Herbal-Drug Interactions Important in Dentistry, 2nd edition

Course overview

The use of plants for healing purposes and the knowledge required for their use (pharmacognosy) predates written human history and forms the origin of much of modern medicine. Many conventional drugs originate from plant sources, in fact, a century ago, of the few effective drugs that were available, most were plant-based. In 1870, the U.S. Pharmacopeia listed 636 herbal entries, the 2018 edition listed 26 herbal entries (U.S. Pharmacopeial Convention, 2018). Although some of these original herbal entries were found to be unsafe, most were replaced by pharmaceuticals derived from the original botanical medicines. Examples include aspirin (from willow bark), digoxin (from foxglove), quinine (from cinchona bark), and morphine (from the opium poppy). The development of drugs from plants continues, with drug companies being engaged in large-scale pharmacological screening of herbal substances. In the United States and Europe, however, over-the-counter natural herb products constitute a rapidly growing market, having joined prescription and over-the-counter medicines that were originally derived from herbs. Interest in herbal medicine has been facilitated by multiple factors, including the perception that pharmaceutical medications are expenHerbal medicines now fall into the category of complementary and alternative medicines (CAMs). Herbal supplements are receiving increasing exposure through national media, in lay journals, and more recently in the scientific press. Although the growth of the herbal medicine industry in the United States can probably not continue indefinitely at its current accelerated pace, there is little indication of any major slowing. Therefore, many patients will continue to use herbal medications. In fact, one survey conducted in the United States found that an estimated 12.3 million adults (5.4% of the population) used alternative therapies as a substitute for costly prescription medications (Wang, Kennedy, & Wu, 2015). According to the 2012 National Health Interview Survey, 33.2% of U.S. adults used complementary health approaches. This percentage is similar to the percentages in 2007 (35.5%) and 2002 (32.3%; National Center for Complementary and Integrative Health, Introduction - xii Herbal-Drug Interactions Important in Dentistry 2016). In addition, a federally funded National Health Statistics 2016 report (Nahin & Barnes, 2016) revealed that Americans spend up to $34 billion per year on CAMs. With the increasing popularity of CAMs, a new issue has arisen - herbal-drug interactions, of which oral healthcare professionals (OHCPs) must be aware. A survey of patients with heart disease, diabetes, psychiatric disorders, and/or hypertension found that 79% were taking supplements concurrently with prescription medications (Graham et al., 2008). Among those with cardiac disease, 20% reported regular use of herbals. About 16% of patients with diabetes and 16% of patients with psychiatric disorders reported regular use of CAMs. The results of this survey underscore the prevalence of herbal supplement use and the potential for herbal-drug interaction (Graham et al., 2008). Thus, the OHCP needs to be increasingly aware not only of these products effects and advantageous synergies, but also of their side effects and possible or probable adverse drug reactions. After completing this basic-level course, the learner will be able to discuss the most commonly used herbal medicines in the United States. A stoplight approach to risk assessment is discussed and a general strategy to avoid the most common herbal-drug interactions is suggested. Critical patient populations are emphasized and specific herbal-drug interactions that can lead to increased bleeding, decreased blood glucose levels, and sedation changes are discussed. This course is specifically designed for all members of the dental healthcare team - dentists, dental hygienists, and dental assistants.