PHARMACOLOGY part 1

Absorption

Process by which a drug enters the circulatory system (blood).

Intravenous (IV) & Intra-Arterial

Administration/Dosage routs that do not require absorption.

Absorption, Distribution, Metabolism, & Elimination... The Pharmacokinetic Process

ADME

Addiction

Dependence characterized by a perceived need to take a drug to attain the psychological & physical effects of mood altering substances.

Affinity

Natural attraction - the strength by which a particular chemical messenger binds to its receptor site on a cell

Agonist

Drug that mimics the action of a neurotransmitter when it binds to a particular receptor site - i.e. & triggers the cell's response in a manner similar to the action of the body's own chemical messenger.

Allergen

Substance of a usually harmless nature that produces an abnormal hypersensitive reaction.

Allergic Response

A hypersensitive reaction to any usually harmless substance that does not normally cause a reaction.

Anaphylactic Reaction

Severe allergic response resulting in immediate life-threatening respiratory distress, usually followed by vascular collapse & shock accompanied w/ hives.

Angioedema

Abnormal accumulation of fluid in tissue.

Antagonist

Drug that neutralizes or counteracts the effects of a neurotransmitter or another drug when it binds to a particular receptor site.

Antigen

Foreign substance that is recognized by the immune system & induces the immune system to produce antibodies to defend against the foreign substance.

Bioavailability

Degree to which a drug or other substance becomes available to the target tissue after administration.

Blood-Brain Barrier

Fortified area that prevents many substances from entering the cerebro-spinal fluid from the blood. This area is formed by glial cells that envelope capillaries in the fcentral nervous system. This creates a shield that blocks many water-soluble compounds, but is permeable to lipid-soluble substances.

Ceiling Effect

Point @ which no clinical response occurs w/ increased dosage of a drug.

Clearance

Rate @ which a drug is eliminated from a specific volume of blood per unit of time.

Contraindication

Any disease, condition, or symptom for which a drug will not be beneficial & may be harmful.

Dependence

State in which a person's body has adapted physiologically & psychologically to a drug & cannot function w/o it.

Distribution

Process by which a drug moves from the blood into other body fluids & tissues & ultimately to its site(s) of action.

Dose

Quantity of a drug administered at one time.

Drug Abuse

Use of a drug for purposes other than those prescribed &/or in amounts that were not directed. This is often linked to addiction.

Drug Interaction

When a drug is affected in some way by another drug, foods, or other substances, such as when enzymes that metabolize the drug are induced or inhibited.

Drug Interaction Relationship: Addition

The combined effect of 2 drugs is equal to the sum of the effects of each drug taken alone.

Drug Interaction Relationship: Antagonism

The action of 1 drug negates the action of a 2nd drug.

Drug Interaction Relationship: Potentiation

1 drug increases or prolongs the action of another drug, & the total effect is greater than the sum of the effects of each drug used alone - drug potency is increased.

Drug Interaction Relationship: Synergism

The combined effect of 2 drugs is more intense or longer in duration than the sum of their individual effects. Drugs that work in combination like this are usually prescribed together.

Enzymes, Nucleic Acids, Receptors, & Transport Proteins

Types of specific body molecules that drugs can combine w/.

Duration Of Action

Length of time a drug gives the desired response/remains at the therapeutic level.

Elimination

Removal of a drug or the drugs metabolites from the body by excretion.

First-Order

Drugs for which the rate of elimination is concentration dependent (as opposed to \____ _ \_____).

First-Pass Effect

Extent to which a drug is metabolized by the liver before reaching full body circulation. This can substantially decrease bioavailability of certain drugs when administered orally, in which case administration by injection is required.

Half-Life

Time necessary for the body to eliminate half of the drug in the body @ any 1 time (written as T 1/2).

Homeostasis

Maintenance of stability in the internal environment of the body.

Induction

Process by which a drug increases the concentration of certain enzymes that affect the pharmacologic response to other drugs.

Inhibition

Process by which a drug blocks enzyme activity & impairs the metabolism of another drug.

Interaction

Change in the action of a drug caused by another drug, food, or another substance, such as alcohol or nicotine.

Lipid

Fatty molecule - An important constituent of cell membranes; they generally repel water.

Local Effect

Action of a drug that is confined to a specific part of the body.

Loading Dose

Amt of a drug that will bring the blood concentration rapidly to a therapeutic level.

Maintenance Dose

Amt of a drug administered at regular intervals to keep the blood concentration @ a therapeutic level. An important factor in determining this, is a drug's clearance rate.

Metabolic Pathway

Sequence of chemical steps that convert a drug tinto a metabolite.

Metabolism

Process by which drugs are chemically converted to other compounds.

Metabolite

Substance into which a drug is chemically converted in the body.

Peak

Top or upper limit of a drug's concentration in the blood.

Pharmacokinetic Modeling

Method of describing the process of absorption, distribution, metabolism, & elimination (ADME) of drug w/i the body mathematically.

Pharmacokinetics

Activity of a drug w/i the body over a period of time; includes absorption, distribution, metabolism, & elimination (ADME).

Prophylaxis

Effect of a drug in preventing infection or disease.

Pruritus

Itching Sensation.

Receptor

Protein molecule on the surface of or w/i a cell that recognizes & binds w/ specific molecules, thereby producing some effect w/i the cell.

Side Effect

Secondary response to a drug other than the primary therapeutic effect for which the drug was inteneded.

Solubility

Ability of a drug to dissolve in body fluids.

