Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
68 Cards in this Set
- Front
- Back
What is pharmacokinetics?
|
What the BODY does to the DRUG
|
|
What is pharmacodynamics?
|
What the DRUG does to the BODY
|
|
What are the 4 pharmacokinetic processes of a drug?
|
A bsorption
D istribution M etabolism E xcretion |
|
What type of diffusion requires energy?
|
Active transport
|
|
What type of diffusion is limited to movement down a concentration gradient (i.e. from higher to lower)
|
Passive transport
|
|
What factors affect drug distribution?
|
1. lipid solubility
2. degree of ionization 3. molecular size |
|
What type of drug penetrates the cell membrane better, ionized or unionized?
|
Unionized (nonionized)
|
|
What does the pKa of a drug mean?
|
50% is unionized & 50% unionized in a specific pH
|
|
Give examples of weak base drugs
|
1. Ketamine
2. Opioids 3. Benzodiazepines 4. Etomidate |
|
Give an example of a weak acid
|
1. barbituates
|
|
If a weak acid drug is placed in an acidic pH, what is the dominant form (ionized/unionized)?
|
Unionized
(Remember: Acid + Acid = more unionized) |
|
If a weak base drug is placed in an acidic pH, what is dominant form (ionized/unionized)?
|
Ionized
(Remember: Base + Acid = ionized) |
|
If a weak acid drug is placed in an alkalotic pH, what is dominant form (ionized/unionized)?
|
Ionized
(Remember: Base + Acid = ionized) |
|
If a weak base drug is placed in an alkalotic pH, what is dominant form (ionized/unionized)?
|
Unionized
(Remember: Base + Base = more unionized) |
|
Does the pKa determine if a drug is a weak base or a weak acid?
|
No; pKa only tells the degree of ionization/unionization from the pH of the solvent (depending if acid/base drug in acid/base solution)
|
|
Lidocaine is injected IV into a pregnant woman, it crosses the placenta and is unable to come back out. This is an example of:
|
Ion Trapping
|
|
What factors affect absorption of a drug?
|
1. Lipid Solubility
2. Concentration 3. Blood flow 4. Surface area for absorption 5. Route of administration |
|
Which routes are considered to result in 100% bioavailablity?
|
1. IV (parenterally)
2. inhalation |
|
What affects bioavailability in an orally administered medication?
|
"First pass effect" (liver metabolism)
|
|
What factors affect drug distribution?
|
1. Lipid solubility
2. Blood flow 3. Tissue binding 4. Protein binding |
|
What protein prefers to bind to weak acid drugs?
|
Albumin
|
|
What proteins prefer to bind to weak base drugs?
|
1. alpha-acid glycoprotein (AAG)
2. beta-globulin |
|
If drugs are protein bound, what CANNOT occur to the drug?
|
1. Diffusion
2. Metabolization 3. Excretion 4. Cause effects |
|
Binding of drug molecules to proteins is usually _____________
|
competitive
|
|
What is the Blood-Brain barrier?
|
cerebral capillaries held tightly together by astrocytes that limits passage of molecules
|
|
What is the formula for volume of distribution (Vd)?
|
flow (Q)
Vd = --------------- plasma conc.(Cp) |
|
Does volume of distribution refer to any anatomical or physiological compartment?
|
No; only infers how quickly the uptake of the drug occurs outside of the central compartment
|
|
What 2 processes comprise elimination?
|
1. metabolism (biotransformation)
2. excretion |
|
What is a metabolite?
|
The result of metabolism of the parent drug
|
|
What is a prodrug?
|
An inactive form that becomes active after metabolization in the body
|
|
What are basic Phase I reactions in metabolism?
|
1. Oxidation
2. Reduction 3. Hydrolysis |
|
What is a basic Phase II reaction in metabolism?
|
1. Conjugation (synthetic rxn)
|
|
Besides the liver, where else does biotransformation take place?
|
1. Plasma
2. Kidneys 3. Lungs 4. GI tract |
|
The liver uses what enzyme pathway?
|
CYP-450 (Cytochrome P-450)
|
|
What drugs induce (speed up) the CYP-450 pathway?
