Pharmacology Flashcards
Drug Classes to treat Stroke
anti-thrombotics
thrombolytics
“prolol” endings
beta-blockers
“sartan” ending
angiotensin II receptor blockers
“pril” ending
ACE inhibitors
“actone” ending
potassium sparking diuretics
Factors affecting drug absorption
food –> increases stomach pH
lipid solubility of drug
polarity of drug
route of administration
Pharmacodynamics Definition
how drug impacts the body
Pharmacokinetics Definition
how the body processes a drug
“ADME”
ADME Definition
Absorption
Distribution
Metabolism
Excretion
How drugs work
1) replace or act as substitute for missing chemicals (insulin)
2) increase or stimulate cellular activity (cocaine)
3) decrease or depress cellular activity (fentanyl)
4) interfere with cellular functioning (invading neoplasms)
Agonist
a drug that causes a reaction (usually activity typical of that cell)
Antagonist
a drug that inhibits a cellular an effect. blocks cellular receptors or normal activity
Competitive antagonist
competes for receptors on cell membrane. blocks chemicals from binding with that receptor site and causing a reaction
Non-competitive antagonist
can be functional or allosteric.
functional = prevents agonist from causing a reaction
allosteric = binds to a non-agonist site on cell to inhibit receptor activation
Selective Toxicity
ability of drug to only target systems of foreign cells
Critical concentration
amount of drug required to induce a therapeutic effect
Loading dose
larger than normal dose of drug to accelerate a therapeutic reaction
preloading dose
Absorption
time period between administration of drug and drug reaching the circulatory system
Parenteral
outside the GI tract
Types of drug administration
PO IV IM SC Inhaled Rectal Transdermal Mucous membranes
Fastest drug route
IV
Factors impacting PO drugs
food increases stomach acidity
fatty food causes stomach to empty more slowly, affecting distribution
Absorption processes
passive diffusion
active transport
filtration
Distribution
movement of drug from circulation to bodily tissues
Factors affecting distribution
lipid solubility –> water-soluble particles unable to cross plasma membrane
polarity
perfusion of target tissue
protein transport
Which drugs can cross the BBB
lipid-soluble drugs
most antibiotic drugs are not lipid-soluble
Metabolism
aka biotransformation
detoxifying enzymes inactivate drugs and make them more water-soluble for excretion
Liver enzymes
cytochrome P450 enzymes
First-pass effect
PO drugs pass through GI tract –> hepatic portal vein –> liver where they get metabolized. less active drug available before it reaches circulation
Stages of Metabolism
Phase 1: biotransformation (inactivate drug) occurs via oxidation, reduction, hydrolysis
Phase 2: conjugation (water-soluble)
Enzyme Induction
enzymatic activity increases during drug metabolism
mixing drugs can cause a decrease the therapeutic effect by increasing metabolism of a particular drug
Organ responsible for metabolism
liver
Organ responsible for excretion
kidney
Routes of excretion
urine saliva bile feces sweat respiration
Factors affecting excretion
GFR (normally 50-60)
kidney disease
urine acidity
Half-life
time it takes for a drug to decrease by half of its peak amount
Accumulation
drugs can build up in the body. can be toxic if drug doses are not spaced out properly
(think of half-life)
Types of drug interactions
absorption site –> prevents absorption
distribution –> compete for protein transport
decreased metabolism –> toxicity
excretion –> accumulation & toxicity
site of action –> reduced therapeutic effect
Areas of drug interactions
absorption site –> prevents absorption
distribution –> compete for protein transport
decreased metabolism –> toxicity
excretion –> accumulation & toxicity
site of action –> reduced therapeutic effect
Prodrugs
drugs that are inactive upon administration and activated by liver metabolism
Types of drug interactions
synergistic (drugs amplify effect)
antagonistic (drug blocks/inhibits effect of another)
potentiation (drug that has no effect, amplifies another)
First Order Kinetics
drug elimination is proportional to concentration of drug in blood plasma
Zero Order Kinetics
drug elimination is independent of plasma concentration –> constant rate of excretion
higher risk for toxicity
