Drug Types and Usage

Introduction

Individuals who work in the healthcare field need to have a understanding of drugs and their use in patients. This includes how drugs work in the body, how they interact with other drugs, and which patients would benefit from their use. There are many different aspects of prescribing drugs, including their common identifying names, generic uses, regulations, ethics, and abuse-prevention strategies. All of these elements comprise a basic understanding of drugs.

 

Understanding Drugs and Their Use

Healthcare professionals must have a complete and thorough working knowledge of drugs, including the following topics:

1. Drug actions on the body
2. Precautions and contraindications of drug use
3. Reasons that physicians order specific drugs
4. Categories of medications as related to therapeutic effects on body systems

By understanding how patients respond to medication, healthcare professionals can do the following:

1. Explain possible drug interactions with other medications or food
2. Educate patients to ensure compliance and understanding
3. Answer patients' questions about possible reactions
4. Explain undesired effects and interactions

 

A drug is any chemical used for therapeutic purposes such as treating an illness, relieving a symptom, or conducting diagnostic testing. 

An ideal drug is a theoretical concept that a drug would have all good effects and qualities and no negative effects or qualities. An ideal drug would produce the same effect each time that the same dose is given to all patients. The ideal drug would be very easy to administer and convenient to use, and it would require dosing only once a day. The ideal drug would also be affordable so that all patients who need the medication would have access to it. And finally, an ideal drug would have a name that's easy to pronounce and remember.

However, at this time there are no ideal drugs. No drug is completely safe, because all drugs have some side effects. But there are safe drugs that can be taken in adequate doses over long periods of time with no harmful effects.

 

Types of Drug Interactions

A drug interaction is the combined effect of medications taken together. Drugs interact in various ways with other drugs, but they can also interact with nutrients. When multiple drugs are given together, some of the interactions are desirable, but others are undesirable. In fact, sometimes medications are ordered together to achieve a desired effect. Other drugs may counteract or augment a drug's effects or may interfere with the absorption, metabolism, and excretion of a drug. Interactions must be addressed so they don't cause the patient harm.

*The most common interactions are drug-drug interactions, but interactions can also take place between drugs and food.

 

Drug-Drug

When two or more drugs are prescribed together, three actions can occur:

• The drugs will have no effect on each other's action.
• One drug will increase the effect of the other, or both drugs will increase the effects of each other.
• One drug will decrease the effect of the other, or both drugs will decrease the effects of each other.

Most drugs don't have major interactions with other drugs or foods. However, when such an interaction occurs, it can be serious and even life-threatening. An example of a drug-drug interaction is Coumadin (warfarin) and St. John's wort. The St. John's wort can decrease the blood-thinning effects of the Coumadin.

Nutrient-Drug

Nutrient-drug interactions aren't all that well understood. In fact, they're still being studied. They can cause toxic effects or they can cause failure of therapy, depending on the drug-nutrient combination. Food in the stomach can significantly change the absorption of drugs. Some medications must be taken on an empty stomach, resulting in a more rapid absorption. Other medications are taken with food to maximize the absorption rate and decrease stomach irritation.

Consider this example: Green leafy vegetables, broccoli, Brussels sprouts, and cabbage contain vitamin K, which inactivates Coumadin. A patient who is to take Coumadin should be instructed to maintain the same dietary intake of these vegetables and not to vary their intake greatly. The dosage of Coumadin for each patient is based on that patient's bloodwork. If the patient's diet is stable with the amount of these types of vegetables, then the Coumadin will be dosed correctly. If the patient decides to eat several big, green, leafy salads filled with vitamin K–rich vegetables for a few days, then the result will be a decrease in the Coumadin's effectiveness.

Disease-Drug

Some drugs used to treat one disease can cause an exacerbation in or interfere with another disease or disorder that a patient may have at the same time. These disease-drug interactions tend to be be more common in older adults and patients with multiple chronic diseases.

An example is over-the-counter (OTC) cold preparations that contain ingredients known to be contraindicated for glaucoma and high blood pressure. Patients should always check with their physicians before taking any over-the-counter preparations. 

 

Drug Nomenclature

Drug nomenclature refers to all of the names by which a drug can be identified. All drugs have a chemical name, a generic name, a brand name, and possibly an OTC name.

The chemical name is usually a very long name of the chemical composition of the drug. It can be found in the package insert. It isn't often used in the dispensing process, but it's important to the FDA and the offices that register the patent on the drug. It's also important to chemists and other scientists working in the field of pharmaceuticals. 

For safety reasons, the proper way to express the name of a medication in the pharmacy and medical literature is by the generic name, also called the nonproprietary and approved name. This name is the official medical name assigned by the producer. It's found in the United States Pharmacopeia/National Formulary (USP-NF), a book of public standards related to pharmacology.

