Pharm Equations Flashcards
1
Q
Volume of distribution (Vd)?
A
Vd = dose / plasma drug conc
2
Q
Half life?
A
t1/2 = 0.7 x Vd / Cl
3
Q
Clearance?
A
Cl = rate of drug elimination / plasma drug conc
4
Q
Alternative Cl equation?
A
Cl = Vd x Ke (elimination constant)
5
Q
Loading dose?
A
Cp x Vd / F (Cp = target plasma conc)
6
Q
Maintenance dose?
A
Cp x Cl / F
7
Q
Therapeutic index?
A
Median lethal dose / median effective dose
8
Q
Low Vd (4-8L)?
A
Blood
9
Q
Medium Vd?
A
ECF
10
Q
High Vd?
A
All tissues
11
Q
Drug types with low Vd?
A
1) Large/charged molecules
2) Plasma protein bound
12
Q
Drug types with medium Vd?
A
Small hydrophilic molecules
13
Q
Drug types with high Vd?
A
Small lipophilic molecules, esp if bound to tissue protein
14
Q
What happens to maintenance dose and loading dose in renal or liver dz?
A
1) Maintenance dose decreases
2) Loading dose is unchanged
