1.2 Drug Sources, Forms, and Names

Drug Sources and Forms

Drugs are substances or compounds that prevent, treat, diagnose, or cure various conditions or diseases. As mentioned previously, drugs come from a variety of resources—plants, animal products, and inorganic substances. Ideally, these chemicals have desirable therapeutic effects without harmful properties, although many derivatives may have poisonous effects, depending upon the dosage used. Some plant-based products in use today include digitalis from the foxglove plant, vincristine from the periwinkle, and morphine from the poppy plant. The Amazon Basin is home to countless numbers of plants with medicinal properties. Though not in use today, one of the first paralytic agents used in anesthesia was curare, made from a vine known as Chondrodendron tomentosum, found near the Amazon River in South America. The Indigenous population in the area placed a curare mixture on the tip of blow darts and used it for hunting (see Figure 1.3). The prey is paralyzed once curare enters the bloodstream; however, the meat is safe to eat because it is not toxic when eaten and digested.

Figure 1.3 One of the first paralytics used in anesthesia was curare, which Central American, South American, and Caribbean hunters used to coat blow darts. (credit: “Blow gun darts tipped wih curare from South America”/Wellcome Collection, CC BY 4.0 International)

Some medications come from animals and animal products, including the human body. This list includes a few common medications derived from animals or animal products, though it is not all-inclusive. Heparin and enoxaparin, anticoagulants used to prevent or treat blood clots, are made from pig intestines, and some thyroid medications and pancrelipase are also porcine derivatives. Conjugated estrogens, used to treat menopausal hot flashes, are made from the urine of female horses. Exenatide, used to treat type 2 diabetes, can be made from the saliva or venom of the Gila monster, which is a venomous lizard native to the southwestern United States and northern Mexico. Other drugs come from chicken eggs or yeast.

Several medications, such as vaccines, antivenins and antitoxins, hormones, and monoclonal antibodies, are known as biologics. Biologics are medications that come from a living source and are developed through a combination of biomolecular science, immunology, and genetic engineering. Gene-based therapies are another example of cutting-edge research in the world of biologics. They show great promise in treating some cancers and other conditions that currently have no available treatments. They are produced through biotechnological processes, some of which may have unique drug-delivery systems (Atkinson, 2022). Biologics offer the advantage of more targeted therapy for specific diseases, such as autoimmune disorders and cancer, with the potential for fewer side effects, but they are uniquely formulated with complex pharmacotherapy and may require administration through infusions or injections, which adds to the cost of treatment. Monoclonal antibodies, exemplified by etanercept (Enbrel), a biologic, have revolutionized the treatment of diseases like rheumatoid arthritis (RA). Formerly managed with drugs like methotrexate and corticosteroids, known for their severe adverse effects, monoclonal antibodies now offer a more favorable and less toxic treatment option for RA.

One of the primary drawbacks to the use of biologics is their expense. These drugs take more work to purify, process, and produce, and many are given through infusions or injections. As their patents expire, however, biosimilars may be produced. Biosimilars are synthetically produced drugs with similar properties, including mechanism of action and dosing, to those of a biologic. Generally, this allows a biosimilar drug to be produced at a reduced cost than the equivalent biologic drug. Biosimilars are effectively a means to improve the access to biologics while decreasing the cost of therapy.

Biosimilars differ somewhat from generic drugs. The development of biosimilars may take as long as 10 years and cost close to $100 million (Pfizer, 2021). Generic medications are much less costly ($1–2 million) and may be developed over only a couple of years. However, the essential difference between a biosimilar and a generic medication is in the drug’s molecular structure. Biosimilar drugs have a larger and more complex molecular structure than generic drugs and are made from a living organism such as yeast or bacteria (U.S. Food and Drug Administration [FDA], 2022c). They are not bioequivalent, however, because of the complex manufacturing processes involved. A brand biologic may be produced using a specific cell line or protein to yield the molecule, which is not available to the maker of the biosimilar. They must come up with their own manufacturing process to create a molecule that is very similar. A company manufacturing a generic drug has to demonstrate that the drug is bioequivalent to the brand-name drug, whereas a company developing and producing a biosimilar drug must demonstrate that it is similar to the biologic it is patterned after (called the reference drug). (See more about generic drugs a little later in this chapter.)

