Pharmacokinetics
to Pharmacology
Action of body on drug
How you move it around changes with age
GFR and hepatic enzyme action are lower in neonates
- (Liberation)
- Absorption
- Metabolism (and genetic variation) (? for action and/or for excretion)
- Excretion (GFR or hepatic)
BSA
Action of body on drug
How you move it around changes with age
GFR and hepatic enzyme action are lower in neonates
- (Liberation)
- Absorption
- Bioavailability = the fraction of administered drug that reaches circulation
- = Area Under Curve (other) / Area Under Curve (IV) x Dose (IV) / Dose (other)
- Metabolism (and genetic variation) (? for action and/or for excretion)
- Excretion (GFR or hepatic)
- Plasma clearance = Volume / time (i.e Volume of distribution / half-life)
- First order elimination = fixed percent eliminated (i.e. half-lives)
- Zero-order elimination = fixed amount eliminated, (i.e. linear drop) only occurs with saturation (e.g. overdose)
- NO dose modification in organ failure
- Steady state concentration (95% of ultimate steady state) is reached after 5 half-lives
- Loading dose tries to achieve close to steady state but will generally under/overshoot and still take the 5 days
- Dose modification in organ dysfunction
BSA