Intro: Wk 1 Flashcards
pharmacology
-Study of how drugs interact with body to produce therapeutic effects
-Effect of drugs on living systems
-Complex science that requires knowledge of biochem, physio, orgo and molecular bio
drug + what are namings for the drug
-Anything used to treat, dx or prevent disease
What’s in a name? (Ex – Tylenol):
-Chemical name: N-acetyl-p-aminophenol
-Generic: acetaminophen
-Brand (commercial): Tylenol
-Abbreviation: APAP
-Classification of drugs:
-May be based on structure, mechanism of action or the effects it produces
Drug Control and Development
1906 – Pure Food and Drug Act (free for all- opiates in everything)
• 1938 – Food, Drug and Cosmetic Act (eyeliner- women losing eyesight, need for safety of pt.)
New drug Application (NDA) – must be submitted to FDA before drug can be marketed
1962 – Efficacy data required→was no safety data or evidence that things worked submitted w/ any commonly used medication + had few medications
clinical testing of drugs
-phase 1 – clinical pharmacology: establishes safety
-Phase II – clinical investigations: HUMANS*/animals, establishes efficacy and dose
-Phase III – clinical trials: checks adverse effects
-Phase IV – post marketing studies
PITP
drug measurements
Metric System: (ml, L, kg,g)
Apothecary System: (grains grams oz)
Avoirdupois System: (mass of pounds and oz)
1kg= _____lb
2.2lb
1tsp is how many ccs
1 tbsp is how many ccs
5ccs
15ccs
pharmacodynamics
*** What a DRUG does to the BODY – how they work
- Biochemical & physiological effects of drugs and mechanisms of action (MOA)
Bts song - Dynamics MOA -> D MOA
Dose-response curve
-ideal dose response curve: action increases as concentration increases -> S curve
Shows increasing probability of a certain drug effect as dose level rises
More drug= greater response
pharmacokinetics
What BODY does to DRUG
-How body absorbs, distributes, metabolizes, excretes
ADME
-IV is 100%
-95% of drugs are systemically distributed
Pharmacotherapeutics + Risk-benefit ratio
-Prevention and treatment of disease
-Risk-benefit ratio* -> how SAFE is a drug:
-Used to describe adverse effects of drug in relation to its beneficial
effects
-Acceptability of ratio depends on severity of disease being treated
examples of benefits vs adverse effects
Benefits:
-Reduce morbidity
-improve quality of life
- effectiveness of drug,
- ease of administration- (such as tablet form)
Adverse:
- Cost
- inconvenience of administration- (such as injection)
toxicology
Study of poisons (recognition, treatment, prevention)
Drugs:
- Adverse drug reactions (ADRs) or side effects (SEs) at therapeutic doses
- Adverse events can end up becoming medications: Viagra/rogaine
- Toxicity at higher doses
Chemicals: NOT used in therapy (household, industrial, environmental, drugs of abuse)
Teratology
“The study of monsters”
–How drugs taken during pregnancy can cause fetal morphology
Ex: retinols (Accutane - category x), thalidomide – you have no effect but your female child will have the effect
-category A, B, C, D, X (worst) -> some drugs can change category based on trimester
Category of Drugs and Pregnancy
A safest
X causes teratogen
A- D increases in harm/ unknown harm
A: No risk to fetus
B: Possible effect on fertility but no evidence of risk in first trimester or later trimesters
C: Adverse effects shown on animal testing, only give drugs if potential benefit justifies potential risk to fetus
D: Positive evidence of human fetal risk, use only in life threatening situations
X: Fetal abnormalities and fetal risk; contraindicated in women who are/may become pregnant
Therapeutic Index (TI)
TI: margin of safety
-Drugs with a high TI are “safe”
-Drugs with a low TI are “not safe” – usually require therapeutic blood level monitoring
ED: effective dose -> lowest dose with effect
Humans: TD1/ED1
- Minimum toxic dose/minimum therapeutic dose
In animals LD50/ED50 -> lethal dose / effective dose
drugs with low TI
Digoxin
lithium
AMG,
Vanco
Phenytoin
Carbamazipine
Warfarin
= Less safe -> usually require therapeutic monitoring!!!
How do drugs work?
-Drug goes to site of action (biologic molecule) = RECEPTOR
-Receptor may be: membrane, membrane protein, cytoplasmic or extracellular enzyme
-Drug binding site: proteins, glycoproteins or lipoproteins
-Specificity – receptor must be able to recognize a drug for it to work
-Lock & Key - drug-receptor complex
-Drug-receptor complex – produce a biochemical or physiological response
effects of drug binding
-Release of neurotransmitter
-Release of hormone
-Release endogenous chemicals
-Change electrical potential
-Changes membrane permeability
-Cause cascade effect
Partial agonist
has affinity but low efficacy
-butorphenol
duration of action
-one a day- long duration of action
-4 times a day- short duration of action -> low affinity to receptor
agonists
- Drug that combines with a receptor and activates that receptor, produces same response and causes release of chemical
- Has affinity (tendency for drug to bind) for a receptor and efficacy (ability to produce desired or intended result)
antagonist
-Drug that combines with a receptor used by an endogenous chemical and blocks or diminishes the response of the endogenous agent
-Drug that inhibits the release of an endogenous compound.
-Drug that intercepts the signal generated by an endogenous agent.
Competitive vs noncompetitive antagonist
-Competitive Antagonism – agonist and antagonist compete for the same
receptor site
-Non-competitive antagonism – agonist and antagonist bind at different sites on the same receptor
-low doses it works -> high doses it loses effects
-often pain pills
potency vs efficacy
-Potency: If the dose of drug A is less than drug B to achieve the same response –> Drug A is more
potent (1mg vs. 100mg)
-high dose drugs are not potent
-Efficacy: The magnitude of the maximum effect (predefined) -> relative to a person -> maximal effect in a person
Potency
Amount of drug needed for the same effect
Drugs with high specificity and affinity for binding site would you need less of the drug
If the dose of drug A is 1mg is less than drug B 100mg and they achieve the same response, which is more potent?
DRUG A is MORE potent
-Drug A more potent bc less of drug causes same effect
efficacy
The magnitude of the maximum effect
2 different drugs , Drug A 5mg Drug B 5mg
lower effect of drug A, lower efficacy
tolerance
-Reduced response to the same dose or increased dose needed for
the same response
Causes:
-Change in receptor sensitivity
-Change in pharmacokinetics of
drug
-Usually happens slowly, depends on the drug, some do and some
don’t.
-ex: Narcotics, Nitroglycerin
