Pharmacological principles Flashcards
What are the 3 Pharmacological Principles
Pharmaceutical phase
- break down and dissolution of pill/capsule
Pharmacokinetics
- what the body does to the drug
Pharmacodynamics
- what the drug does to the body
- The mechanism of drug actions in living tissues
Drug nomenclature
Chemical name
- drug’s chemical composition and molecular structure
Generic name(nonproprietary name) -given by Health Canada under the Food and Drugs Act and Food and Drug Regulations
Trade name(proprietary name) -drug has a registered trademark; use of the name restricted by the drug’s patent owner
the 4 phases of Pharmacokinetics
–Absorption
–Distribution
–Metabolism
–Excretion
Factors That Affect Absorption
- Administration route of the drug
- Food or fluids administered with the drug
- Dosage formulation
- Status of the absorptive surface
how does routes of adminstration affect absorption
- affects rate and extent of absorption
What are the routes
Enteral (passing the intestine)
–> GI tract – oral, sublingual, rectal
Parenteral (places other than the intestine)
–>IV, IM, subcutaneous
Topical (applied on or in at a particular place in the body)
–>skin, nose, lungs, eyes, ears
mechanism of First-Pass Effect
**it goes via the LIVER before going into systemic circulation
drug given via the oral route may be metabolized by the liver before reaching the systemic circulation
portal vein drains this blood directly into the liver then the blood gets drained by the right and left hepatic veins directly to the IVC
1st pass routes?
hepatic artery
oral
portal vein
rectal (both 1st pass and non-1st pass)
what is Distribution
transport of a drug in the body by the bloodstream to its site of action
what r the area of rapid distribution
heart, liver, kidneys, brain
what r the area of slow distribution:
muscle, skin, fat
how does fat soluble drug interact with cell
- diffuse easily through ell membrane
- activated nucleus receptor-drug/hormon complex and alters cell gene expression
- new Rna, DNa are synthesized
- new protein alter cell activity
how does water soluble drug interact with cell
- drug bind to cell membrane receptor, activiating G protein and adenlyate cyclases
- adenlyate cyclases converst ATP to cAMP
- cAMP is the 2nd messenger, activating protein kinasese
- protein kinasess phorpharlytes protein
- these protein than causes physiological process
what is metabolism in relationship to a drug
transformation of a drug into an inactive metabolite, a more soluble compound, or a more potent metabolite
sites of metabolism
liver
kidneys
lungs
plasma
what is excretion
elimination of drugs from the body
sites of excretion
Kidneys
liver
Bowel
what is half life
time it takes for one half of the original amount of a drug in the body to be removed
A measure of the rate at which drugs are removed from the body
what are 3 ways to quantify drug response in the body
Onset
- time it takes for the drug to elicit a therapeutic response
Peak
- time it takes for a drug to reach its maximum therapeutic response
Duration
- drug concentration is sufficient to elicit a therapeutic response
how does drug produce therapeuatic effect
once at at site of action, it:
- modify the rate ( increase or decrease) the function of cells or tissue
what are 3 MOA of Pharmacodynamics
Receptor interaction
Enzyme interaction
Nonspecific interactions
describe agonists at cellular level
drug with complete attachment and elicit a response with receptor
describe antagonists at cellular level
Drugs that attach but do not elicit a response
describe partial agonists or agonist-antagonists. at cellular level
Drugs that attach, elicit a small response, and also block other responses
def of Toxicity
production of severe adverse effects
def of Lethal Dose (LD50):
dose that will produce lethal effects on half of the test population
def of Effective Dose (ED50):
dose that will produce therapeutic effects on half of the test population
def of Therapeutic Index
a measurement of drug safety
TI=LD50/ED50
closer the calculation is to 1, the more toxic the drug
def of Tolerance
decreasing response to repetitive drug doses
- additional drug is required to produce the same desired effect
def of dependence
physiological or psychological need for a drug
4 types of drug interaction
– Additive effect 1 + 1 = 2
– Synergistic effect 1 + 1 =3
– Antagonistic effect
–>effect of two chemicals is actually less than the sum of the effect
– Incompatibility
–>undesirable reaction that occurs between the drug
what does % solution mean
gram or mls of drugs / 100ml of solution
