Formulas
Urinary creatinine clearance in a 12-hour urinary collection was
calculated using the below equation:
12-hour creatinine clearance (ml/min) =\(\frac{\text{urine\ volume\ }\left(\text{mL}\right)\ \times\ urine\ creatinin\ (\frac{\text{mg}}{\text{dL}})}{\text{serum\ creatinin\ }\left(\frac{\text{mg}}{\text{dL}}\right)\ \times\ collectin\ time\ (min)}\)
The PK parameters of meropenem were calculated according to the
following equations:
CL (L/hr) =\(\frac{[Dose/\ T]}{\text{Css\ ave}}\text{\ \ \ \ }\)
K (min-1) =\(\frac{\ln[Cpeak\ /Ctrough]\ }{t}\text{\ \ \ \ }\)
Vd (L) =\(\ \frac{\text{CL}}{K}\)
T1/2(hr) = \(\frac{0.693}{K}\)
”CL” is clearance of meropenem, ”K” is elimination rate constant and”
T1/2” is terminal half-life. Css ave is the average steady-state
concentration of meropenem. “Ƭ” is the dosing interval and ”t” is the
time interval between the measurements of Cpeak and Ctrough.