Pharmacology Stuff Flashcards
What’s the difference between pharmacodynamics (PD) and pharmacokinetics (PK)
Pharmacodynamics (PD) - What the drug does to the body (Beta Blocker slows HR etc..)
Pharmacokinetics (PK) - What the body does to the drug (absorption, distribution, metabolism, excretion)
What is efficacy?
A measure of maximum effect of a drug, regardless of the dose to achieve it
What is potency?
A measure of how much drug is required to achieve a specific effect, relative to the amount of another drug required to achieve same effect
What are the 4 main things associated with pharmacokinetics?
Absorption
Distribution
Metabolism
Excretion
What can affect absorption?
Solubility and dissolution of dosage
pH of stomach/intestines (immunosuppressants are weakly acidic and better absorbed in acidic environment, Stomach)
What is bioavailability?
The proportion of administered drug that reaches the systemic circulation
What is the bioavailability of intravenous and oral administration of drugs?
Intravenous = 100%
Oral
What is the first pass effect?
Drug is metabolized in the liver before it reaches systemic circulation
What factors can affect distribution?
- Blood flow to tissues
- Volume of distribution (lipid solubility)
- Protein Binding (if drug can’t find protein to bind to it becomes free drug)
- Blood Brain Barrier (lipid soluble drugs can pass through barrier)
What major organ is involved in metabolism?
Liver
What organ is mostly responsible for excretion?
Kidney (biggest)
- Lungs
- Skin
- Breasts
- Liver
What’s Steady State?
Same amount of drug delivered into the systemic circulation equals the amount that is eliminated
What is ED50?
Average effective dose for 50% of population
What is LD50?
Average Lethal dose for 50% of population
What is Therapeutic Index?
LD50/ED50
