Lecture 29 Flashcards
What is the definition of a drug?
any substance that when administered to a living organism, produces a biological effect.
What is pharmacology?
the study of how the function of living systems is affected by chemical agents
What is pharmacokinetics?
the study of absorption, distribution, metabolism and excretion of drugs
What is pharmacodynamics?
the study of effects of drugs and their mechanisms of action
What is Clinical pharmacology or Pharmacotherapeutics
the study of the use of drugs in the prevention and
treatment of disease.
What is toxicology?
the study of adverse effects of drugs
Describe how drugs target ion channels?
by altering the conductance of ion channels
examples of ion channel altering drugs?
local anesthetics
sedative-hypnotics
antiepileptics
G-protein-linked receptors and drugs
60 percent of drugs act upon G-proteins
Examples of drugs that use G protein linked receptors
albuterol- asthma (beta-2 agonist)
propranolol- hypertension (beta-anatagonist)
Example of enzyme-linked receptors?
receptor tyrosine kinase
What receptors are included in enzyme linked?
insulin receptor
epidermal growth factor receptor
What is the drug imatinib used for and what does it inhibit?
it is an effective treatment for leukemia
inhibits tyrosine kinase receptor
What do nuclear receptors do?
they regulate the expression of genes controlling metabolism and growth
What ligands bind to nuclear receptors?
steroid hormones
thyroid hormones
Vit D
examples of drugs that inhibit enzymes?
- aspirin
- ibuprofen
- omeprazole
What kinds of drugs are used to treat psychiatric disorders?
drugs that interfere with neurotransmitter transporters
Example of an anti-cancer drug that binds to tubulin
vinblastine
arrests cells in the metaphase stage
What are the two types of dose-response curves?
graded and quantal
How is the relationship between drug concentration and effect described on a graph
a hyperbolic curve
What does Emax mean?
the maximal response produced by a drug
What does EC50 mean?
the drug concentration that produces 50 percent of the maximal effect
What is Bmax?
the total concentration of binding sites
What is kD?
the equilibrium dissociation constant
occupy half the receptors
receptors affinity for the drug
if kD is low, affinity is high vice versa
What is efficacy?
the magnitude of the response a drug produces
What is potency?
is a measure of the concentration or amount of drug necessary to produce an effect of a given magnitude
What is an agonist?
a drug that binds to and activates a receptor in a way that brings about an effect
affinity and efficacy
What is an antagonist?
inhibits the action of an agonist but has no effect in the absence of the agonist
affinity but no efficacy
What is used to determine potency?
EC50
What is receptor antagonism?
A receptor antagonist binds to the same receptor to which the agonist binds
What is competitive antagonism?
bind to the agonist binding site on the receptor
competitive inhibitors can be….
reversible or irreversible
noncompetitive anatagonism or allosteric anatagonism
bind to the receptor at a site different from the agonist binding site
Emax is decreased
What is nonreceptor antagonism?
A nonreceptor antagonist does not bind to the
receptor to which the agonist binds.
What is physiological antagonism?
One drug opposes another drug, but through
different receptors
What is chemical antagonism?
A chemical antagonist reacts chemically with an
agonist to form an inactive product
full agonist?
produces a maximal response
partial agonist?
submaximal response
Inverse agonists?
reverse constitutive activity of a receptor
What is a quantal dose?
response relationship plots the fraction of the population that responds to a given dose of drug as a function of the drug dose
What is ED50?
effective dose
the dose at which 50% of individuals exhibit the
specified quantal effect
What is TD50?
The dose required to produce a particular toxic
effect in 50% of animals
What is LD50?
The dose required to cause death in 50% of
animals
What is therapeutic index?
the ratio of TD50, LD50, and ED50 for a therapeutically relevant effect
