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.
What are three factors that needed to be thought about before administrating drugs?
physiology
disease states
other drugs
What does a prolonged half-life increase the chances of?
toxicity.
