DRUG CLASSIFICATIONS

The definition of a drug is any chemical substance that has an effect on living tissue but is not used for food. Drugs are used on or administered to humans or animals as an aid in the diagnosis, treatment, or prevention of disease or other abnormal conditions, for the relief of pain or suffering, or to control or improve any physiological or pathological condition. A drug may be classified in various categories, depending upon different criteria. Examples are general, chemical, and therapeutic.

General\Drugs are grouped according to their source, whether animal, vegetable, or mineral in composition.

Chemical\Medications are grouped by their chemical characteristics. Examples are acids, bases, or salts.

Therapeutic (Pharmacological)\Drugs are classified according to their action on the body. A drug may have more than one action.

The drug classifications can be further divided into two groups: noncontrolled and controlled drugs.

Noncontrolled Drugs

Noncontrolled drugs are referred to as nonprescription, over the counter drugs (OTC), (i.e., aspirin, and mild analgesics). These drugs are effective for relieving most mild dental pain.

Controlled Drugs

All prescription drugs are to be treated with respect; certain groups considered to have a potential for abuse, such as narcotics, stimulants, and sedatives require special handling and security measures. Controlled substances are those drugs listed in the Controlled Substance Act of 1970 that is administered by the Drug Enforcement Administration (DEA) of the Justice Department. Controlled drugs are categorized into five schedules. MANMED, chapter 21, describes the schedules. Ethyl alcohol (used to fuel laboratory torches), although not included in any schedules of the Controlled Substances Act, must be received and accounted for, and dispensed in the same manner as schedule II substances described in MANMED, chapter 21.

DRUG NOMENCLATURE

The term drug nomenclature implies that there are several names that can be used to identify a drug. Normally drugs have three names: chemical, generic, and trade (brand).

Chemical name\Describes the chemical and molecular structure. The chemical name of a common dental local anesthetic called acetamide is 2-(diethylamino)-N-(2,6-dimethylphenyl)-monohydro chloride (C14H22N2O.HCL.H2O).

Generic name\Describes the common name of the drug. The above example has the generic name of lidocaine hydrochloride.

Trade name\This name is given by the manufacturer, and is also called the brand name.

DRUGS USED IN DENTISTRY

The drugs listed here are some of those commonly used in dentistry and are grouped according to pharmacological classes. Only a brief summary is possible here and the Dental Technician who desires more complete study of each drug should refer to reference books in the command library.

ACIDS

Acids are very caustic and present a sour taste. Extreme care must be taken when handling acidic substances. Follow all safety precautions on Material Safety Data Sheets (MSDS) for each product. A common acid used in dentistry is phosphoric acid, and comes in the forms of solutions or gels. It can be used in etching procedures with composite restorations, sealants, and orthodontic brackets.

EMOLLIENTS

Emollients are bland or fatty substances that may be applied to the skin to make it more pliable and soft, and can also serve as a lubricant in dental procedures.

Cocoa Butter (Theobroma Oil)

Cocoa butter is an excel lent emollient with a pleasant odor. It is ideal for the treatment of chapped or cracked lips, and can also be used as a lubricant in rubber dam procedures.

Petrolatum (Petroleum Jelly)

Petrolatum is highly occlusive and a good emollient. It can be used as a lubricant when handling sticky dental materials, and has several uses in the prosthetic laboratory.

DISINFECTANTS, ANTISEPTICS, AND GERMICIDES

These drugs and chemicals are primarily intended for the prevention of infections by destroying microorganisms or preventing their growth. The differences among them are based primarily on the degree of activity and how they are used. Complete details on their uses is covered in chapter 10, "Sterilization and Disinfection."

ANTIBIOTICS

Antibiotics are chemical compounds that stop the growth of or destroy different types of bacteria and other micro-organisms. They are used in dentistry to ^{treat oral infections.} They are also prescribed as a prophylactic (ward off disease) measure to prevent infective endocarditis (or IE) and in other medical conditions. Patients having history of infective endocarditis, rheumatic heart disease, artificial heart valves, and some heart murmurs are at high risk when involved in dental procedures that are likely to cause bleeding. They are prescribed a large dose of antibiotics before treatment and a smaller dose 6 hours after the initial dose. In all cases the dental officer will review the patient's health history and will prescribe an antibiotic if needed. Many types of antibiotics are available; listed are a few groups that are used.

Penicillin

Penicillin is one of the most important of the antibiotics. It is derived from a number of Penicillium molds commonly found on breads and fruits. It is one of the most effective and least toxic of the antimicrobial agents used in dentistry.

Cephalosporins

Cephalosporins are a group of antibiotics that are structurally and pharmacologically related to the penicillin. Because the cephalosporins are structurally similar to pencillians, some patients who are allergic to penicillin may be allergic to a cephalosporin drug. So, special caution is necessary when taking cephalosporins.

Tetracyclines

The tetracyclines, introduced in 1948, were the first truly broad-spectrum antibiotics. Administration to children and pregnant women is not indicated because it may produce discoloration of the teeth and slow bone marrow growth.

Erythromycin

Erythromycin has a bitter taste and is destroyed by gastric acids, and usually comes in the form of a coated tablet. Erythromycin is one of the drugs of choice when penicillin is contraindicated. Many patients cannot tolerate the nausea and stomach upset commonly associated with erythromycin, so the dentist may have to prescribe an alternate drug.