Pharmacology Flashcards
Pharmacokinetics
what the body does tp the drug
pharmacodynamics
what the drug does to the body
F=1 for IV drugs
100% drugs enter systemic circulation
F<1 for oral admin (incomplete bioavailability)
incomplete absorption and losss in faeces
first pass metabolism in gut lumen
F=0.1
dosage needs to be 10 times higher than Ivdose
Volume of distribution
theoretical volume necessary to contain the total amount of an administered drug at same conc observed in blood plasma
phase 1 metabolism
preconjugation,non synthetic reactions
=molecule is suitable for phase 2
phase 2 metabolism
conjugation/synthetic reactions;addition of endogenous substance
inc water solubility and inactivates drug
more polar and more readily excreted by the kidneys and liver
first order elimination kinetics
elimination and drug conc is not uniform.
most physiological and metabolic processes are first order
zero-order elimination
fixed rate
metabolism removes fixed amount of drug/given time
drug conc drops linearly
overdoses=longer to clear
clearance
clearance=rate of elimination from the body / drug conc in the plasma
loading dose
Css x Vd
therapeutic index
dose resulting in toxicity/dose giving therapeutic response
high ti=low risk toxicity
4 receptor families in pharmacodynamics
- ligand gated ion channels
- G-protein coupled receptors
- Kinase-linked receptors
- Nuclear Receptors
types of agonist
full agonists: 100% effect of the endogenous agent
Partial agonists: <100% effect
Super agonists >100% endogenous effect
Inverse agonists:reduce basal receptor activity
