients with osteoarthritis were at increased risk of GI side effects. (12) 

Informed consent and patient education is paramount to prevent harm. Babelghaith et al. demonstrated that more than half of those studied would have made changes to the use of OTC with education from their physician. (10)  This shows that there is the potential, with education, to decrease the chance of side effects and drug related complications due to OTC medications. 

Our study found that a concerning number of patients have a poor understanding of common OTC medications which places them at risk for adverse drug reactions. As a result of this information, we have developed educational handouts and spend more time discussing risks, side effects, drug interactions, and appropriate dosages with patients. We would recommend that physicians, physician extenders, pharmacists, and manufacturers continue to educate patients to prevent the potential for harm.

Our study demonstrated that patients have poor knowledge of over-the-counter medications. Patients limited knowledge may be multifactorial. Causes may include the inability of health care practitioners to adequately educate patients, failure of drug manufactures to make side effects more transparent to people that use their products, and failure of the patient to read medication labels. Poor patient knowledge regarding the use of over-the-counter medications can lead to serious complications. It is our belief that widespread education and knowledge should be directed to patients who use these medications.

Figure 1

Required Disclosures and Declaration

Copyright Information: No Copyright Information Added
IRB Approval Information: Yes
Disclosure Information: Evans: None Wilde: Depuy Rosen: Amazon, Arvis, Barns & Noble, Innomed, Next Science


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The Journal of the American Osteopathic Academy of Orthopedics

Steven J. Heithoff, DO, FAOAO

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