 

The brand name, also known as a trade or proprietary name, is given to a drug by the manufacturer, which means that the manufacturer owns the drug. The brand name is the one patients are more apt to recognize. These names have a registered trademark and are sold through a specific pharmaceutical manufacturer, which is generally the sole source of the product. Lipitor, Nexium, and Glucophage are examples of brand names.

Fortunately, in the United States, the National Drug Code (NDC) is indispensable in helping to identify each individual drug, regardless of which name is being used to describe the drug.

The following example should clarify your understanding of the distinction among these three names. It provides the three names for the common drug known as Tylenol.

Chemical Name          N-acetyl-p-aminophenol

Generic Name            Acetaminophen     

Brand Name               Tylenol

 

Generic Drugs

Generic drugs are made with the same ingredients and same dosage as brand-name drugs; however, they're not protected by a trademark. The generic drug is considered to be equivalent to the brand-name drug, but it's sold under the generic, or nonproprietary, name of the medication. Here are some examples: 

Brand Name        Generic Name

Lipitor                   atorvastatin

Nexium                 esomeprazole

Glucophage         metformin

 

Generic drugs have their own names as well. Both brand-name and generic drugs are regulated by the FDA.

 

You may be wondering if generic drugs are as effective as brand-name drugs. Generic drugs are the same as brand-name in the following ways:

• Safety
• Strength
• Quality
• Dosage
• Function

Generic drugs use the same active ingredients as brand-name drugs, so they have the same benefits and risks. The Food and Drug Administration (FDA) requires generic drugs to be the same quality, strength, purity, and stability as brand-name drugs.

 

New drugs are continually being developed and tested. First, scientists develop a new drug, which is first known by its chemical name but is usually referred to by its generic name. Once the FDA approves the drug, the manufacturer markets the drug with a brand name. Usually, the brand name is shorter than the generic name—it's a name that consumers can remember.

A superscript "R" on the product label indicates that the drug has been registered by the U.S Patent and Trademark office, and a superscript "TM" indicates a trademark.

A pharmaceutical company holds the patent to a new brand-name drug for about 20 years after its discovery. During this time, research and tests are conducted to approve the drug for FDA sale. The company usually has 11 to 12 years of sole rights to sell the drug to the public. After this time has expired, other companies can make a generic version of the drug. The generic version goes through a series of studies and must have FDA approval before it's marketed.

 

Let's take an example of a drug that everyone knows fairly well. The chemical name of this drug is 2-(4-Isobutylphenyl) propanoic acid. The generic name for this drug is Ibuprofen. It's a pain reliever and inflammation reducer that's approved for use by adults and children.

The drug was first synthesized in the early 1960s in England and became available in the United States in 1974 as part of the class of drugs known as NSAIDS (nonsteroidal anti-inflammatory drugs).

This drug was originally marketed in the United States by Upjohn as a prescription-strength drug called Motrin. It was 10 years later that an over-the-counter strength was approved. 

Now we know this drug by many names: Motrin, Advil, and others. Most of the time, you can also find this drug simply under its generic name, ibuprofen, on store shelves. As you can see, the timeline for drugs' production, even after they're discovered, can be lengthy.

 

Drug Regulations and Ethics

The Food and Drug Administration (FDA) is the government agency that decides what drugs may be sold and under what legal restrictions. In reference to a drug, the term over-the-counter (OTC) is actually a legal term, indicating that the FDA has placed no restrictions on the drug. A legend drug, on the other hand, can be distributed only by prescription because it may cause harmful side effects if not used with caution. Finally, controlled substances are drugs that are dangerous and subject to abuse. Many controlled substances do have acceptable medical usages and thus are allowed—under very rigid rules.

The FDA sets legal standards for the strength, purity, and quality in the manufacture of medications. In manufacturing a drug, a pharmaceutical company must produce the exact formula as approved by the FDA, with each dose at the exact same strength. The drug must be clearly identified by color, form, shape, size, and label.

*All health professionals must use confidentiality in all areas of patient care, from the front office to the back office. Medical offices have policies and procedures in place to help protect patient confidentiality. 

 

The approved indications and treatment for conditions are found in the package insert for the medication. However, some medications have off-label uses—that is, a medication can be prescribed to treat a condition that hasn't been studied by the manufacturer for FDA approval. The off-label use of drugs is becoming more frequent as physicians use medications and report their unexpected effects after the initial FDA approval has already occurred. An example of an off-label use is tricyclics used to treat chronic-pain syndrome.

