Table 1.

Summary of equations for pharmacokinetic parameters

Pharmacokinetic ParameterDefinitionEquation or Method of Calculation
FFraction of ip dose absorbedF = (Total dose − Amount of drug remaining in dialysate at the end of antibiotic dwell)/Total dose
kelPlasma elimination rate constantNegative slope of the log-transformed concentration versus time data obtained from plasma samples between 6 and 24 hours
t1/2, elPlasma elimination half-lifet1/2, el=ln2/kel
kpc 0–6Rate constant for distribution of drug from the peritoneal cavity between 0 and 6 hoursNegative slope of the log-transformed concentration versus time data obtained from peritoneal dialysate samples between 0 and 6 hours
t1/2, pc 0–6Distribution half-life in the peritoneal cavity between 0 and 6 hourst1/2, pc 0–6=ln2/kpc 0–6
t1/2, eqEquilibration half-lifet1/2, eq=ln2/(kel+kpc 0–6)
CLtotalTotal clearance from the systemic circulationCLtotal = (F × Dose)/AUCplasma 0–∞
AUCplasma 0–∞Area under the plasma concentration time curve between time 0 and infinityLinear trapezoidal rule between 0 and 24 hours; then, extrapolation from 24 hours to infinity was calculated assuming log-linear decline
AUC0–24Area under the concentration time curve between 0 and 24 hoursLinear trapezoidal rule between 0 and 24 hours
VdVolume of distributionVd=CLplasma 0–24/kel
CLplasma 0–24Plasma clearance between 0 and 24 hoursCLplasma 0-24 = (F × Dose)/AUCplasma 0–24
CLperitoneal 6–24Peritoneal clearance from 6 to 24 hoursEmbedded Image
CLnondialNondialysate clearanceCLnondial=(CLplasma 0–24)−(CLperitoneal 6–24)
  • ip, intraperitoneal.