Chemical compounds produced in a laboratory either commercially by a drug manufacturer or illegally by individuals producing drugs for illicit reasons are called synthetic drugs. The first synthetic drug, a sedative-hypnotic drug known as chloral hydrate, was first used in medicine in 1869. Sometimes scientists will genetically engineer bacteria or slightly alter the chemical structure of substances to produce chemicals that are therapeutic. A small change in the chemical structure of some medications may make them more helpful than they previously were—they may become more potent or have fewer side effects—making the new compound much more desirable. Often individuals have fewer allergic reactions to synthetic drugs.

Many drugs come from inorganic compounds. Inorganic compounds are often salts from chemical components that have been found to have therapeutic effects. Aluminum and magnesium compounds are helpful in the treatment of indigestion, constipation, or diarrhea. Fluoride and iodide strengthen the enamel on teeth and prevent cavities. Iron helps treat iron-deficiency anemia.

Drugs come in many forms, but there are three primary categories for their routes of administration:

1. Percutaneous administration: The application of medications to the skin or mucous membranes
2. Enteral administration: The administration of medications into the gastrointestinal (GI) tract
3. Parenteral administration: The administration of drugs somewhere other than the GI tract (usually this means by subcutaneous, intramuscular, intradermal, or intravenous injection)

Drug forms in the percutaneous category include creams, topical ointments, powders, dressings (such as those used for wound care), and transdermal patches or disks. Other drugs in this category include eye, nose, or ear drops; vaginal medications; and aerosolized liquids that are inhaled and can be absorbed in the lungs. Some drugs in this category are able to deliver the medication in a constant amount over a specific time frame. The therapeutic effects may last longer depending upon the delivery method.

Enteral medications are drugs administered into the gastrointestinal (GI) tract. This can be done orally, rectally, or through a tube in the GI tract. The most common forms for these routes are through capsules and tablets (both may be sustained release), caplets, elixirs, emulsions, lozenges, suspensions, and syrups. The onset of action of these preparations will vary depending upon the form of the drug. Time-release capsules or tablets and enteric-coated tablets should not be crushed or chewed. Generally, these capsules should also not be opened and emptied onto food because this will alter how quickly the drug is absorbed. Note that some formulations can be opened in this manner, but it is best to ask before attempting this. An overdose of medication could result, although a subtherapeutic dose could also result from opening the capsule.

The parenteral route commonly refers to drugs given by injection, though parenteral literally means “outside the GI tract.” The onset of action is often more rapid than with oral administration; however, the duration of action is usually shorter. Because these drugs do not have to travel through the stomach and be metabolized in the liver, the dose is usually smaller than with oral dosing. This route is often prescribed when it is necessary to deliver a drug quickly. It is also helpful when the client is experiencing nausea or vomiting. The drug form for parenteral medications is that of a liquid. There are no barriers to absorption for intravenous medications because these drugs are injected directly into the bloodstream—absorption is immediate and complete. Intramuscular injections and subcutaneous injections may be absorbed rapidly or slowly, depending upon the solubility of the drug and blood flow to the injection area. Drugs that are highly soluble in water are absorbed very quickly (10–30 minutes); however, poorly soluble drugs will be absorbed at a much slower rate.

Drug Names

One of the biggest challenges when learning pharmacology is that all drugs have multiple names and ways to be identified. There are three basic methods for identifying a drug—the chemical name, the generic name, and the brand name, or trade name. If more than one drug company supplies a drug to the market, then that drug will have more than one brand name. To further confuse things, these names may vary in different countries.

