1.2 - Pharmacokinetics Flashcards
How long does it take a drug to completely clear from the system? What about to reach steady state?
4-5 half lives
A drug has a half life of eight hours. How long does it take to reach steady state during continuous same dose administration?
32-40 hours
Magnitude of steady state level (Concentration at steady-state or CSS) is determined by what?
[]ss = (Infusion rate/dosage interval)(F) / clearance
What can be done to decrease the amount of time it takes a drug to reach steady state?
Administer a loading dose
What do emollients or cathartics do?
Changes in surface tension
What do mineral oil, emollients, cathartics and activated charcoal have in common?
They are drugs that physically change the environment instead of acting on receptors.
What does activated charcoal do when swallowed?
Adsorbs other drugs to prevent overdose when taken in high quantities.
What is the word for something that binds with and interacts with a receptor?
A ligand
What is meant by affinity of a receptor for a drug?
The probablity of a drug to be occupying a reception at any given instance - the force of attraction between a receptor and a drug.
What is meant by selectivity of a drug?
The degree to which a drug acts on a given target relative to other sites.
What is meant by agonism?
When binding to the receptors results in a pharmacological response.
What is meant by antagonism?
When a drug’s binding to a receptor results is no pharmacological response, but inhibits another agonist from binding.
Is antagonism in drugs reversible?
It can be both reversible and irreversible. If it is irreversible, the receptor must be replaced
What is efficacy of a drug? Which axis can it be seen on a graph?
The largest response that a drug can produce (intensity of the body’s response to the drug) - y axis
What is the potency of a drug?
The amount of a drug that must be given in order to elicit an effect - x axis
