A negative linear slope is indicative of Zero-Order Elimination Kinetics.

A negative linear slope is indicative of Zero-Order Elimination Kinetics.

• A. False
• B. Only during saturation
• C. Unrelated to elimination order
• D. True

Answer: (D)

Zero-order elimination means the body removes a constant amount of drug per unit time, so the concentration in the blood declines at a steady rate. When you plot concentration versus time, that constant rate shows up as a straight line with a negative slope. That straight, downward line is the signature of zero-order kinetics, distinguishing it from first-order elimination, where the decline is exponential and best seen as a straight line on a semi-log plot. Zero-order often occurs when metabolic pathways are saturated, but the key point is that a constant amount eliminated per unit time produces the linear negative slope.

Zero-order elimination means the body removes a constant amount of drug per unit time, so the concentration in the blood declines at a steady rate. When you plot concentration versus time, that constant rate shows up as a straight line with a negative slope. That straight, downward line is the signature of zero-order kinetics, distinguishing it from first-order elimination, where the decline is exponential and best seen as a straight line on a semi-log plot. Zero-order often occurs when metabolic pathways are saturated, but the key point is that a constant amount eliminated per unit time produces the linear negative slope.