The Over-the-Counter Drug Conundrum


It is imperative for oncology nurses to know about all the drugs and supplements that their patients are taking.

Having a longstanding interest in cancer in the elderly, I have maintained a keen eye on the literature focusing on polypharmacy, since older adults are most at risk for this phenomenon. Case in point, for each chronic illness, a drug—or maybe 2 or more — is usually prescribed. Thus, when an older adult is subsequently diagnosed with cancer, they may already routinely be taking 4 to 6 medications for conditions such as hypertension, diabetes, arthritis pain, or coronary artery disease. This then is compounded by the addition of cancer-related medications which may include oral antineoplastics, drugs to manage adverse events, and other supportive care drugs. The number can grow even higher as many patients do not tell us when they are taking over-the-counter drugs or herbs and botanicals.

Many years ago, I heard a geriatrician speak on elder pharmacologic issues. He offered some advice that, for me, prevails to this day. He cautioned, “Every time you see an older person have an unusual symptom experience, namely an exaggerated presentation, or an unexplained response to a medication, consider the possibility that the patient is consuming over the counter (OTC) drugs that they have not told you about.”

In a quality improvement project I spearheaded years ago on delirium in older hospitalized patients with cancer, I realized the prominence of this phenomenon.

Family members of patients who were admitted to the oncology unit with delirium were questioned about what the patient had been taking at home before their admission. In almost all instances, the patients were self-medicating themselves with OTC drugs having anticholinergic effects known to cause cognitive impairment in the elderly. Additionally, the average number of drugs they were consuming was 12 daily.

The majority of Americans who use OTC drugs are over age 65.1 Additionally, it is estimated that one-thirds of patients with cancer take some type of supplement.2 Unknown to the lay consumer is the fact that just because these drugs can be purchased without a prescription, does not mean they are without deleterious effects.

Dietary supplements and OTC medications may have pharmacologic effects similar to prescription drugs. When taken together, there is the possibility that increased adverse events may occur. For example, when taking a prescription medication for sleep or anxiety in addition to supplements such as chamomile, kava, lavender, or valerian, increased drowsiness or sedation may result. This might be observed in an older patient with lymphoma complaining of difficulty sleeping. After being prescribed a hypnotic at bedtime, the patient then can have difficulty becoming aroused in the morning. Also, supplements taken for a non-cancer condition may have deleterious effects on the patient’s physical status. A good example of this is when patients take chondroitin, glucosamine, or turmeric for osteoarthritis. These supplements can have antiplatelet and anticoagulant properties which increase the patient’s risk for bleeding.

In meeting with newly diagnosed patients, it is imperative that they are given the message that the treatment team needs to know about all prescription and non-prescription drugs and supplements they are consuming. One approach is the “Brown Bag” request, asking new patients to bring all drugs and supplements they are consuming for a medical condition at the start of treatment.

An excellent resource I have found for nurses and patients is the website www.mskcc.aboutbotanicals/herbs where one can search information about non-prescription supplements inclusive of their potential interactions with prescription medications and research findings about their efficacy. I strongly suggest that this evidence-based resource be made available to all our patients.


1. Qato DM, Alexander DC, Conti RM Use of prescription and over the counter medications and dietary supplements among older adults in the United States. JAMA, 2008 300(24): 2867-2878.

2. Farina EK, Austin KG, Lieberman HR. Concomitant dietary supplement and prescription medication use is prevalent in US adults with doctor-informed medical conditions. J Acad Nutr Diet, 2014. 114: 1784-1790.

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