[REACTION KINETICS] First order and Zero order

Proverbs 16:3

Rate of Reaction

The ______ of a chemical reaction is the VELOCITY with which it occurs.

TRUE

TRUE OR FALSE:

Usually, only the parent (or pharmacologically active) drug is measured experimentally.

Rate of Reaction

The ______ of a reaction is determined experimentally by measuring the disappearance of a drug at given time intervals.

Order of Reaction

The ______ of a reaction is the way in which the concentration of a drug or reactant in a chemical reaction affects the rate.

Order of Reaction

It also refers to the way in which the concentration of a drug or reactants influences the rate of chemical reaction or processes.

Most drugs

[FIRST ORDER VS ZERO ORDER]

Drugs that undergo first order:

● Warfarin

● Heparin

● Alcohol (Ethanol)

● Aspirin

● Theophylline /Tolbutamide

● Phenytoin

📌Mnemonic: “WHAATP”

[FIRST ORDER VS ZERO ORDER]

Drugs that undergo zero order [5]

First-order kinetics

[FIRST ORDER VS ZERO ORDER]

Rate of metabolism: PROPORTIONAL

Zero-order kinetics

[FIRST ORDER VS ZERO ORDER]

Rate of metabolism: CONSTANT

First-order kinetics

[FIRST ORDER VS ZERO ORDER]

Rate constant units: PER TIME

Zero-order kinetics

[FIRST ORDER VS ZERO ORDER]

Rate constant units: AMOUNT PER TIME

First-order kinetics

[FIRST ORDER VS ZERO ORDER]

Drug loss: CONSTANT FRACTION

Zero-order kinetics

[FIRST ORDER VS ZERO ORDER]

Drug loss: CONSTANT AMOUNT

First-order kinetics

[FIRST ORDER VS ZERO ORDER]

Formula: In C = -kt + In Co

Zero-order kinetics

[FIRST ORDER VS ZERO ORDER]

Formula: C = -kt + Co

First-order kinetics

[FIRST ORDER VS ZERO ORDER]

CONSTANT FRACTION of elimination

Zero-order kinetics

[FIRST ORDER VS ZERO ORDER]

CONSTANT AMOUNT of elimination

First-order kinetics

[FIRST ORDER VS ZERO ORDER]

📌There is LESS drug than enzyme.

📌NO SATURATION occurs.

📌The enzyme will metabolize a CONSTANT FRACTION PER HOUR.

First-order kinetics

[FIRST ORDER VS ZERO ORDER]

There is LESS drug than enzyme.

First-order kinetics

[FIRST ORDER VS ZERO ORDER]

NO SATURATION occurs.

First-order kinetics

[FIRST ORDER VS ZERO ORDER]

The enzyme will metabolize a CONSTANT FRACTION PER HOUR.

Zero-order kinetics

[FIRST ORDER VS ZERO ORDER]

📌There is MORE drug than enzyme.

📌The enzyme will metabolize a CONSTANT AMOUNT PER HOUR.

Zero-order kinetics

[FIRST ORDER VS ZERO ORDER]

There is MORE drug than enzyme.

Zero-order kinetics

[FIRST ORDER VS ZERO ORDER]

The enzyme will metabolize a CONSTANT AMOUNT PER HOUR.