|
1. Alchohol
2. Phenobarbital (anti-sz) 3. Phenytoin (anti-sz) 4. Rifampin (TB drug) 5. Carbamazepine (anti-sz) |
|
What is stereochemistry?
|
Study of 3-D isomers
|
|
What is a chiral center?
|
The center of a 3-D molecule that is assymetric when the mirror image is superimposed
|
|
What is a racemic mixture?
|
A 50/50 mix of drug enantiomers
|
|
What is the drug receptor response formula?
|
D + R <---> DRC <---> TR
D = drug R = receptor C = complement T = tissue |
|
What is efficacy?
|
The amount of cellular response in relation to receptor binding
|
|
True or False:
Receptors on cells are static |
False; they are dynamic (constantly changing)
|
|
What condition prompts cell receptor up-regulation?
|
An UNDER stimulation results in a quantitative INCREASE of surface receptors
|
|
What condition prompts cell receptor down-regulation
|
An OVER stimulation results in a quantitative REDUCTION in surface receptors
|
|
What is affinity?
|
The degree of attraction between two things (e.g. drug & receptor)
|
|
What determines affinity and efficacy?
|
The closer a drug's molecular structure is to the receptor shape, the higher the affinity and the higher the efficacy
|
|
What are the 2 different types of receptors?
|
1. Receptors that open gates/channels
2. Receptors that prompts internal enzymatic activity (2nd messengers) |
|
Name an example of a 2nd messenger that functions outside of the cell membrane
|
ACh-esterase projects outward into the synaptic cleft to metabolize ACh
|
|
Which portion of the G-protein sub-unit relays the message: alpha, beta, or gamma?
|
Alpha
|
|
Name examples of second messengers
|
1. cAMP
2. cGMP 3. Calcium 4. Inositol triphosphate (IP3) 5. Calcium-calmodulin |
|
If a synthetic drug can bind to the same site as an endogenous substance, the drug is called a(n) ______________
|
Agonist I
|
|
A synthetic drug that has no effect on a receptor unless the endogenous substance accompanies it is called a(n) ______________
|
Agonist II
|
|
A synthetic drug that binds to the same receptor as an endogenous substance but causes no effect is called a(n) ______________
|
Pure antagonist
|
|
A synthetic drug that can bind to both inhibitory and excitatory receptors is called a(n) ______________
|
Agonist-Antagonist
|
|
A synthetic drug that binds to a different receptor as an endogenous substance and causes an opposite effect is called a(n) ______________
|
Physiologic antagonism
|
|
Chemicals can act as: agonist, antagonists, or both?
|
Both
|
|
What is an ED-50?
|
Dose that causes a specified effect in 50% of the population
|
|
What is a LD-50
|
Dose required to produce a specific toxic effect in 50% of animals
|
|
What organs/tissues represent the central compartment in volume of distribution?
|
1. Brain
2. Heart 3. Lungs 4. Liver 5. Kidneys 6. Endocrine glands |
|
What organs/tissues represent the peripheral compartment in volume of distribution?
|
1. muscle
2. skin 3. fat |
|
What percent of the central compartment is body mass?
How much of the cardiac output does it receive? |
1. 10% mass
2. 75% C.O. |
|
What percent of the peripheral compartment is body mass?
How much of the cardiac output does it receive? |
1. 90% mass
2. 25 % C.O. |
|
What is zero order kinetics?
|
A CONSTANT amt of drug is eliminated per unit of time
|
|
What is first order kinetics?
|
A constant FRACTION of drug is eliminated per unit of time
|
|
What does the alpha phase of first order kinetics represent?
|
Initial distribution of drug
|
|
What does the beta phase of first order kinetics represent?
|
The fractional elimination of the drug
|
|
According to kinetics, what is responsible for rapid recovery from induction drugs such as propofol, barbituates & non-barbituates?
|
The rapid distribution in the alpha phase
|
|
How much drug is left after 18 hours in the following scenario:
T1/2: 6 h Dose: 10 mg |
1.25 mg
|
|
How much drug is removed after 50 hours in the following scenario:
T1/2: ??? Dose: 160 mg After 30H: 20 mg How much is lost after 50H: ??? |
35 mg
|