DH127 Exam 1 Study Guide: Key Terms and Definitions in Medicine

Allergic reaction

not predictable, not dose-related

Generic vs. trade name

Generic name is always lowercase, trade name is always capitalized. EX: Ibuprofen is the generic name and Motrin is the trad name, acetaminophen is the generic name and Tylenol is the trade name.

Pharmacokinetics is the study of...

what the body does to the drug

Pharmacodynamics is the study of...

what the drug does to the body

Drugs can have ___ generic name

1

Drugs can have ___ trade/brand name

more than 1

After ____ years, the patent of the original drug expires

20

Describe when drugs are chemically equivalent

When 2 formulations of a drug meet the chemical & physical standards established by the regulatory agencies

Describe when drugs are biologically equivalent

If 2 formulations produces similar concentrations of the drug in the blood & tissues

Describe when drugs are therapeutically equivalent

If 2 formulations prove to have equal therapeutic effects in a clinical trial

The FDA grants approval for...

marketing of a drug in the US when it is determined safe & effective

FDA regulates...

labeling and advertising of prescription drugs

FTC (federal trade commission) regulates...

trade practices associated with drug marketing

FTC prohibits...

false advertising of food, nonprescription drugs, & cosmetics

DEA (drug enforcement administration) is the chief federal agency responsible for...

the scheduling of drugs that have potential for abuse, including opioids, stimulants, & sedatives

Drug development can take ____ years

10-15

Clinical testing of investigational new drug (IND) steps

Four phases

What are the phases of clinical testing?

Phase I

Phase II

Phase III

Phase IV

What occurs during phase I of clinical testing?

Phase I:

small & then increasing doses are administered to a limited number of health human volunteers, primarily to determine safety

What occurs during phase II of clinical testing?

Phase II:

Larger groups of humans are given the drug & any adverse reactions are reported to the FDA

What occurs during phase III of clinical testing?

Phase III:

More clinical evaluation takes place involving a large number of patients who have the condition for which the drug is indicated

What occurs during phase IV of clinical testing?

Phase IV:

This phase involves post-marketing surveillance

The toxicity of a drug that occurs in patients after it is released is recorded

What can happen during phase IV is a drug shows toxicity?

it can be removed from the market

What phase is dosage determined?

Phase III

What is the main purpose of Phase II?

to test effectiveness

What does Phase I determine?

determines the biologic effects, metabolism, & safe dose range in humans, & the toxic effects

Schedule drugs are also known as...

controlled substances

Schedule I drugs

- High Potential for abuse

- No prescriptions may be written for drugs

Schedule II drugs

A type of drug with medicinal uses that is highly addictive and only available with a written prescription

Schedule III drugs

- has potential for abuse, but to a lesser degree than schedules I + II

- may not be dispensed without a prescription

- may not be dispensed six months after prescription written

- may not be refilled more than 5 times

- may be prescribed orally or over phone

Schedule IV drugs

- low potential for abuse

- can be refilled up to five times after 6 months written or orally

- can be telephoned in

Schedule V drugs

- These drugs have less potential for abuse

- can be bought OTC in some states

Give an example of a drug with a black box warning

Acetaminophen - potential for severe liver damage & allergic reactions

The heading of a prescription includes:

- Name, address, & telephone number of the prescriber

- Patient's name, address, telephone, & age

- Date of prescription

The body of a prescription includes:

- Symbol Rx

- Name & dosage, size, or concentration (liquids) of the drug

- Amount to be dispensed

- Directions to the patient of drug, dose, form, & amount

The closing of a prescription includes:

- Prescribers signature

- DEA (drug enforcement number) if required

- Refill instructions

disp.

dispense

ac

before meals

bid

twice a day

Sig

means "write" — directions to the patient

h

hour

hs

at bedtime

PO

by mouth

prn

as needed

q

every

qid

four times a day

stat

immediately

tid

three times a day

Dose-Effect Curve

Determines the potency & efficacy of a drug's action

For the Dose-Effect curve, the x-axis (horizontal) is an...

increasing dose of the drug

For the Dose-Effect curve, the y-axis (vertical) is an..

increasing effect of the drug

For Dose-Effect curve, as the __________ is increased, the __________ increases

dose, effect

Log Dose-Effect Curve

A line graph of percent effect dose against percent minimum response

For Log Dose-Effect curve graph, as the dose is increased, the effect is ______ at first, then there is a small effect, & finally the effect quickly ___________

zero, increases

For Log Dose-Effect curve, once maximum response is reached, further increase in dose will...

NOT produce increase in drug response — may lead to toxic or adverse reactions

The potency of a drug is...

the amount of drug required to produce an effect

The more potent drug, the _____________ the dose to achieve effect

smaller

Efficacy is the maximum effect or response produced by a drug...

regardless of dose

What is therapeutic index (TI)?

