Pharmacokinetics Flashcards
What is passive diffusion
Drugs can diffuse passively down concentration gradient from one side of membrane to other
Small molecules are more permeable so they can travel faster and easier
Solubility in lipid bilayer
What is facilitated diffusion
Passive and involves protein in membrane
Protein helps drug move across membrane
Relies on concetration gradient - needs higher concentration on one end than other
What is active transport
If drug is substrate for transport/carrier which pumps drugs back into lumen
ATP driven pumps
Occurs in brain, kidney etc
What is Absorption
Transer of drugs from site of administration to systemic circulation
What is bioavailability (F)
Fraction of dose that gets into systemic circulation
How do you calculate bioavailability (F)
F = Quantitiy of drug reaching systemic circulation as intact drug/ quantity of drug adminstered (i.e dose)
What is bioequivanelnce
2 drug preparations are bioequivalent if they have the same active ingredient and the rate of the active ingredient isn’t significantly different
What is the process of absorption after oral dose
Tablet dissolves
Pass across intestinal wall
Pass through portal vein
Pass through liver
