Pharmacokinetics II Flashcards
Define rectilinear plot
Both axis are normal
Define semi log plot
One axis is log
What is the alpha phase of first order elimination?
Drug is distributed from the central compartment to the peripheral compartment while also being eliminated
What is the beta phase of first order elimination?
Central and peripheral compartments are at equilibrium and elimination is only seen from central compartment
Name THREE mechanisms of elimination
Metabolism by liver
Excretion by kidneys
Excretion by biliary to faeces
Define clearance
Removal of the drug irreversibly from the systemic circulation
How do you calculate CL(total)?
CL (renal) + CL (non renal)
How do you calculate first order clearance?
CL(s) = Ke.Vd
What is the formula for elimination half life?
t(0.5) = 0.693/Ke
What is the salt factor?
The fraction of the administered dose that is the active drug
How do you calculate the single dose and name the components?
Cp = SFD / Vd
What is steady state?
Where the amount of drug administered is equal to the amount of drug eliminated
How do you calculate the Cp at steady state?
Cp = SFD / CL x τ
What is the time to steady state?
Roughly 5 times half life
How can you reach steady state faster?
Using a loading dose
