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Kinetics Calculator

First‑order, zero‑order & Michaelis‑Menten elimination models

Elimination Models

Model Selection

Rate proportional to concentration – constant half‑life

Initial Conditions

Examples

Results

Clinical Implications

  • • First‑order: Safe, predictable elimination; dose proportional [citation:7]
  • • Zero‑order: Risk of accumulation at high doses; small dose changes can cause large concentration swings [citation:7]
  • • Mixed kinetics: Requires therapeutic drug monitoring (phenytoin, theophylline)

Model Comparison

ParameterFirst-OrderZero-Order
Ratek·CV_max
Half-lifeConstantVariable
ExamplesMost drugsEthanol, Aspirin (high dose)