Pathopharmacology Exam 1

Pathopharmacology

Pathopharmacology

study of drugs, their actions, dosage, therapeutic uses, and adverse effects

drug

substance that alters biological activity in a person, mimics natural endogenous chemical

pharmacodynamics

drug-induced responses of physiologic and biochemical systems, what the drug does to the body and how it does it

pharmacokinetics

drug movement through the body and what the body does to the drug

pharmacotherapeutics

choice and drug application for disease prevention, treatment, or diagosistoxi

toxicology

study of the body’s response to drugs, harmful effects, mechanisms of actions, symptoms, treatment, identification

Pharmacy

preparation, compounding, dispensing, and keeping of therapeutic drugs

indications

approved uses or conditions for which drug has been proved to be effective

contraindications

circumstances in which a drug should not be administered

side effects

mild, undesirable effects of a drug, even at the recommended dose (ex. nausea, vomiting), secondary effect that is desirable or undesirable

adverse or toxic effects

dangerous effects, cause significant tissue damage, or are life-threatening (drop in BP, liver failure, etc)

Hypersensitivity

allergic reaction, may be mild or result in anaphylaxis

Idiosyncratic

unusual responses (ex. increased excitement after sedative)

Iatrogenic

negative effect associated with administration of drug (medication error, overdose)

Teratogenic

harmful effect on fetus, developmental defects, drug capable of causing birth defects

synergism

drug combination is greater than the sum of effects of individual drugs (1+1=3)

antagonism

combination of drugs decreases the effect of each drug

potentiation

1 drug enhances the effect of a 2nd drug (ex. epinephrine + local anesthetics → prolonged anesthetics)

loading dose

larger dose administered initially to raise blood levels to an effective levels

sublingual

under tongue

buccal

between cheek and gum

elixirs

sweetened, hydro-alcoholic- used in preparation of oral liquid medications

emulsions

mix of 2 liquids not mutually soluble

suspensions

liquid in which particles are mixed but not dissolved

transdermal

patch placed on the skin- drug absorbed for systemic effect

topical

medication spread or painted over an area of skin with a moist dressing or exposed to air

Instillations

liquid medications administered as drops, ointments, or sprays (ex. eyedrops, eardrops, nasal sprays)

Inhalations

medications that provide drugs to lower respiratory tract via inhalation

Suppositories

solid medical preparation (different shape for different location- rectum, vagina, urethra…)

Parenteral Medications

injection, outside of the GI tract

Intradermal

local effect, shallow injection into dermis (location chosen so reaction can be observed)

Subcutaneous

systemic effect, into tissue between dermis and muscle (location has adequate fat pad size)

Intramuscular

systemic effect, injection into muscle (location chosen based on large muscle size and minimal nerves)

Intravenous

systemic effect, immediate effect, into peripheral veins

prescription

signed legal document that must include patient’s identity information, prescriber’s info, data, name and amount of drug, dosage, route and directions for use of drug, permission for additional quantities

Drug absorption

drug movement from GI tract into bloodstream

Disintegration

breakdown of oral drug form into small particles

Dissolution

combining small drug particles

Diffusion

drugs move across cell membrane from high to low concentration

Facilitated diffusion

carrier protein moves drug from high to low concentration

Active transport

requires a carrier and energy to move drug against a concentration gradient

Pinocytosis

cell carries drug across membrane by engulfing drug particles

Enteric-coated (EC) drugs

resist disintegration in the gastric acid of the stomach, disintegration doesn’t occur until drug reaches alkaline environment of small intestine (delayed effect)

First pass effect

some drugs are metabolized to an inactive form and are excreted, reducing the amount of active drug available to cause pharmacologic effect (in liver)

bioavailability

percent of administered drug available for activity- affected by absorption and first pass effect

free drugs

drugs that are able to exit blood vessels and reach action site for pharmacologic effect

blood-brain barrier

protects brain from foreign substances

drug metabolism (biotransformation)

process of body chemically changing drug into a form to be excreted, chemical alteration of drug structure

