Q - Absorption
Which crosses membranes better: ionised or non-ionised?
Non-ionised
What does a large Vd indicate?
Most of the drug is in tissues rather than plasma.
Name the four major types of protein drug targets.
Receptors, enzymes, ion channels, transporters.
What is the main purpose of drug metabolism?
To make drugs more water-soluble for excretion.
Which route avoids first-pass metabolism but is still non-invasive?
Transdermal or inhalation.
What is bioavailability?
The fraction of an administered dose that reaches the systemic circulation.
What protein mainly binds drugs in plasma?
Albumin.
What is an agonist?
A drug that activates a receptor to produce a response.
What is half-life (t½)?
The time taken for the plasma concentration of a drug to fall by 50%.
What is Phase II metabolism?
Conjugation of the drug with a polar molecule to make it more water-soluble.
Where does most drug absorption occur?
small intestine
Which route of administration has 100% bioavailability?
Intravenous (IV).
What is a prodrug?
A drug given in an inactive form that is metabolised into an active form.
Which organ contains CYP enzymes?
Liver
Will heart failure slow or speed up drug distribution?
Slow
Acidic drugs are more ionised with higher pH - True or False?
True
Will the half-life of a drug with a low volume of distribution (Vd) be shorter or longer
Shorter
What is the therapeutic range?
The range of drug concentrations in the blood that produces a desired effect without causing toxicity.
Will increasing the dose change the half-life of a drug?
No.
Which phase involves adding a large polar group to the drug?
Phase II.
Does sublingual administration avoid first-pass metabolism?
Yes
Which receives a drug faster: brain or skin?
Brain
What is the therapeutic index?
A measure of drug safety based on the ratio of toxic dose to effective dose.
What are phase I reactions?
Reactions in which a functional group is added or exposed
Will ionised drugs be excreted by the kidneys more easily or less easily?
More easily.