PSYCHOPHARMACOLOGY UPDATED FINAL PAPER
QUESTIONS AND SOLUTIONS GUARANTEE A+
✔✔transdermal application - ✔✔slow absorption due to the skin (effective barrier
against diffusion)
patches use lipophilic substances that penetrate skin. controlled and sustained
✔✔liberation - ✔✔durg release into biological system from an administered form
✔✔excipients - ✔✔chemicals added to drugs to allow drugs to exist in different forms
✔✔formulations - ✔✔a specific form of a drug that changes liberation
control the rate of delivery only when the liberation rate is LESS than the absorption rate
✔✔bioequivalence - ✔✔if two drug formulations have equal bioavailability and rate of
adsorption the resulting plasma levels will be similar if liberation is also the same.
✔✔route of administration graph - ✔✔IV straight line fastest
IM second fastest
PO smallest curve
SC larger curve
IM-oil takes longest
✔✔advantages and disadvantages of selected routes of drug administration - ✔✔
✔✔Cell membranes - ✔✔phospholipid bilayer creates barrier to allow only aqueous
molecules that are lipophilic drugs or uncharged molecules to pass
✔✔passive diffusion - ✔✔down the concentration gradient
high to low
✔✔facilitated diffusion - ✔✔movement by transport protein down the concentration
gradient
✔✔carrier mediated active transport - ✔✔movement by a transport protein against the
concentration gradient
from low to high
requires ATP
✔✔lipid soluble drugs - ✔✔move across membranes via passive diffusion - movement
down concentration gradient
, must be hydrophobic otherwise it will not penetrate. if too hydrophobic it will stay in
membrane
✔✔salt forms of drugs - ✔✔move/keep drugs in more stable state
substitute the salt for hydrogen
increases solubility
causes dosing problems becasue salt is heavy
✔✔Ionization depends on two factors: - ✔✔acidity
drug ionization characteristics
✔✔acidity (pH) effect on drug - ✔✔the closer to neutral, the easier it is to be absorbed
✔✔drug ionization characteristics (pKa) - ✔✔represents the pH of solution in which 50%
of the drug is ionized and 50% is non-ionized.
-weak acids ionize in more alkaline environment
-weak acids ionize less in acidic environment
✔✔a highly charged drug in acidic and basic environments are_______ absorbed in the
GI tract and cannot be administered orally - ✔✔poorly
✔✔distribution - ✔✔circulation of drug to target sites within a biological system
influenced by extent of blood flow, diffusion of drug out of circulation to target sites and
selective barriers to diffusion
✔✔apparent volume (Vd) - ✔✔describes distribution characteristics of a drug to the
body
-influenced by lipid solubility
-defined as amount of durg that leaves circulation and enters organs
-defined in liters
✔✔Vd = 3 - ✔✔will distribute to 3L of body fluid, it will stay in the blood
✔✔Vd = 42L - ✔✔total body volume is 42 to this will distribute to whole body
✔✔The higher the Vd - ✔✔the more likely to go to brain quickly
✔✔first phase of distribution - ✔✔due to preferential blood flow to target organ (brain)
-brain receives preferential blood flow
-concentration reduced everytime it passes through liver because it is degraded
✔✔second phase of distribution - ✔✔due to drug solubility in other body tissues
QUESTIONS AND SOLUTIONS GUARANTEE A+
✔✔transdermal application - ✔✔slow absorption due to the skin (effective barrier
against diffusion)
patches use lipophilic substances that penetrate skin. controlled and sustained
✔✔liberation - ✔✔durg release into biological system from an administered form
✔✔excipients - ✔✔chemicals added to drugs to allow drugs to exist in different forms
✔✔formulations - ✔✔a specific form of a drug that changes liberation
control the rate of delivery only when the liberation rate is LESS than the absorption rate
✔✔bioequivalence - ✔✔if two drug formulations have equal bioavailability and rate of
adsorption the resulting plasma levels will be similar if liberation is also the same.
✔✔route of administration graph - ✔✔IV straight line fastest
IM second fastest
PO smallest curve
SC larger curve
IM-oil takes longest
✔✔advantages and disadvantages of selected routes of drug administration - ✔✔
✔✔Cell membranes - ✔✔phospholipid bilayer creates barrier to allow only aqueous
molecules that are lipophilic drugs or uncharged molecules to pass
✔✔passive diffusion - ✔✔down the concentration gradient
high to low
✔✔facilitated diffusion - ✔✔movement by transport protein down the concentration
gradient
✔✔carrier mediated active transport - ✔✔movement by a transport protein against the
concentration gradient
from low to high
requires ATP
✔✔lipid soluble drugs - ✔✔move across membranes via passive diffusion - movement
down concentration gradient
, must be hydrophobic otherwise it will not penetrate. if too hydrophobic it will stay in
membrane
✔✔salt forms of drugs - ✔✔move/keep drugs in more stable state
substitute the salt for hydrogen
increases solubility
causes dosing problems becasue salt is heavy
✔✔Ionization depends on two factors: - ✔✔acidity
drug ionization characteristics
✔✔acidity (pH) effect on drug - ✔✔the closer to neutral, the easier it is to be absorbed
✔✔drug ionization characteristics (pKa) - ✔✔represents the pH of solution in which 50%
of the drug is ionized and 50% is non-ionized.
-weak acids ionize in more alkaline environment
-weak acids ionize less in acidic environment
✔✔a highly charged drug in acidic and basic environments are_______ absorbed in the
GI tract and cannot be administered orally - ✔✔poorly
✔✔distribution - ✔✔circulation of drug to target sites within a biological system
influenced by extent of blood flow, diffusion of drug out of circulation to target sites and
selective barriers to diffusion
✔✔apparent volume (Vd) - ✔✔describes distribution characteristics of a drug to the
body
-influenced by lipid solubility
-defined as amount of durg that leaves circulation and enters organs
-defined in liters
✔✔Vd = 3 - ✔✔will distribute to 3L of body fluid, it will stay in the blood
✔✔Vd = 42L - ✔✔total body volume is 42 to this will distribute to whole body
✔✔The higher the Vd - ✔✔the more likely to go to brain quickly
✔✔first phase of distribution - ✔✔due to preferential blood flow to target organ (brain)
-brain receives preferential blood flow
-concentration reduced everytime it passes through liver because it is degraded
✔✔second phase of distribution - ✔✔due to drug solubility in other body tissues