Chemical names are built around the drug’s specific chemical structure or composition. This name usually has little meaning for the nurse, though it does have meaning for the chemist or pharmacist. The chemical names are usually complex and quite hard to pronounce; for example, the chemical name for ibuprofen is 2-(4-Isobutylphenyl) propanoic acid. Most nurses will not use chemical names, though a few, like sodium chloride, which is easy to remember and pronounce, have made it into the nurse’s lexicon.

Generic names, also known as common names, are given by the U.S. Adopted Names Council. Often generic names are part of the chemical name’s structure, which helps identify and classify the drug. Though these names are usually easier to remember than chemical ones, they can still be difficult to pronounce. There is only one generic name for each drug, and many organizations worldwide use the generic name for identification, so students are encouraged to learn the generic names when learning about drugs. Though brand names are frequently used in the clinical setting, generic names are preferred for safety reasons. Generic names are also incorporated into the National Council Licensure Examination (NCLEX); therefore, it is helpful to learn the generic names of medications before sitting for a licensure exam.

A brand name (or trade name) is created by the drug company and marketed to providers and consumers. Usually, these names are much easier to pronounce and remember, so they are frequently used in the clinical setting. More than one drug company may produce the same drug. The generic name will be the same, but the brand name will differ. For example, ibuprofen is the generic name for a common nonsteroidal anti-inflammatory drug. Johnson & Johnson manufactures and sells ibuprofen under the brand name Motrin; however, Haleon produces and sells ibuprofen under the brand name Advil. Note that the drug’s brand name begins with a capital letter, but the generic name does not (see Figure 1.4).

Figure 1.4 The basic content of a drug label includes the drug brand name, drug company name, generic names, dosage, and form of the medication. (credit: modification of work “STRIBILD- elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate tablet, film coated” by National Library of Medicine/DAILYMED, Public Domain. Drug Company Logo All Rights Reserved.)

Prescription and Over-the-Counter Drugs

Prescription medications are drugs available to the client only by an order (commonly known as a prescription) from a health care provider. The health care provider must have the training and license to prescribe the drug. The prescription communicates the provider’s plan for the client and drug to the nurse or the pharmacist. Originally prescriptions were written using Latin terminology. R_X is an abbreviation of a 14th-century Latin term for recipe that meant “take.” Some of the Latin terms continue today, though the use of apothecary terms, such as grains, minims, and drams, is discouraged in practice for safety reasons. (See Drug Administration for more about the various systems of measurement.) Although prescription laws vary slightly from state to state, most require the following information (see Figure 1.5):

• Name, address, and phone number of the prescriber
• Date (and time, in some settings) the prescription was written
• Drug Enforcement Administration (DEA) number of the prescriber for controlled substances
• Client identification (name and date of birth)
• Client address
• Drug name and dosage strength with the number of dosage units to be prescribed
• Number of refills
• Prescriber’s signature

Figure 1.5 This sample prescription shows the required elements. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

Over-the-counter (OTC) drugs are available without a prescription to the public. They usually are safer than prescription products and are available for self-medication for various ailments. As long as the consumer follows the directions on the label, OTC drugs are usually safe and effective if used for a short time (FDA, 2018b). Some prescribers believe that allowing consumers to buy OTC drugs to treat minor illnesses permits individuals with more serious problems to be seen by the health care provider. However, it is also possible that by taking an OTC drug, the symptoms of a serious disease might be hidden or treatment delayed.

There are over 80 classes of OTC drugs, including pain and fever reducers, laxatives, antidiarrheals, and cold, cough, and allergy medications. Occasionally drugs are originally developed and sold only under prescriptive authority; however, after a period of time and with many clients using the drug, it is determined that it is safe for nonprescription use as an OTC. All OTC drugs are regulated and evaluated under the supervision of the FDA.

