45 terms
Pharm1 - Block3 - Gen Pharm 5
Therapeutic range may be narrow, and in this case what is key to understand
Size of dose must be smaller to prevent exceeding therapeutic range
Therapeutic range may be wider, and in this case what is key to understand
Size of dose may be larger and still not exceed therapeutic range
Range at which drug is most beneficial to the psecific patient
Therapeutic range
Therapeutic range may be achieved quickly via the use of
Loading dose
Steady state of a drug is determined by half life of drug, and so dosage of drug that results in steady state within the therapeutic range is called
Therapeutic dosing
Macromolecular component of the cell to which a drug binds to produce it's effect
Receptor
Maximum effect of the drug may be achieved without activating
all the receptors
Ability of the drug to bind to the receptors (nothing more)
Affinity
Ability of drug to activate receptor and produce response
Intrinsic activity (of drug)
Drug which has affinity for, and intrinsic activity of, a receptor is called an
Agonist
Drug which binds to receptor and activates it, but produces receptor activity that is the opposite of what the agonist drug would produce
Inverse agonist
Prominent example of inverse angonists
Antihistamines
Drug which has affinity for the receptor, but no intrinsic activitiy or inverse agonist properties
Antagonist
Drug which activates the receptor, but has submaximal intrinsic properties by comparison
Partial agonist
When a partial agonist is given along with a pure agonist, the partial agonist will have what effect
Antagonism of the pure agonist
Greatest efficacy on a dose response curve is achieved by
Agonist
Less efficacy on a dose response curve is achieved by
Partial agonist
Invese agonist
Invese agonist
Zero efficacy on a dose response curve is achieved by
Antagonist
If an agonist and an allosteric activator are combined, what will be the result on the dose response curve
Exceeds the agonist alone (A+C)
If an agonist and a competitive inhibitor (partial agonist) are given together, what will be the result on the dose response curve
Same efficacy as agonist alone, but the potency is lower
If an agonist and an allosteric inhibitor are given together, what will be the result on the dose response curve
Efficacy is greatly diminished, but potency is same
Receptors with the fastest physiological action
Ion channels
Receptor which results in either opening an ion channel or production of second messengers via intermediary proteins
G-protein coupled receptor
Receptor which results only in production of secondary messengers (at the membrane)
Kinase-linked receptor
Receptor that results in the production of second messengers at the nucleus
Nuclear receptor
Three important ligands that can act on nuclear receptors
Steroids
Vita D
Thyroxine
Vita D
Thyroxine
Graded dose response curves display which two properties of the drug in question
X = Potency
Y = Efficacy
Y = Efficacy
Amount of drug needed to achieve EC50%
Potency
Dose required to produce 1/2 of the maximum response
EC50%
(low EC50% = high potency)
(low EC50% = high potency)
Dose required to occupy half of the receptors present
Kd
(low Kd = high affinity)
(low Kd = high affinity)
The maximum response of a drug (upper limit of drug response curve)
Efficacy
If two drugs have the same efficacy and potency, but one has a faster response to that efficacy, the slope on the drug response curve will be
Steeper
A drug which produces a steeper drug response curve is said to have a greater
Dose range
Ratio of median lethal dose (LD50), and median effective dose ED50) equals
LD50 = dose that is lethal in 50% of the population
ED50 = dose that is effective in 50% of the population
LD50 = dose that is lethal in 50% of the population
ED50 = dose that is effective in 50% of the population
Therapeutic index/ratio
The clinical value of the Therapeutic index/ratio of a drug is essentially
Represents the safety of a drug
Therapeutic index is represented on which types of graphs
Quantal dose response curves
(Cummulative frequency distribution: is the frequency of occurance of values of a phenomenon)
(Cummulative frequency distribution: is the frequency of occurance of values of a phenomenon)
Quantal dose response curves display the cummulative freuncy distribution for various doses of drugs in the population tested, and so the cummulative frequency distribution for the therpeutic effect of the drug and the lethal effect of the drug can be compared in order to establish which values
ED50% and LD50%
Drug which binds to a different receptor molecule and produces an effectt aht is opposite to that produced by the drug it antagonizes
Physiological Antagonist
Another name for an antagonist
Pharmacological antagonist
An antagonist that must compete to bind to the same receptor as the agonist
Competitive/Reversible antagonist
Competitive/Reversible antagonists have what effect on the agonists activity
Reduces the potency of the agonist, not the efficacy of the agonist
Competitive/Reversible antagonists have what effect on the position of the drug response curve of a dosage
Causes a parallel shift in the drug response curve towards a higher concentration
Antagonists that bind irreversibly to a site other than that of the agonist
Noncompetitive/Irreversible antagonists
Noncompetitive/Irreversible antagonists have what effect on the agonists activity
Reduces the efficacy of the agonist
Noncompetitive/Irreversible antagonists have what effect on the position of the drug response curve of a dosage
Causes a nonparallel shift in the drug response towards a lower efficacy