Pharmacology Fundamentals: Drug Metabolism and Action

Vocabulary-style flashcards covering key pharmacological terms and concepts including drug barriers, efficacy, potency, and safety measures.

First-Pass Effect

The metabolism of a drug by the liver before it reaches the bloodstream, reducing the amount of active drug available.

Bioavailability

The percentage of a drug that reaches the bloodstream in its active form after administration.

Protein Binding

The attachment of a drug to blood proteins (mainly albumin). Only the unbound (free) drug can produce a therapeutic effect.

Blood-Brain Barrier (BBB)

A protective barrier that prevents many drugs and harmful substances from entering the brain.

Placental Barrier

A barrier between the mother's and fetus's blood. Some drugs can cross it and affect fetal development.

Half-Life (t)

The time required for the amount of a drug in the body to decrease by $50\%$.

Efficacy

The maximum effect a drug can produce, regardless of the dose.

Dose-Response Relationship

The relationship between the dose of a drug and the magnitude of its effect. Generally, increasing the dose increases the effect until the maximum effect is reached.

Onset

The time from drug administration until the drug begins to produce its effect.

Peak

The time when a drug reaches its highest concentration or maximum therapeutic effect.

Duration

The length of time a drug continues to produce its therapeutic effect.

Therapeutic Window

The range of drug concentrations in which the drug is effective without causing significant toxicity.

Therapeutic Index (TI)

A measure of drug safety. It compares the toxic dose to the effective dose. A higher TI means a safer drug.

Potency

The amount of a drug needed to produce a desired effect. A more potent drug requires a smaller dose.

Selectivity

A drug's ability to act on a specific target (receptor or tissue) with minimal effects on other parts of the body.

Side Effect

An expected, unintended effect that occurs at normal therapeutic doses. It may be mild or bothersome but is usually not harmful.

Adverse Effect

An unintended, harmful, or potentially dangerous reaction to a drug that may require treatment, dose adjustment, or discontinuation.