Over-the-counter drugs may still carry risks to the client. They are safe only if taken as recommended on the drug label. At times, consumers may inadvertently take more than the prescribed dose of an OTC due to taking more than one drug with the same product in it. The prescription medication Norco, for example, contains hydrocodone and acetaminophen. If taken with Tylenol (which also contains acetaminophen), the client may ingest more than the recommended dose of acetaminophen. The use of OTC drugs can be harmful in clients with some chronic diseases, such as diabetes, and those with liver or kidney problems. For example, acetaminophen is only safe when taken within the prescribed dose of fewer than 4 grams (4000 milligrams) per day—less should be taken if the client is older, malnourished, or has liver problems.

Many clients do not consider OTC drugs as medication and will not always report the use of these drugs. When taking a drug history, listing all dietary supplements and OTC drugs is crucial to prevent interactions.

Even though the cost of OTC medications is usually lower than those of prescription drugs, the cost of the OTC drugs is often incurred directly by the client. Insurance companies do not usually cover the cost of OTC medications.

This section would not be complete without a mention of complementary and alternative medicine (CAM). Medications are often used to treat clients in the Western world; however, other approaches are used outside the conventional treatment seen in Western medicine. Several of these were first developed in the Far East. Alternative medicine refers to using a treatment instead of mainstream conventional medicine, whereas complementary therapy refers to using both alternative medicine and conventional medicine together. These treatments may include massage, acupuncture, acupressure, mind–body interventions, or dietary supplements such as herbs or vitamins. One common use of CAM is in the treatment of cancer. Many drugs used to treat cancer have side effects of severe nausea and extreme fatigue. CAM may help clients cope with these symptoms through the use of acupuncture or the use of ginger or peppermint. Herbal therapy is also quite popular, but various herbals can interact with mainstream medications such as digitalis and blood thinners. St. John’s wort is an herbal supplement that interacts with drugs in the class of selective serotonin reuptake inhibitors and has the potential to cause a potentially fatal condition known as serotonin syndrome. Obtaining a list of herbals and supplements is vital when assessing a client’s medications. Herbals and supplements are not subject to FDA approval, and the supporting evidence for the use of these substances is low to nonexistent.

Drug Standards

The FDA is the government agency responsible for the regulation of the development, production, and sale of drugs. The FDA was given much closer control over the production of drugs after the drug thalidomide was prescribed to pregnant clients for the treatment of morning sickness and for sedation in the 1950s and 1960s. This drug was found to be highly teratogenic to fetuses and caused many fetal malformations, especially limb defects. The Kefauver-Harris Amendments in 1962 required drug manufacturers to establish the efficacy of drugs and gave the FDA more control over the testing of drugs before they were placed on the market.

The United States Pharmacopeia National Formulary (USP-NF) has a rich history, dating back to the inaugural publication of the United States Pharmacopeia in 1820. In 1888, the National Formulary (NF) joined its ranks. Then, in 1975, these two entities merged to form the formidable USP-NF. This institution operates as an independent, nonprofit organization dedicated to establishing vital standards for compounding medications, biologics, drug development, and manufacturing, both within the United States and globally. It produces the only official book of drug standards in the United States annually, and drugs referenced in this book have met very high standards for quality, strength or potency, and purity (U.S. Pharmacopeia, n.d.). The USP-NF is a nongovernment organization and is not associated with the FDA; however, the standards that the USP-NF puts forth are enforced by the FDA as the official standards for the production and quality control of drugs and dietary supplements in the United States. Complementary medications and supplements are not required to meet these same standards, though some do, and they carry a USP seal guaranteeing safe manufacturing and quality. The Canadian Food and Drugs Act also recognizes the USP-NF as a reliable authority of drug standards in Canada for health care providers.

There are many reliable sources of drug information for health care providers, including the American Society of Health System Pharmacists’ AHFS Drug Information book and Drug Facts and Comparisons. Many online resources are available to nurses, such as Medscape, Skyscape, DailyMed, and UpToDate. Applications can be downloaded to personal electronic devices or devices in the clinical setting (though not all are free). Often hospitals/health care systems and clinics have institutional access to these resources. It is helpful for the nurse to be able to access a wide variety of resources. A useful and free app for herbal supplements is About Herbs, which is produced by Memorial Sloan Kettering Cancer Institute. It is particularly helpful in the discussion of the mechanisms of action, herb–drug interactions, and adverse effects.