 

The FDA enforces laws pertaining to the manufacture, packaging, and dispensing of prescription drugs and cosmetics. The Drug Enforcement Administration (DEA), on the other hand, regulates the manufacture and sale of dangerous drugs, such as narcotics. These substances became regulated by the DEA with passage of the Controlled Substances Act in 1970. The DEA categorizes controlled substances under five schedules, based on the potential for abuse and the medical usefulness of the drug. These schedules include the regulations for how the drug may be prescribed and stored.

                                                                                             Controlled Substances 

Schedule: Schedule 1: Uses: Drugs, substances, or chemicals with no currently accepted medical use and a high potential for abuse. Examples: Heroin, LSD, marijuana, ecstasy, methaqualone, and peyote

Schedule: Schedule 2: Uses: Schedule 2 drugs, substances, or chemicals are defined as drugs with a high potential for abuse, with use potentially leading to severe psychological or physical dependence. These drugs are also considered dangerous. Examples: Vicodin, cocaine, methamphetamine, methadone, hydromorphone (Dilaudid), meperidine (Demerol), oxycodone (OxyContin), fentanyl, Dexedrine, Adderall, and Ritalin

Schedule: Schedule 3: Uses: Schedule 3 drugs, substances, or chemicals are defined as drugs with a moderate to low potential for physical and psychological dependence. The abuse potential of Schedule 3 drugs is less than Schedule 1 and Schedule 2 drugs but more than Schedule 4. Examples: Tylenol with codeine, ketamine, anabolic steroids, and testosterone

Schedule: Schedule 4: Uses: Schedule 4 drugs, substances, or chemicals are defined as drugs with a low potential for abuse and low risk of dependence. Examples: Xanax, Soma, Darvon, Darvocet, Valium, Ativan, Talwin, Ambien, Tramadol

Schedule: Schedule 5: Uses: Schedule 5 drugs, substances, or chemicals are defined as drugs with lower potential for abuse than Schedule 4 and consist of preparations containing limited quantities of certain narcotics. Schedule 5 drugs are generally used for antidiarrheal, antitussive, and analgesic purposes. Examples: Cough preparations with less than 200 milligrams of codeine per 100 milliliters (Robitussin AC), Lomotil, Motofen, Lyrica, Parepectolin 

 

Because the DEA strictly enforces the regulations for controlled substances, the physician's office must keep precise and accurate records for Schedule 2 medications. If schedule 2 medications are stocked and administered in a physician's office, then there must be complete documentation kept from the time that the medication arrives in the facility until the medication is administered.

Physicians and other licensed health professionals who prescribe, dispense, or administer controlled substances must have a current state license to practice, be registered with the DEA, and have a DEA number assigned to them. Some states also require a state controlled substance license. Physicians must renew their DEA registration every three years for their DEA registration to remain valid.

 

 

Preventing Drug Abuse

Drug abuse is a national and international problem. Those working in the healthcare field must be aware of the problem and understand the responsibility to patients and society by being observant for signs and symptoms of drug abuse.

Prescription pads that physicians use for ordering need to be protected at all times. They should be kept in a locked drawer or cabinet when not being used. Prescription pads should not be left in the examination rooms. Many offices today primarily enter prescriptions electronically, thereby decreasing the risk of drug abuse occurring from prescription pad theft. Signs and symptoms of drug abuse can include:

1. Change in behavior, erratic behavior, or a lack of focus
2. Frequently changing healthcare providers, doctor shopping, or doctor hopping (not receiving care from one primary physician)
3. Physical health issues including lack of energy or motivation, drowsiness
4. Sudden change in work or school performance, neglected appearance, or lack of interest in grooming

 

Key Points

• A drug is any chemical used for therapeutic purposes such as treating illness, relieving a symptom, or conducting diagnostic testing.
• A drug interaction is the combined effect of medications taken together—how they interact with other drugs or nutrients.
• Drug nomenclature refers to all of the names by which a drug can be identified. The chemical name is the name of the chemical composition of the drug.
• The generic (nonproprietary; approved) name is the official medical name assigned by the producer and found in the USP-NF. 
• Generic drugs are made with the same ingredients and same dosage as brand name drugs but aren't protected by a trademark.
• The Food and Drug Administration (FDA) is the government agency that decides what drugs may be sold and under what legal restrictions. The FDA sets legal standards for the strength, purity, and quality in the manufacture of medications.
• The Drug Enforcement Administration (DEA) regulates the manufacture and sale of dangerous drugs, such as narcotics.
• The DEA regulates controlled substances; they're categorized under five schedules based on the potential for abuse and the medical usefulness of the drug.
• Medical professionals must be alert for signs and symptoms that indicate potential drug abuse.
• All health professionals must use confidentiality in all areas of patient care.
• Prescription pad theft is one of the most common ways people abuse drugs; use of an electronic system for prescriptions will decrease the issue of theft.