Chapter 30

Principles of Pharmacology

Pharmacology

• The science or branch of medicine that conducts research and development in the use and effects of drugs

Drug

• A substance used in the prevention, diagnosis, or treatment of a disease.

• All drugs must be recognized and defined by the US Food, Drug and Cosmetic Act before they can be marketed to the public in the US

A drug is identified by three names

• Chemical name: which is the chemical formula of a drug

• Generic name: which may be used by any company; acetaminophen is an example of a generic name

• Brand name, or trade name: which is controlled by business firm as a registered trademark; such as Tylenol is brand name for acetaminophen

Dispensing

• Patent medicines: drugs that can be obtained without a prescription; also known as over-the-counter drugs

• Ethical drugs: Prescription drugs (from a physician or dentist), supplied to patients only by a pharmacist.

Prescriptions

• A written order by a physician or dentist for preparation and administration of a medicine

• Persons legally authorized to prescribe medications are issued a Federal Drug Enforcement Agency (DEA) identification number.

• Dental assistants cannot prescribe medications

Terminology of Prescriptions

• Superscription: patient name, address, the date and symbol Rx

• Inscription: name and quantity of the drug

• Subscription: directions for mixing the medication

• Signature: instructions for the patient on how to take the medication, when and how much

Telephone Guidelines

• Narcotics cannot be ordered without a written prescription

• It is illegal for a Dental assistant to “call in” a prescription

• Notify the dentist if the Pharmacist calls the office

• Never attempt to evaluate a patient’s reaction to a drug.

Mosby’s Drug Consult

• Annual source of information supplied by drug companies

• It is a bound text, as well as a electronic source

Drugs

• Local-acting drug– Affects only the specific area of the body to

which it is applied, such as a topical ointment

• Systemic drug– Taken internally– Can affect the whole body by way of

circulatory system

Administration

• Four stages– Absorption

• Absorbed from site of entry—speed varies, slowest is orally

– Distribution• Enters bloodstream, attaches to proteins within blood, and

circulates throughout the body

– Metabolism• Compound is released, and drug becomes metabolized and

is then excreted through liver or kidneys

– Excretion• Drug leaves the body by way of kidneys, liver, breast milk or

sweat

Routes

• Oral—tablets, liquid

• Topical—apply on surface of mucosa

• Transdermal –patch that continuously releases medication

• Inhalation—breathing in substance

• Sublingual—medication placed under the tongue

Controlled Substances Act

• Drugs that are covered under the Federal Comprehensive Drug Abuse Prevention and Control Act are divided into five schedules

Schedules

• Schedule I– No current accepted medical use/high potential for abuse

• Schedule II– High potential for abuse, some medical usefulness

• Schedule III– Less abuse potential than Schedule I and II, and has accepted

medical usefulnes

• Schedule IV– Low abuse potential and have accepted medical usefulness

• Schedule V– Lowest abuse potential and accepted medical usefulness/no

prescription needed

Chapter 37

• Anesthesia and Pain Control

Topical Anesthesia

• Provides numbing effect in an area where in injection is to take place– Ointments, liquids, sprays or patches

Local Anesthesia

• Most frequently used form of pain control in dentistry

• Obtained by injecting an anesthetic solution near a nerve where treatment is to take place

• Each local anesthetic cartridge contains– Local anesthetic drug– Sodium choloride– Distilled water

Uses of Vasoconstrictors

• Slows down the intake of an anesthetic agent and increases the duration of action

• Prolongs the effect of the anesthetic agent by decreasing the blood flow in immediate area of the injection

• Decreases bleeding in the injected area

Contraindications to Vasoconstrictors

• May cause strain on the heart• Not recommended for patients with a

history of:– Angina– Chest pain (heart related)– Recent myocardial infarction– Coronary artery bypass surgery– Untreated or severe hypertension– Congestive heart failure

Duration of Anesthetics

• Know the duration (in minutes) of each of the following– Short-acting local anesthetic– Intermediate-acting local anesthetic– Long-acting local anesthetic

Injection Techniques

• Infiltration Anesthesia– Usually used for Maxillary arch– Also used for secondary injection to block

gingival tissues surrounding mandibular teeth

• Block Anesthesia– Usually used for mandibular arch– Block nerves for the quadrant

Syringe

• Know the parts of the syringe and their functions

Cartridges/Disposable Needle

• Know the color-coding system• Know the parts of the cartridge• Know the parts of the needle • Know the size of the needle for dentistry• Lumen—the hollow center of the needle-how the

anesthetic flows through needle– The larger the gauge number—thinner the needle– The smaller the gauge number—thicker the needle

Complications and Precautions

• Know in detail– Injection into a blood vessel– Infected areas– Toxic reactions– Systemic reactions– Temporary numbness– paresthesia

Inhalation sedation

• Know the chemical make-up

• Advantages of Nitrous Oxide Use

• Contraindications of Nitrous Oxide Use

• Equipment

• Intravenous sedation– Understand the uses of IV sedation

• General Anesthesia– Know definition– Know in detail the four stages of anesthesia

• Happy Testing