Absorption

movement of a drug from site of

administration into the blood stream

Active Transport

movement of a drug through a gradient of concentratioin in the direciton opposite to normal diffusion requiring expenditure of energy.

Additive Effects

combined effect of drugs that, when used in combination, produce an effect that is greater than the sum of their separately measured individual effects.

Adverse Reaction

any harmful, unintended effect of a medication, diagnostic test, or therapeutic intervention.

Affinity

strength of the attraction between

a drug and it's receptor.

High affinity has high relative potency.

Agonist

a molecules that activate receptors.

Agranulocytosis

complication of drug therapy that results in decreased granulocytes and lesions of the throat,

mucous membranes, GI tract, skin.

Albumin

major plasma protein, responsible for plasma

 colloidal osmotic pressure and serving as a

transport protein for some drugs

Hypoalbuminemia

abnormally low levels of albumin in the blood.

(May occur in celiac disease, tropical sprue, malnutrition, and some other forms of liver or kidney impairment.)

allergy (drug)

hypersensitivity to pharmacologic agent; range

from rash to anaphylaxis, depending on dose

and allergen sensitivity of individual. 

(PCN, ASA, antibiotics, iodine, are common).

Anaphylaxis

life threatening, rapidly progressing allergic reaction.

Antagonist

prevent receptor activation by endogenous

molecules and other drugs. 

area under the curve

subtherapeutic dose reflected in measurement of a therapeutic agent that is present in the circulation in a determined time period - often 24 hours.

Auto Induction

??

Bioavailabiliity

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

Bioequivalent

a drug that has the same effect as another drug, usually one neraly identical in chemical formulation but possibly requiring different amount to see same effect.

Biotransformation

aka metabolism and biodegradation

chemical alteration of a drug, within the body,

as by the action of enzymes

blood brain barrier

physiological mechanism that alters permeability of brain capillaires so that some drugs are prevented from entering brain tissue, while others are allowed to enter freely.

Carcinogenic

ability to cause cancer

Clearance

elimination of a drug from the body; drugs and metabolites are excreted primarily via the kidneys in the urine; rate of clearance determines size and frequency of dosage.

Competitive Agonist

??

Dangerous Drug

All drugs can be dangerous.

Dependence (Physical)

resulting from chronic use of drug that has produced tolerance and where withdrawal results from abrupt discontinuation or dosage reduction. 

Dependence: Psychological

addiction; physiological craving is a craving whereas psychological dependence is a "need" because it causes enjoyable mental effects. 

Desensitizatioin

 Continuous exposure of cells to agonists can result in receptor desensitization (aka refractoriness or down-regulation).  Continuous exposure to antagonists can result in hypersensitivity (aka supersensitivity)

Distribution

pattern of movement of drug molecules by various tissues after it enters the circulatory system.

Dose Response Curve

relationship between some effect, for example lowering of BP - and the amount of durg.

Drug Interaction

one drug affects the ability of another drug when administered together; action can be synergistic or antagonistic or a new effect can be produced that neither produces on its own.

Can be drug-drug, drug-food, drug-plant.

Drug Onset

the point at which the drug takes effect; the duration of time it takes for a drug's effects to come to prominence upon administration.

Drug Duration

how long the drug effects lasts or is effective.

Drug Peak-Trough Cycle 

certain drugs require measurement of peaks and trough levels to establish effectiveness.  Peak is drawn after drug is administered as it distributes rapidly and reaches its peak in therapeutic range.

Trough is lowest drug level needed to reach therapeutic range.  If trough is > than normal, pt is at risk for adverse effects. 

dose-response relationship

effect produced that varies with concentration present at site of action and usually approaches max value beyond w hich further increase in concentration is no more effective.  A useful measure is ED50 which is the dose producing a response that is 50% of max obtainable.

down-regulation

process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external variable.  In increase of a cellular component is called upregulation.

ED50 (Effective dose 50%)

dose of a drug required to produce a defined therapeutic response in 50% of population

Efficacy

extent to which a drug is effectively therapeutic; a measure of drug to treat whatever

condition it is indicated for.

Elimination

combination of metabolism and excretion to get drugs out of the body.

Enteral

any route of drug administration that involves

absorption in the gastrointestinal system.

Enteric Coated

barrier applied to oral medication to control location of absorption in digestive system.

Enterohepatic Recirculation

cycling of drugs and metabolites after excretion in the biliary system, which are reabsorbed in the intestine.

Facilitated Diffusion

movement of drug across a cell membrane via a specialized transport system embedded in the cell membrane; does not require energy but does not move drug against a concentration gradient.

First-Pass Effect

the metabolism of oral meds by GI and hepatic enzymes, resulting in a significant reduction of the amount of unmetabolized drug reaching the systemic circulation.

Half-Life

time required for half the quantity of a drug to be metabolized or eliminated by normal biological processes.  Also called biological half-life.

Hemolysis

the breakdown of RBC; hemoglobin is freed up.

Hypersensitivity Reactions

an inappropriate and excessive response of the immune system to a sensitizing antigen called an allergen.

