1- Flashcards
(29 cards)
What is Pharmacokinetics ?
A principle of pharmacology : what the body does to the drug.
What is Pharmacodynamic ?
A principle of pharmacology : what the drug does to the body.
Why is the mode of administration important in drug ?
It allows to act on multiple parameters of the drug : The rapidity of the drug to reach the target organ, the lenght of the effect, the organ to target , what is the final effect, local or systemic effect …
On what depends the effectiveness of the absorbsion ?
1) molecular size & shape
2) degree of ionization (mor effective when not ionized)
3) lipid solubility of ionized & non-ionized forms
4) its binding to serum and tissue proteins
5) for oral administration, drug must be soluble and stable in stomach fluid + surface area of the region of absurption (gastro/intestine).
what determines the bioavailability of a drug ?
+Absorption, distribution, metabolism and elimination determine the availability of a drug.
What is a xenobiotic ?
A chemical substance found within an organism that is not naturally produced or expected to be present in the living organism
What is the fate of the drug ?
Administration, absorption, distribution, binding, action and elimination
When the drug is oral, what is the best form for it to be absorbed ?
Nonionized and lipophilic form
Is the absorption the same in the estomac and in the intestine ?
No, bigger surface in interstie and ph 3 to 6 in intestine
Which one is the largest organ for absurption ?
Skin
What is the “drug pass effect” ?
Before the drug is available for use (ex: orally, GI tract, hepatic portal vein, liver)
How to measure bioavailability ?
Concentration of bioavailable medicine in the body % of dose in time. Calculating area under the curve to compare
What is Cmax ?
Maximum concentration of the drug in the body
What is the bioequilence of a drug ?
when two drug are equivalent: way of administration, same active ingredient, same strenght and concentration
What is the distribution ?
When the drug distribute into te intersticial and intracellular fluid.
What determines rates and amount of distribution ?
cardiac output, lipid slubility, transmembr ph gradient, half life, blood flow, plasma protein, capillarity permeability.
What are capillaries ?
single layer of cells packed tightly together,t hey habe small pores, connect arteriole and venules, enable exchange of water, frug oxyge,beteen blood and surrounding tissues
What is the use of the blood brain barrier ?
only lipid soluble drugs can nter the brain, prevennt inflitration of patogens thkx to endothelial cells.
What is the metabolism of a drug ?
the breakdown of the drug
Where metabolism happen ?
Liver
what are the main phases of metabolism ?
new ore modified fctal group. parent frug become more polar metabolites (can involve hydrolisis of reduction of the drug, oxidation).
II phase ; cibjugation with an endogenous compoind ? attachment of an ionised grop to the dreg. Convert metabolits more polar and more readily exreted metabolites by renal or biliary eliination. SOme dug are toxic, detoxification at phase 2
what is oxidation ?
catalised bu cytovhtor P450 enzymes and results in the loss of electrons from the drugs
What are cytochrome families ?
microsomal superfamily , isoenzymes that transfer electrons and catalize oxidation
who are microsomal superfamily , isoenzymes that transfer electrons and catalize oxidation
cytochrome
