Zero Order Kinetics

It involves constant fraction/ amount of drug eliminated per unit time.

Example:-

Suppose, In plasma 500 mg PCM is present and 20 mg of the drug is eliminated per hour.

Therefore,

Therefore, from above we can say that Zero Order Kinetics is independent of plasma drug concentration. It doesn't matter drug is 500 mg or 480 mg, the concentration of drug elimination will be the same or we can say elimination is independent of plasma concentration.

• Clearance is more at low Plasma concentration.
• Clearance is low at high Plasma concentration.

Very Fewer Drugs undergo Zero Order Kinetics

Learn it by simple trick " Zero WATT Power".

ZERO -   Zero Order Kinetics

W       -    Warfarin

A        -     Alcohol

T        -     Tolbutamide

T        -    Theophylline

Power -    Phenytoin