Table 2. Formulas for Calculating Dosing Regimens
| Elimination rate constant |
kel = ln(C1/C2)/(t2-t1) |
| Drug elimination half-life |
t1/2 = 0.693 / kel |
| Maximum time that can lapse between doses |
Tmax = ln (Cmax/Cmin) / K |
| Amount of drug to be administered during a dosing interval |
DM,max = (Vd/F)(Cmax-Cmin) |
| Dose per unit time |
DM,max / Tmax |
| Dose each interval |
(DM,max)(Interval) / Tmax |
| Loading dose |
DL = (Vd/F)(Css,max) |
| Accumulation ratio |
1 / (1-[1.2]Z) |
Cmax = maximum PDC (peak)
Cmin = minimum PDC (trough)
Css,max = maximum (target) PDC at steady-state (mg/ml)
Vd = volume of distribution (l/kg)
F = bioavailabiltiy (100% if IV)
Z = T / t1/2 (Interval/half-live)
