Drug distribution Flashcards
What do some drugs pass and others don’t?
The blood-brain barrier
What is the main protein found in the blood?
Albumin
What is a drug that is ‘unbound’ to a protein?
Active
What is a drug that is ‘bound’ to a protein?
Inactive
What does a small change in amount of unbound drug mean?
A dramatic increase in available drug for body to use
What is the range above the therapeutic range called?
Toxcitiy/ toxic range.
What does the volume of distribution of a drug relate to?
level of lipid solubility
What is the ‘clearance’ of a drug?
breakdown and removal of drug.
What are the pathways in which a drug is excreted?
Renally, hepatic (kidneys), breath
What do you need to keep in mind with regard to drug excretion in patients?
Renal/ liver diseases/ problems.
What is meant by a drug’s half-life?
The time taken for plasma concentration of the drug to drop to half.
In general, how many cycles of the half-life does it take to wash a drug out of someone’s system?
5
What does a half-life depend on?
volume of distribution
rate of drug clearance.
What can increase toxicity?
prolongation of half-life, due to reduction in learance and increase in vol of distrbution
What is a less commonly thought about secretion pathway that also needs to be considered?
Biliary secretion.
