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Pharmacodynamic Emax Model Calculator
Model drug effect using stimulatory, sigmoid, and inhibitory Emax/Imax equations
PharmacyFreak.com · Educational Tool
Model Inputs
Active Formula
E(C) = E0 + (Emax × C) / (EC50 + C)
µM ↔ mg/L Conversion
Core Parameters
Single-Point Calculation
💊 Dose → Concentration Helper
Simplified estimate: C₀ = (Dose × F) / Vd — not a full PK model.
Enter dose, Vd, and F to estimate concentration.
Results
Live
E(C) — Predicted Effect
—
%
% of Emax Achieved
—
%
E0 (Baseline)
—
%
ΔE (Change from Baseline)
—
%
Detailed Calculation ▶
Enter values to see breakdown.
🔁 Reverse Solver — Find C for Target Effect
Enter a target effect above.
Effect–Concentration Curve
Curve Generator
| C (ng/mL) | E(C) (%) |
|---|
Understanding the Parameters
E0 — Baseline effect without any drug. This anchors the curve.
Emax / Imax — The maximum possible drug effect (or inhibition). Represents the ceiling of drug action.
EC50 / IC50 — Potency parameter. The concentration at which 50% of maximum effect is achieved. Lower = more potent.
Hill coefficient (γ) — Shape parameter. γ = 1 gives a simple hyperbola. γ > 1 creates a steeper sigmoidal curve. γ < 1 flattens it. Clinically, γ values of 1–3 are common.
Note: These are simplified equilibrium models. They don't account for time-dependence, active metabolites, or receptor kinetics.
⚠ Educational tool only. Validate all results with clinical context and pharmacometric modeling standards.
