Key takeaways:
Dietary and herbal supplements are commonly used by patients in the U.S. and throughout the world.
Despite their widespread use, dietary and herbal supplements still have limited scientific evidence on their quality, efficacy, and safety.
As medication experts, pharmacists are uniquely qualified to counsel patients on the safe use of dietary supplements.
Over-the-counter (OTC) dietary and herbal supplements are widely used in the U.S. and throughout the world. According to a CDC survey, around 58% of U.S. adults reported taking at least one dietary supplement in the past month.
Supplement use rises with age, with the highest reported use among women over 60 years of age (about 80%). The most used supplements reported were multivitamins, vitamin D supplements, and omega-3 fatty acids.
In another independent survey on patterns of medication use among U.S. adults, the most reported reasons for taking supplements were for general health and chronic conditions, such as arthritis and memory loss.
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In 1994, the Dietary Supplement Health and Education Act (DSHEA) placed dietary supplements in a separate category from drugs. Because they are not categorized as drugs, supplements are not subject to the same FDA regulations as conventional drugs. Supplements can be marketed without prior clinical trial evidence to show efficacy, safety, or quality of the products.
The FDA does regulate certain aspects of supplements though. The FDA’s Good Manufacturing Practices (GMPs) for dietary supplements require products to be properly labeled, free of impurities, and manufactured according to specified standards.
But, dietary and herbal supplements can be both beneficial and harmful. Here, we’ll discuss trends regarding the use of dietary supplements in the U.S. and how healthcare professionals can counsel patients regarding their use.
Having a discussion with patients about the use of supplements is essential to get a complete and accurate medication history. Many dietary and herbal supplements can have harmful side effects. But, knowing about their use allows pharmacists and other health professionals to consider possible drug interactions and adverse effects.
Patients often do not readily report their supplement use to their healthcare providers. One survey found that around one-fourth of patients using herbal supplements do not disclose the use to their healthcare providers. The most commonly reported reasons for nondisclosure were that the healthcare provider did not ask, or they thought it was not important information for their providers to know.
Possible safety risks of herbal and dietary supplements include drug interactions and adverse effects. And because dietary and herbal supplements are not subject to FDA regulations, there can be major differences in the quality of products which can affect the efficacy and safety.
The use of ephedra alkaloids is one notable example of possible adverse effects with herbal products. This product has been marketed in the past as a weight loss supplement in combination with caffeine. A review of adverse effects associated with ephedra use found episodes of seizures, hypertension, and myocardial infarction. Other effects included strokes and arrhythmias. Ten of the reported events lead to death. And, 13 events caused permanent disability. Because of these reports, the FDA banned the sale of products containing ephedra in 2004.
Data shows that some dietary and herbal supplements may possibly interact with drugs. One example is St. John’s wort. It’s a commonly used herbal product that is marketed for mental health conditions such as depression.
St. John's wort is known to trigger certain cytochrome P450 enzymes. These enzymes are responsible for metabolizing many drugs. This results in possible drug-herb interactions with medications, such as:
Cyclosporine
Warfarin
Digoxin
Oral contraceptives
Protease inhibitors
What’s more, because of its serotonergic (involving or affected by serotonin) nature, St John’s wort may raise the risk of serotonin syndrome. Especially, when it’s combined with other serotonergic medications.
Ginkgo biloba is an herbal product that is commonly used by patients for mental health conditions, memory loss, fatigue, and more. Because of its antiplatelet and antithrombotic effects, ginkgo biloba can interact with anticoagulants, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs). This can raise the risk for severe bleeding.
Getting a complete and accurate medication history includes reconciling both prescription and non-prescription products. As medication experts, pharmacists are uniquely qualified and equipped to counsel patients about their supplement use.
Patients may not readily give information on supplement use to their healthcare providers.
You can ask about the use of supplements during the medication history in a hospital or clinical pharmacy setting by asking open-ended questions. One question you can ask is "What prescription, over-the-counter medicines, vitamins, herbs, or supplements do you take currently?"
In a community pharmacy setting, you can ask during consultation with a patient at the point of purchase, in the consultation room, drive-thru, or even on the telephone. The technique and setting should be adjusted to meet the patient’s specific needs.
In a high-volume community pharmacy, multiple competing priorities and time constraints may be possible barriers. They make it hard to assess the use of dietary supplements and counsel patients appropriately. But, pharmacists and staff should prioritize offering quality patient care. This will help improve medication use and avoid drug-related problems.
One study published in the American Journal of Health-System Pharmacy evaluated the time requirements for pharmacists to counsel patients in a community pharmacy setting. The study found that it took about 3 minutes on average for a patient counseling encounter. And the time spent included discussions regarding side effects, duplicate therapy, or medication adherence. Discussions about drug interactions or medication appropriateness need an extra 30 seconds and 2 minutes, respectively.
For patients that report using supplements, pharmacists and other healthcare professionals should ask the patient which specific supplement they take and how they take it. Patients should also be asked about their reasons for using supplements.
Finding out the reasons why a patient uses a certain supplement may create opportunities for patients to talk about health concerns that could be better managed with more evidence-based therapies.
Scientific evidence on most supplement use is limited. So, patients should be told of the uncertainty of these products’ safety and efficacy. These discussions should be documented in the patient’s medical record or where appropriate. Patients should also be advised to consult with their healthcare providers before starting any supplements.
Pharmacists and other healthcare professionals should discourage the use of supplements with evidence of harm. These include things like adverse effects, drug interactions, or lack of quality. For patients who continue to use these products, clinicians should keep a nonjudgmental attitude. This will allow for continued monitoring and open communication.
But, supplement use may be clinically indicated in certain situations, such as for a known nutritional deficiency. It may be reasonable to recommend the use of a particular supplement if there is evidence for its quality, safety, and efficacy.
Certain independent organizations offer quality testing for dietary and herbal supplements, including US Pharmacopeia, National Sanitation Foundation (NSF) International, and Consumerlab.com.
Manufacturers can voluntarily submit for their products to be evaluated by these organizations for quality, accurate labeling, good manufacturing practices, and the absence of harmful contaminants. Supplement products that have been found to meet these standards have a seal of approval displayed on the labeling. Pharmacists should suggest the use of products that have this seal. But, it is important to know that the seal does not guarantee the product’s efficacy.
Dietary and herbal supplements are widely used in the U.S. and across the world — despite their possible harmful effects and limited evidence of efficacy. Healthcare providers should ask patients regularly about their supplement use. This will allow them to get a complete and accurate medication history. As medication experts, pharmacists are uniquely qualified to counsel and educate patients and caregivers on the use of dietary and herbal supplements.