Ratio of lethal dose (LD50) to effective dose (ED50)

The greater the TI the _________ the drug

safer

Examples of drugs with high TI:

- NSAIDs, aspirin, beta-blockers

Examples of drugs with low TI:

warfarin

lithium

digoxin

phenytoin

If the value of the TI is small (narrow), then toxicity is ______ likely

more

Drug receptors — Drugs that enhance cell function are called ___________

Adonists

Drug receptors — Drugs that inhibit cell function are called ________________

Antagonists

Types of Antagonists

competitive, noncompetitive, & physiologic

Competitive antagonists are...

drugs that have affinity for a receptor & produces no effect

Noncompetitive antagonists are...

drugs that bind to a receptor site that is different from the binding site for the agonist

Physiologic antagonist are...

drugs that have affinity for a different receptor site than the agonist & decrease the maximal response of the agonist by producing an opposite effect via different receptors

Key points to Pharmokinetics (ADME)

Absorption

Distribution

Metabolism

Excretion

Ideal drugs are...

non-ionized and highly lipid-soluble

What are the physiochemical properties of drugs that influence the passage of drugs across biologic membranes?

Lipid Solubility

Degree of Ionization

Molecular size and shape

Describe each aspect of ADME

Absorption: process by which drug molecules are transferred from the site of administration to the circulating blood; requires drug to pass through membranes

Distribution: the passage of drugs into target organs, non-target organs, plasma, interstitial fluid, brain, placenta, etc.

Metabolism: the body’s way of changing a drug so it can be more easily excreted by the kidneys

Excretion: the route of excretion

What are the different aspects of the metabolism stage of ADME?

drugs break down in different ways:

- Active to inactive

- Inactive to active

- Active to active

Describe Active to Inactive of drug metabolism

most common type of reaction in drug biotransformation

active compound is converted to an inactive compound

Describe Inactive to Active of drug metabolism

Inactive compound is transformed into an active compound

Describe Active to Active of drug metabolism

active compound is converted into a second active compound & is then converted into an inactive compound

Describe the First-pass effect

when the concentration of the drug is greatly reduced before it reaches systemic circulation. occurs in liver

Describe the half-life of a drug (t1/2)

Time it takes for the concentration of the drug in the blood to fall to half (50%) of its original value

It takes about ________ half-lives for a drug to be considered eliminated from the body

4-5

Drugs with a short half-life (2-4 hours) need to be administered ______ frequently

more

Drugs with a long half-life (21-24 hours) need to be administered _______ frequently

less

Factors that alter drug effects

Size, age, gender, tolerance, pathologic state, time of administration, patient adherence, psychological factors, route of administration, environment

Why would pathologic state alter drug effect?

For instance, if a patient has hyperthyroidism, they will be extremely sensitive to the toxic effects of epinephrine because epinephrine causes release of thyroid hormones & causes vasoconstriction, which could increase heart rate even more of those with hyperthyroidism

Routes of administration are classified as:

enteral or parenteral

Enteral route of administration

oral, sublingual, rectal — placed in GI tract

Parenteral route of administration

-Bypasses the GI tract

-Types include:

> Intravascular (IV)

> Intramuscular (IM)

> Intradermal

> Subcutaneous

> Inhalation

> Sublingual

Toxic reaction

an exaggeration of the known and desired effects of a drug; predictable

Side effect

Predictable, dose-related, acts on non-target organs

Describe when a drug interferes with natural defense mechanisms

certain drugs, such as adrenocorticosteroids, can reduce the body's ability to fight infection. the drug interferes with the body's defenses causing patient to get infections more easily & have more trouble fighting them

Hypersensitivity reactions

Type I- Anaphylactic (immediate)

Type II- Cytotoxic

Type III- Immune complex

Type IV- Cell Mediated

Angie Cant Imagine Men

Which type of hypersensitivity reactions are most seen in dental?

Type I & IV

Describe the reaction involved in Type I hypersensitivity

IgE antibody induced by allergen and mediators released (i.e. histamine is released)

Describe the reaction involved in Type II hypersensitivity

IgG or IgM antibodies combine with antigens on cell surface & lead to lysis — cytotoxic

Describe the reaction involved in Type III hypersensitivity

antigen-antibody complexes attract PMNs & cause tissue damage; immune complex

Describe the reaction involved in Type IV hypersensitivity

T lymphocytes release lymphokines that induce inflammation and activate macrophage that in turn release various mediators; ex: poison ivy — delayed reaction

Toxicologic evaluation of drugs

Nervous system

autonomic nervous system (ANS) functions as an automatic modulating system for...

Heart rate

Blood pressure

GI motility

Salivary gland secretions

Bronchial smooth muscle

Afferent fibers

carry sensory signals from receptors to the CNS — "What's happening?"