Specificity

Property of a cell receptor that enables it to bind only w/ a specific chemical messenger complementary to the structure of the receptor.

Systemic Effect

Action of a drug that has generalized - the all-inclusive effect of the drug on the body.

Therapeutic Effect

Desired action of a drug in the treatment of a particular disease , state, or symptom.

Therapeutic Level

Amount of a drug in the blood @ which beneficial effects occur. The amt. of time required to achieve this can be shortened by administering a loading dose.

Therapeutic Range

Optimum Dosage, providing the best chance for achieving the most effective & desired action... Dosing below this range has little effect, while dosing above this level (overdosing) can lead to toxicity & death.

Tolerance

Decrease in response to the effects of a drug as it continues to be administered.

Trough

Lowest level of a drug in the blood.

Urticaria

Hives, itching sensation.

Volume Of Distribution

mathematical relationship betw. the blood concentration attained & the amt. of drug administered.

Wheals

Slightly elevated, red areas on the surface of the body.

Zero-Order

Drugs for which the rate of elimination is not concentration dependent (as opposed to \_____ _ \_____).

Blinded investigational drug study

A research design in which the subjects are purposely unaware of whether the substance they are administered is the drug under study or the placebo. This method serves to eliminate bias on the part of research subjects in reporting their body's responses to investigational drugs.

Controlled substances

Any drugs listed on one of the "schedules" of the Controlled Substance Act (Also called scheduled drugs).

Double-blind investigational drug study

A research design in which both of the investigator(s) and the subjects are purposely unaware of whether the substance administered to a given subject is the drug under study or the placebo. This method eliminates bias on the part of both investigator and the subject.

Drug polymorphism

Variation in response to a drug because of a patient's age, gender, size, and/or body composition.

Expedited drug approval

Acceleration of the usual investigational new drug approval process by the U.S. Food and Drug Administration (FDA) and pharmaceutical companies, usually for drugs used to treat life-threatening diseases.

Informed consent

Written permission obtained from a patient consenting to
the performance of a specific procedure (e.g. receiving and investigational drug), after the patient has been given information regarding the procedure deemed necessary for the patient to make a sound or "informed" decision.

Investigational new drug (IND)

A drug not approved for marketing by the FDA but available for use in experiments to determine its safety and efficacy

Legend drugs

Another name for prescription drugs.

Narcotic

Applied to drugs that produced insensibility or stupor, especially the opioids (e.g., morphine, heroin). The term is currently used in clinical settings to refer to and medically administered controlled substance and in legal settings to refer to any illicit or "street" drug.

New drug application

The type of application that a drug manufacturer
submits to the FDA following successful completion of required human research studies

Orphan drugs

A special category of drugs that have been identified to help
or treat patients with rare diseases.

Over the counter drugs

Drugs available to consumers without a prescription.

Placebo

An inactive (inert) substance that is not a drug but is formulated to resemble a drug for research purposes.

Drug Legislation - FFDA

Required drug manufacturers to list on the drug product label the presence of dangerous and possibly addicting substances; recognized the U.S . Pharmacopeia and National Formulary
as printed references standards for drugs.

Drug Legislation - Sherley Amendment

Prohibited fraudulent claims for drug products

Drug Legislation - Harrison Narcotic act (1914)

Established the legal term narcotic and regulated the manufacturer and sale of habit forming drugs

Drug Legislation - FFDCA

Required drug manufacturers to provide data proving drug safety with FDA review; established the investigational new drug application process (prompted by sulfanilamide elixir tragedy)

Drug Legislation - Controlled Substance Act (1970)

Established "schedules" for controlled substances; promoted drug addiction education, research, and treatment.

Drug Legislation - Accelerated Drug Review Regulations (1991)

Enabled faster approval by the FDA of drugs to life threatening illnesses (prompted by the HIV/AIDS epidemic)

C-I Abuse Potential / Medical Use

High abuse potential and no medical use

C-II Abuse Potential / Medical Use

High potential for abuse / Accepted medical use

C-III Abuse Potential / Medical Use

++High abuse potential / Accepted

C-IV Abuse Potential / Medical Use

+++High abuse potential/ Accepted

C-V Abuse Potential / Medical Use

++++High abuse potential / Accepted

C-I Dependency Potential

Severe physical and psychological

C-II Dependency Potential

Severe physical and psychological

C-III Dependency Potential

Moderate to low physical or high psychological

C-IV Dependency Potential

Limited physical or psychological

C-V Dependency Potential

Limited physical or psychological

C-I Dispensing Restrictions

Only with approved protocol

C-II Dispensing Restrictions

- Written prescriptions only*
- No prescription refills
- Container must have warninglabel

C-III Dispensing Restrictions

- Written or oral prescription that expires in 6 months
- No more than 5 refills in 6-mo period
- Container must have warning label

C-IV Dispensing Restrictions

- Written or oral prescription that expires in 6 months - No more than 5 refills in 6-mo period
- Container must have warning label

C-V Dispensing Restrictions

- Written prescription or over the counter (varies with state law)

C-I Drug Examples

Heroin, LSD, marijuana, peyote, mescaline

C-II Drug Examples

Codeine, cocaine, morphine, oxycodone, methadone,
amphetamine, meperidine, secobarbital, methylphenidate

C-III Drug Examples

Codeine, hydrocodone, pentobarbital rectal suppositories, and dihydrocodeine combination products

C-IV Drug Examples

Phenobarbital, chloral hydrate, meprobamate, benzodiazepines (e.g., diazepam, temazepam, lorazepam), pentazocine