Cytochrome P450

enzymes in liver that play role in metabolism

prodrug

compound metabolized into an active pharmacologic substance

half-life

time for drug to be reduced by half

steady state

plates drug level, same amount of drug being administered as excreted

direct penetration

drug goes directly through the cell membrane (must be lipid-soluble), most common

channels and pores

allows for small compounds, such as K and Na, to enter cell

transport system

protein that moves drugs through the cell membrane

Enteral

via the GI tract

polar molecules

no net charge, unevenly distributed

ions

molecules with a positive or negative net charge, unable to cross membranes

Distribution

movement of drugs throughout the body

movement of drugs at capillary beds

lipid-soluble- pass between the through cells

ionized or polar- cannot pass through cells, but can pass between

movement at blood brain barrier

ionized or polar molecules- pass only through a transport system

lipid-soluble- can pass through cell but not between because of tight junctions

placental drug movement

only lipid-soluble drugs can pass through

Excretion

removal of drugs from body

Glomerular filtration

moves drugs from blood to tubular urine; protein bound drugs remain in blood

passive tubular reabsorption

lipid-soluble drugs go back into blood, ions and polar compounds remain in urine

active tubular secretion

pumps for organic acids and bases from blood to urine

breast milk

a non renal route for drug excretion, lipid-soluble drugs pass readily, while polar, ionized, or protein bound drugs do not cross

bile

a non renal route for drug excretion, drugs are secreted into small intestines and excreted through feces

lungs

a non renal route for drug excretion, volatile anesthetics

Minimum effective concentration (MEC)

bare minimum amount of drugs for therapeutic effect

Toxic concentration

plasma level where toxic effects begin

Therapeutic range

range between MEC and toxic concentration

primary effect

desirable effect

secondary effect

effect that is desirable or undesirable

Dose-Response Relationship

body’s physiologic response to changes in drug concentration at the site of action

Potency

amount of drug needed to elicit a specific physiologic response to a drug

Maximal efficacy

point at which increasing a drug’s dosage no longer increases the desired therapeutic response

Therapeutic index

relationship between the therapeutic dose of a drug (ED50) and the toxic dose of a drug (TD50) (difference b/w these 2 points)

ED50

dose of a drug that produces a therapeutic response in 50% of the population

TD50

dose of a drug that produces a toxic response in 50% of the population

Therapeutic range

range of doses that produce a therapeutic response without causing significant adverse effect in patients

onset

time it takes for a drug to reach the MEC after administration

peak

when drug reaches highest concentration in the blood

duration of action

length of time the drug elicits a therapeutic effect

trough drug level

lowest plasma concentration of a drug- measures rate at which a drug is eliminated

cell-membrane embedded enzymes

type of receptor with LBD on the surface, drug is activated inside the cell

ligand-gated ion channels

type of receptor, ions flow in and out (Na, Ca)

G-protien coupled receptor system

type of receptor system in which the drug activates a receptor, receptor activates G protein, and G protein causes an effect

transcription factors

type of receptor in cell nucleus on the DNA, regulates protein synthesis

ligand-binding domain

site on the receptor at which drugs bind

agonist

activate receptors and produce desired response, drugs that produce the same response as the endogenous substance

partial agonists

elicit only moderate activity when binding to receptors, prevent receptor activation by other drugs, response is diminished compared with that elicited by an agonist

antagonist

molecules that produce their effects by preventing receptor activation by endogenous regulatory molecules and drugs

nonspecific drug

drugs that affect multiple receptor sites, but same type of receptor

nonselective

drugs that affect multiple different receptors

stimulation

enhances intrinsic activity

depression

decreases neural activity and bodily functions

irritation

noxious effect

replacement

replaces essential body compounds

cytotoxic action

kill invading parasites or cancers