Pharmacokinetics Flashcards
Bioavailability
(F), fraction of the dose that reaches the systemic circulation
F = amount in the circulation/total amount administered
First pass effect
Drugs pass through the liver where metabolism can occur. the more metabolism, the more bioavailability is reduced
Bioequivalence
two drug preparations with the same active ingredients at the same amount and delivered by the same route of administration and the extent and rate of drug delivery to the circulation are the same
Redistribtion
Drug being delivered to other organs from its site of action
Therapeutic window
Concentration of a drug in the body that is high enough to produce the desired effect with a minimum of toxicity
Volume of distribution
A measure of the apparent space in the body available to contain the drug, based upon the assumption that the concentration of drug throughout the body is the same as its concentration in the plasma
Clearance
rate of elimination/concentration, units are liter/min
Rate of elimination
the rate a drug is eliminated from the body…
Half-life
the time it takes for half the quantity of a first order drug to be eliminated
Loading dose
a big initial dose
Maintenance dose
a regular dose to keep concentrations in the therapeutic window
Major carrier for acidic drugs
Albumin, decreased by severe liver disease
Major carrier for basic drugs
Alpha1-acid glycoprotein, increased by immune activation (Crohn’s disease)
Organic-anion transporting polypeptide (OATP)
Remove the drug from the endothelial cell back into the blood
P-glycoprotein
Remove the drug from the endothelial cell back into the blood