Drug Approval Process

The Center for Drug Evaluation and Research (CDER) is a branch of the FDA that evaluates new drugs before they can be sold in the United States. It provides health care providers and consumers with the information needed to use drugs appropriately. One of the tasks of CDER is to ensure that both brand-name and generic drugs work as they should (FDA, 2022b). Before any drug is sold in the United States, it must be tested. Once a chemical that may have therapeutic effects is isolated, it will undergo scientific tests and clinical trials to prove its efficacy and safety. Drugs must pass through several stages of development before receiving approval from the FDA to be marketed to consumers. Table 1.2 briefly describes the process of obtaining FDA approval for a new drug.

Some estimate the cost of developing just one new drug as ranging from less than $1 billion to over $2 billion (Wouters et al., 2020). The development of new drugs requires 10–15 years before the testing and drug studies are complete. Thousands of compounds are tested yearly, but only a few make it to clinical trials. Once a drug enters clinical trials, only a few are approved. CDER does not perform the clinical trials—this is up to the drug company; however, CDER reviews the pharmaceutical company’s data and the proposed drug labeling. At the heart of the approval process is establishing the health benefits of the drug and its safety profile. Does the benefit of the drug outweigh its risk?

There also are limitations to testing new drugs. Historically, there has been limited testing of drugs in the populations of females (particularly those of childbearing age), children (anyone under the age of 18 years old), and people of color (POC). This has recently changed, but before 2000, minimal testing was performed on females. No clinical trials were allowed for females of childbearing age, even if they were not pregnant and were taking effective birth control. This greatly limited knowledge about how females would respond to many drugs. This also means that there is limited data about drug safety during pregnancy.

Children were also excluded from clinical trials in the past, though some exceptions have been made more recently. According to the FDA (2016), only about 20% of drugs are approved for pediatric use. For that reason, physicians have had to prescribe drugs “off-label” for children. The problem is that well-controlled clinical trials for pediatric dosing have not been established for many drugs, meaning there is no safety data for most drugs. The reasons for this lack of data are somewhat surprising. Some believe that pharmaceutical companies saw little profit in medications for children. Finding adequate numbers of children for robust testing could be more of a challenge than with adults, especially in trials where blood would need to be drawn.

There are also ethical reasons to exclude children from trials, especially because children are unable to give consent. According to the FDA (2016, para. 7), “Parents are involved in the decision to enroll children in a study, and children ages 7 or older can ‘assent’ or ‘dissent,’ meaning they can agree or disagree to participate in a study.” For more information about children’s assent and parental permission, review this article by the National Cancer Institute. More testing has been conducted in the last decade, and the information coming out of those studies has shown much more accurate methods for dosing and prescribing. The FDA web page on drug research and children has more information.

Even as late as 2019, only 15%–19% of participants in U.S. clinical drug trials were Black. When broken down further, only 3% of participants in clinical trials for cardiovascular disease were Black males (6% were Black females), and less than 5% of oncology trial participants were Black males (2% were Black females) (Whyte, 2022). When specific populations are under-represented in a clinical trial, the efficacy and safety are unknown for that particular subset. The efficacy and safety of some drugs may differ for various ethnicities and genetic backgrounds (Clark et al., 2019). Due to a variety of barriers, racial and ethnic minorities are often underrepresented in clinical trials (FDA, 2022a). When clinical trials test therapies only within a homogenous group, the findings are likely to be skewed. One of the problems with this is that minority groups may have less benefit from those therapies. Some of the barriers to increasing minority involvement in clinical trials include a lack of understanding of the value of the process; mistrust of research; lack of information, time, and resources; and a lack of knowledge about the existence of various trials (Clark et al., 2019). Many differences in health outcomes have been documented based on race and ethnicity, underscoring the importance of including a variety of racial and ethnic groups in clinical trials.