Iatrogenic

resulting from the activity of physicians.

idosyncratic reaction

aka ADR

Induction / Inducer

An enzyme inducer is a type of drug that increases the metabolic activity of an enzyme either by binding to the enzyme and activating it, or by increasing the expression of the gene coding for the enzyme;

Intrinsic Activity (Efficacy)

 refers to ability of a drug to activate receptors.

Ionized

positively charged, to separate into ions; to dissociate atoms or molecules into electrically

charged atoms or radicals

LD50

lethal dose required to kills half the members of a tested population after a specified test duration. 

LD50 figures are used as a general indicator or a substance's acute toxicity.

legend drug

any drug that requires a rx.

lipid solubility

the ability to pass through a lipid membrane;

ability to dissolve in fat.

Lipophilic

attraction to, or solubility in lipids

Margin of Safety

amount of space between therapeutic dose

and lethal dose

Maximal Efficacy

greatest effect a drug can produce

Metabolism

process by which body breaks down and converts medication into active chemical substances

Minimum Toxic Concentration

minimum concentration at which a drug

produces toxic effect

Minimum Effective Concentration

the minimum plasma concentration required for a

drug to be therapeutic

Mutagenic

inducing genetic mutation

Nephrotoxic

toxic to kidneys

Noncompetitive Agonist or Antagonist

Don't compete for receptor sites??

Nonionized

not converted into ions

off-label

to use for a therapeutic purpose other than what has been approved by the FDA

OTC

Over-the-Counter

Ototoxic

Toxic to the ear; deleterious effect upon the eigth nerve or on the organs of hearing and balance

Partial Agonist

not as effective as agonist; affinity for and stimulates physicologic activity at cell receptors normally stimulated by naturally occurring substances 

Passive Diffusion

passage of molecules across a semipermeable membrane WITHOUT the expenditure of energy

pH

measure of acidity or alkalinity of a solution;

scale commonly used is 0-14.

Pharmacodynamics

concerned with action and breakdown

of drugs in the body

Pharmacogenomics

technology that analyses how genetic makeup effects an individual's response to drugs

Pharmacokinetics

action of drugs in the body including absorption, distribution, metabolism, and excretion

Pharmacology

study of drugs, total science of drugs,

including use in therapeutics

Pharmacotherapeutics

use of drugs in medicine to treat disease

Placebo

inactive substance administered to some patients in clincial trials to determine effectiveness of another drug administered to a second group of patients.

Plasma Concentration

measure of how much of a compound

is present in a sample of plasma

Polypharmacy

lacks univeral definition; typically means more than one drug and typically refers to use in the elderly. 

Sometimes referred to as excessive

or unnecessary prescriptions.

Potency

amount of drug required to produce given % of maximal effect, irrespective of the size of maximal effect.

Potentiation

synergistic action in which the effect of two drugs given simultaneously is greater than the sum of

the effects of each drug given separaetly.

Prophylactic Therapy

treatment used to prevent disease or problem.  also called preventive treatment

Protein-Binding

drug's efficiency may be affected by the degree to which it binds to proteins within blood plasma.  The less bound, the more the drug can traverse

cell membranes or diffuse

Relative Potency

comparison of required quantities of two drugs - an already standard (reference) drug and a newer test drug - to produce the same defined effect. 

Selectivity

ability to bind to or have an affinity for a SPECIFIC receptor; depicts a molecule with greater affinity for one receptor or any process for that matter over another

Serum Sickness

reaction that is similar to an allergy to a drug; immune system is involved.

Side Effect

undesirable secondary effect of a drug

Spectrum of Activity

range that a drug can reach and still be effective

i.e. antibiotics

Subtherapeutic

below dosage level needed to treat disease

Synergism

interaction of elements that when combined produce a total effect that is greater thant he sum of the individual elements or contricutions, etc...

Tachyphylaxis

very rapid development of tolerance or

immunity to effects of a drug

Teratogenic

known to cause birth defects in an embryo or fetus

Therapeutic Effect

consequence of medical treatment of any kind the results of which, are judged to be desirable and beneficial.

Therapeutic Index

aka Therapeutic Ratio

compariosn of a therapeutic agent that causes therapeutic effect to the amount that causes death.

LD divided by minimum effective dose for 50% of pop (ED50).  Higher TI is preferable to a lower one as a pt would have to take a much higher dose to reach lethal threshold than the dose taken to elicit the

therapeutic effect. 

Tolerance

a pt's reaction to a drug decreases so that a larger dose is required to achieve the same effect.

Toxicology

Concerned with the study of adverse effects of chemicals on living organisms; study of symptoms, mechanisms, treatments and detection of poisoning.

Volume of Distribution

term used to quantify distribution of med between plasma and rest of body after oral dosing.  

VD = total amt of drug in body divided by

drug blood plasma concentration

Water Soluble

dissolvable in water

Prodrug

 initially administered to the body in an inactive (or less than fully active) form, and then becomes

converted to its active form through the normal metabolic processes of the body