Non-Compartmental Analysis
This interactive module demonstrates non-compartmental analysis (NCA) techniques for antimicrobial pharmacokinetic data analysis. Learn how to calculate key PK parameters directly from concentration-time data without assuming a specific compartmental model.
Patient Generator
- Age: - years
- Sex: -
- Height: - cm
- Weight: - kg
- Creatinine: - mg/dL
Medium (Standard Oral)
PK Parameters
0.8
0.1
0.7 L/kg
0.8
Dosing
0 mg
250 mg
24 hrs
10 days
Loading interactive chart…
20 mg/L
5 mg/L
| Subject | Drug Name | Age | Sex | Ht (cm) | Wt (kg) | BMI | IBW (kg) | Adj IBW (kg) | Creatinine (mg/dL) | CrCl (mL/min) | Loading Dose (mg) | Dose (mg) | Interval (hrs) | Duration (days) | Clearance (L/h) | Volume (L) | Fraction Unbound | Vss,u (L) | Bioavailability | Half-life (h) | Css,avg | AUC0-24h | Cmax | AUC/Efficacy | Cmax/Efficacy | Time>Efficacy (%) |
|---|
Non-Compartmental Analysis (NCA) Fundamentals
Model-Independent Approach: NCA calculates pharmacokinetic parameters directly from observed concentration-time data without assuming a specific compartmental model. This makes it ideal for regulatory submissions and clinical practice where model assumptions may not hold.
Key NCA Parameters: - AUC (Area Under the Curve): Total drug exposure calculated using the trapezoidal rule - Cmax: Maximum observed concentration - Tmax: Time to maximum concentration
- Clearance (CL/F): Dose/AUC for extravascular administration - Terminal Half-life: Calculated from the terminal elimination phase
Advantages of NCA: - No model assumptions required - Robust to sparse sampling - Regulatory gold standard - Less prone to bias than compartmental methods
Clinical Applications: NCA is particularly valuable for: - Bioequivalence studies - Dose proportionality assessments - First-in-human studies - Population PK analysis input data
Blood Sampling Strategy
In this simulation, blood samples are collected every 1 hour to provide a detailed view of how pharmacokinetic data is collected in clinical practice. This sampling frequency allows us to:
- Capture both peak and trough concentrations
- Observe the full absorption and elimination phases
- Reduce the burden on patients compared to more frequent sampling
- Provide sufficient data points for pharmacokinetic analysis
Simplified Pharmacokinetic Model
This simulation uses a simplified one-compartment model with first-order absorption that focuses on the minimum essential parameters needed to generate a multiple dosing pharmacokinetic plot:
Essential PK Parameters: - Clearance (CL): Automatically calculated from patient’s creatinine clearance using Cockcroft-Gault equation - Volume of Distribution (Vd): Drug-specific volume per kg multiplied by patient weight - Bioavailability (F): Fraction of dose reaching systemic circulation
Patient-Specific Factors: - Creatinine Clearance: Calculated using Cockcroft-Gault: CrCl = [(140 - age) × weight × (0.85 if female)] / (72 × serum creatinine) - Weight-Based Dosing: Volume of distribution scales directly with patient weight
Dosing Parameters: - Dose: Amount of drug administered per dose - Dosing Interval: Time between doses - Treatment Duration: Total length of treatment
This approach incorporates key patient-specific factors (age, sex, weight, creatinine) while maintaining the core functionality needed to understand multiple dosing pharmacokinetics and the clinical application of the Cockcroft-Gault equation.
Test your understanding by calculating the following parameters for the current patient:
1. Creatinine Clearance (mL/min):
2. Adjusted Body Weight (kg):
3. Volume of Distribution of Unbound Drug (L):
4. Time to Steady State - tss (hours):
5. Average Steady-State Concentration - Css,avg (mg/L):