Canadian Drug Regulation

The United States’ and Canada’s drug laws have evolved in a similar manner. Any drug manufacturer must provide scientific evidence of the drug’s safety, efficacy, and quality to Health Canada before the sale of that product is authorized. The federal review process by Health Canada was empowered by the Food and Drugs Act of 1927 as well as additional regulations (in 1953, 1954, and 1979) intended to protect consumers from risks associated with the production and sale of drugs, cosmetics, food, and medical devices (Health Canada, n.d.). It regulates the manufacturing, packaging, labeling, storage, and sale of food and drugs in Canada. It also determines whether a drug is a prescription or nonprescription medication. Canada requires prescriptions for narcotics and strict guidelines for record-keeping for prescribing and dispensing those drugs. Drug use in Canada is regulated and enforced by many different agencies, including Health Canada, the Royal Canadian Mounted Police, and agencies within various provinces.

Although the schedule of drugs is different from that of the United States (see Drug Classifications and Prototypes for U.S. drug schedules), Canada has tried to align the schedules throughout each province so that the sale of medications is consistent throughout the country. The governing body for Canadian national drug schedules is the National Association of Pharmacy Regulatory Authorities (NAPRA), though each province does regulate how drugs are sold or dispensed. In Canada, drugs are assigned to one of four categories (Drug & Alcohol Testing Association of Canada [DATAC], 2017; National Association of Pharmacy Regulatory Authorities, 2023):

• Schedule I: All prescription drugs. These drugs must be provided to the consumer by a pharmacist through a controlled, regulated environment. Drugs in this category include heroin, cocaine, morphine, and methadone.
• Schedule II: Restricted-access nonprescription drugs. These drugs may require professional intervention from a pharmacist when sold to the consumer. Must be stored with no public access or chance for the public to choose or select the drug (in other words, “behind the counter”). Schedule II drugs include insulin, pseudoephedrine, and sublingual nitroglycerin.
• Schedule III: Available without a prescription and sold on store shelves under the supervision of a pharmacist. Examples in this category are ibuprofen or naproxen.
• Unscheduled: Can be sold without supervision from any retail outlet. Emergency contraception, such as norgestrel, is considered an unscheduled drug.

Drug Counterfeiting

The United States has one of the world’s safest drug supplies, partly due to the FDA and USP-NF. Unfortunately, counterfeit drugs threaten that safety. Counterfeit drugs are products that are illegally manufactured or mislabeled with regard to their identity or source so that they appear to be a genuine product. They are fake drugs and may harm the recipient's health. Illegal online sales expose consumers to potential counterfeit drugs. Counterfeit drugs are not the same thing as generic medications. As mentioned earlier in this chapter, a generic drug is manufactured with the intent that it is identical in the active chemical ingredients, safety, strength, quality, dosage form, and intended use as its brand name counterpart (FDA, 2021a). These are drugs approved by the FDA. Counterfeit drugs are not.

Consumers can protect themselves by buying medications from state-licensed pharmacies in the United States. If using an online pharmacy, the consumer should check for the online pharmacy’s license through the state Board of Pharmacy. If it is not listed, that pharmacy should not be used. Reputable online pharmacies should have a seal of approval from the Verified Internet Pharmacy Practice Site (VIPPS). An online pharmacy should always require a health care provider’s prescription and have a physical address and phone number in the United States. Another strategy for the consumer is to be alert to changes or variations in the packaging of medications—for example, the color or lettering might be different. Consumers should be alert to any unusual taste or side effects from the drug and report it immediately. Concerns about potential counterfeit drugs should be reported to the FDA through its MedWatch website or by calling 1-800-FDA-1088. The 2013 Drug Supply Chain Security Act was passed as an initiative to combat the production and use of counterfeit drugs. The FDA’s Office of Criminal Investigations investigates counterfeit drugs, their producers, and their sellers and attempts to bring them to justice.