Introduction to ADME Lecture Notes

A collection of vocabulary flashcards derived from the lecture notes on ADME processes and factors affecting drug absorption, distribution, metabolism, and excretion.

ADME

Absorption, Distribution, Metabolism, Excretion; the processes by which drugs are absorbed, circulated through the body, chemically altered, and eliminated.

Bioavailability

The fraction of an administered dose of unchanged drug that reaches systemic circulation.

Phase I Metabolism

The chemical modification of a drug, typically through oxidation or reduction, to make it more reactive.

Phase II Metabolism

The process whereby Phase I metabolites are conjugated with larger groups to increase water solubility for excretion.

SLC Transporters

Solute Carrier transporters that facilitate the passive movement of molecules down their electrochemical gradient.

ABC Transporters

ATP-Binding Cassette transporters that mediate active transport of molecules using energy from ATP.

Plasma Protein Binding

The process where drugs bind to plasma proteins, affecting their distribution and pharmacological activity.

pKa

The pH at which a drug is 50% ionized, influencing drug solubility and permeability.

Ion Trapping

The process where ionized drugs become trapped in a compartment due to pH differences, affecting metabolism and excretion.

Henderson-Hasselbalch Equation

A formula used to calculate the pH of a solution in relation to the concentration of acid and its conjugate base.

Half-life

The time required for the concentration of a drug in the body to be reduced by half.

First-Pass Metabolism

The initial metabolism of a drug by the liver before it enters systemic circulation, which can significantly reduce bioavailability.

Metabolism Enzymes

Enzymes such as Cytochrome P450 that are involved in the metabolism of drugs, often resulting in the generation of metabolites.

Dissolution

The process where a solid form of a drug dissolves into a liquid, affecting its availability for absorption.

Log P

A measure of a drug’s lipophilicity or hydrophilicity, impacting the absorption route and formulation.

transport mechanisms

Methods used by cells to move substances across membranes, including diffusion, passive transport, and active transport.