AUC₂₄First-order steady-state estimate
— mg·h/LDrug-specific meaning is not assigned automatically.
Pharmacokinetics · Steady state
Intermittent Infusion PK
Turn two post-distribution levels from one steady-state dosing interval into patient-specific first-order parameters and exposure estimates.
Evidence recordSources and method currentVersion 0.1 · Updated July 17, 2026
Step 1
Enter one steady-state interval
Private by design. Values are calculated on this device and are not saved or sent to analytics.
Step 2
Individual pharmacokinetic parameters
Elimination rateLog-linear slope
— hr⁻¹Derived only from the two entered concentrations.
Half-lifeln(2) ÷ k
— hrAssumes first-order elimination remains stable.
Clearancek × Vd
— L/hrPatient- and interval-specific model estimate.
Volume of distributionSteady-state infusion equation
— LSensitive to timing and the one-compartment assumption.
Extrapolated end-infusion peakBack-extrapolated
— mg/LNot a directly measured concentration.
Extrapolated pre-dose troughForward-extrapolated
— mg/LAssumes the next dose begins on schedule.
Accumulation factor1 ÷ (1 − e⁻ᵏτ)
—Steady-state one-compartment estimate.
No regimen is recommended.The tool does not calculate a replacement dose or interval. Verify administration history, sample times, renal trajectory, indication, cultures, MIC method, and the applicable institutional protocol.
Evidence packet
What this tool is based on
This versioned record keeps the citations, equation or decision rule, units, test coverage, intended population, and exclusions attached to the tool.
How evidence review works →Two-point method · Primary publicationHamilton et al. Two-point method for determination of aminoglycoside pharmacokinetic parameters.Clin Pharm. 1986;5(7):583–586. PMID: 3750369 ↗Method comparison · Validation studyDenaro et al. Comparison of Sawchuk–Zaske and Bayesian forecasting for aminoglycosides.Br J Clin Pharmacol. 1989;28(1):37–44. PMCID: PMC1379968 ↗Regulatory PK parameters · GuidanceFDA guidance: Pharmacokinetics in patients with impaired renal function.U.S. Food and Drug Administration. 2024. ↗
Intended population
Patients receiving a stable intermittent IV infusion regimen at steady state with two accurately timed post-distribution levels from the same interval.
Equation record
Two-level first-order elimination plus steady-state intermittent-infusion equations for Cmax, Cmin, Vd, CL, AUCτ, AUC24, and accumulation.
Unit handling
Dose uses mg; concentrations mg/L; all times hours; outputs include hr⁻¹, hours, L, L/hr, and mg·h/L.
Test coverage
Hand-calculated steady-state interval, extrapolated peak/trough, Vd, clearance, AUC24, accumulation, and timing-boundary rejection.
Do not skip
Limitations and exclusions
- Not valid without reliable administration and sample timestamps.
- Not valid for changing dose or interval, missed doses, non–steady state, rapidly changing renal function, dialysis, CRRT, ECMO, or other material extracorporeal clearance.
- Samples drawn during infusion or the distribution phase can substantially distort the one-compartment slope.
- AUC = dose/clearance assumes complete IV bioavailability and linear pharmacokinetics.
- No drug-specific target or replacement regimen is generated.
One clearly labeled, contextually relevant sponsor may support this reference area. Sponsorship will never interrupt inputs, obscure results, influence formulas, or imply clinical endorsement.
About this tool
Intermittent Infusion PK Calculator
Use this intermittent-infusion PK calculator to estimate patient-specific peak, trough, volume of distribution, clearance, and daily exposure from appropriately timed levels.
The workspace uses a transparent first-order, one-compartment intermittent-infusion model. Verify dose, infusion, sample times, distribution, and stability assumptions before interpreting the output.