Pharmacology is derived from the Greek prefix pharmaco-, meaning “drug” or “medicine,” and the Greek suffix -logy, meaning “study.” Therefore pharmacology is the study of drugs and their interactions with living cells and systems. Drugs are chemical substances that are used in the diagnosis, treatment, or prevention of disease or other abnormal conditions. They can be used in both humans and animals. Drugs include synthetically derived compounds, vitamins, and minerals as well as herbal supplements—although these last substances are marketed not as drugs but as food supplements. In addition to pharmacology, the dental hygienist should know about its related disciplines, as listed and defined in Table 1-1.
Disciplines Related to Pharmacology
|Area of Pharmacology||Definition|
|Pharmacotherapy||The use of medications to treat different disease states|
|Pharmacodynamics||The study of the action of drugs on living organisms|
|Pharmacokinetics||The study of what the body does to a drug; the measurement of the absorption, distribution, metabolism, and excretion of drug from the body|
|Pharmacy||The practice of compounding, preparing, dispensing, and counseling of patients about their medications|
|Toxicology||The study of the harmful effects of drugs on living tissues|
Pharmacology had its beginning when our human ancestors noticed that ingesting certain plants altered body functions or awareness. The first pharmacologist was a person who became more astute in observing and remembering which plant products produced predictable results. From this humble beginning, a huge industrial and academic community concerned with the study and development of drugs has evolved. Plants from the rain forest and chemicals from tar have been searched for the presence of drugs. The agents discovered and found to be useful are then prescribed and dispensed through the practice of medicine, dentistry, pharmacy, and nursing. Health care providers who can write prescriptions include physicians (for humans), veterinarians (for animals), dentists (for dental problems), and optometrists (for eye problems). Physicians’ assistants, nurse practitioners, pharmacists, and dental hygienists can prescribe drugs under certain guidelines and in certain states.
In today’s ever-changing health care environment, it is important that the dental hygienist know more than the name and color of a medication. Patients rely on the dental hygienist to provide them with the correct information regarding their medication and oral health care. Although, dental hygienists do not prescribe drugs, it is important that they have knowledge of pharmacology and its related disciplines in order to provide more effective care to the patient.
As a result of the many breakthroughs in medicine and pharmacy research, more and more diseases can be treated; therefore, more and more people are taking medication. More often than not the dental hygienist is the first health professional in the dental practice to assess the patient’s medication history. Obtaining a medication/health history is the first step in safely treating a patient. Patients may be taking any number of medications that interact with medications used in oral health care or that may adversely affect oral health. An understanding of the actions, indications, adverse reactions, and therapeutic uses of these drugs can help determine potential effects on dental treatment. Comparing the medical conditions of the patient with the medications he or she is taking often raises questions in the interview. Examples include the risk of xerostomia in patients taking calcium channel blockers for hypertension and the increased risk of gingival bleeding in patients taking an aspirin each day to prevent a heart attack or stroke. A detailed health/medication history allows the dental hygienist to provide the best possible health care to the patient (Box 1-1).
Because the dental hygienist administers certain drugs in the office, knowledge of these agents is crucial. For example, the oral health care provider commonly applies topical fluoride, and in some states, both the dentist and the dental hygienist administer local anesthetics and nitrous oxide. In-depth knowledge of these agents is especially important because of their frequent use.
The ability to recognize and assist in dental emergencies requires knowledge of certain drugs. The indications for these drugs and their adverse reactions must be considered. For example, in a patient having an anaphylactic reaction, epinephrine must be administered quickly.
Patients taking medication for systemic diseases may require special handling in the dental office. For example, asthmatic patients who experience dental anxiety should schedule their appointments when they are not rushed or under pressure early in the morning in order to avoid an asthma attack. Whereas diabetic patients usually have fewer problems with morning appointments schedule 90 minutes after meals and medication administration. Certain patients may need to take medication before their appointments. Patients with a history of infective endocarditis need to be premedicated with antibiotics before some of their dental or dental hygiene appointments.
More and more patients are self-treating with nonprescription drugs. Also, nonprescription or over-the-counter (OTC) products may be recommended for the patient. The study of pharmacology will assist the oral health care provider in an intelligent selection of an appropriate OTC product. Although patients tend to forget that OTC products are drugs, knowledge of pharmacology will allow the dental hygienist to evaluate the patient for therapeutic OTC drug effects and adverse effects.
Many patients self-treat or are prescribed nutritional or herbal supplements for any number of disease states. Although the vast majority of these supplements do not carry U.S. Food and Drug Administration (FDA) approval for treating disease states, patients still use them. These supplements are drugs and can cause adverse effects and interact with other drugs.
Many different medications are available, and it is important for the dental hygienist to know where to look for information about prescription medications, nonprescription medications, and herbal supplements. There are many sources, including reference texts, association journals, and the internet, where pertinent drug information can be found. Box 1-2 reviews the different sources of information.
Each publication type can be selected according to its lack of bias, its publication date (when the current edition was released), its readability (vocabulary, simplicity of explanations, and presence of visual aids), its degree of detail (all you want to know and much more, just the right amount of information, or not enough to understand what is being said), and its price. Some publications are specific for disease states, geriatric or pediatric patients, drug interactions, or prescription drugs or nonprescription drugs. Reference books can be updated monthly, quarterly, and annually. Every dental office should have at least one reference book that lists the names of both prescription and OTC drugs. Further, a standard pharmacology textbook would be helpful in understanding the reference books. Because of the continual release of new drugs, a recent edition (not more than 1 or 2 years old) of a reference book is needed.
Although books serve as the usual source of information on drugs, many health care providers are using electronic resources, such as computer software and Internet-based services. Computer tablets and smart phones are also being used more and more for recording and storing patient information, calculating drug doses, and consulting medication information databases. Many online resources are available; they include Davis’s Drug Guide (www.drugguide.com/ddo/), Epocrates (www.epocrates.com), and Lexicomp (www.lexicomp.com