From textbook

What is a drug?

A substance that alters the physiology of the body.

How is a drug typically defined?

As a substance that alters physiology but is not considered food or nutrients.

What does the term 'psychoactive drugs' refer to?

Substances that impact the nervous system to alter a person’s mood, perceptions, or level of consciousness.

What is the difference between a chemical name and a generic name of a drug?

The chemical name is the formal description of the drug's molecular structure; the generic name is a simplified, nonproprietary name.

What is a trade name in the context of pharmaceuticals?

The proprietary name given to a drug by the manufacturer, which is protected by patent.

What is the term for the concentration of a drug that produces a desired effect in 50% of individuals tested?

ED50, or median effective dose.

What does LD50 represent?

The median lethal dose of a drug, or the dose that kills 50% of subjects.

How is the therapeutic index of a drug described?

The ratio of the LD50 to the ED50; a higher TI indicates a safer drug.

What is pharmacokinetics?

The study of how a drug moves around the body, including absorption, distribution, and elimination.

What is first-pass metabolism?

Metabolism of drug molecules in the liver before they reach the systemic circulation, often reducing drug effectiveness.

What is the blood-brain barrier?

A selective barrier that prevents many substances in the blood from entering the brain tissue.

What are the three main routes of drug administration?

Oral, injectable (parenteral), and inhalation.

What role do enzymes play in drug metabolism?

They catalyze chemical reactions that modify drugs into metabolites for easier elimination from the body.

What is the difference between potency and effectiveness?

Potency refers to the amount of drug needed to produce an effect, while effectiveness refers to the maximum effect a drug can produce.

What is the primary effect of a drug vs. its side effects?

The primary effect is the intended therapeutic effect; side effects are unintended effects that may be harmful or helpful.

What is drug tolerance?

The need for increasing doses of a drug to achieve the same effect after repeated use.

What does the term 'cross-tolerance' mean?

Tolerance to one drug that diminishes the effect of another drug of the same class.

What is withdrawal in the context of drug use?

Physiological changes that occur when the use of a drug is stopped or reduced.

What is the physiological basis of tolerance and withdrawal?

Tolerance arises from homeostatic adjustments to compensate for drug effects, while withdrawal symptoms occur during the absence of the drug.

What is the therapeutic window of a drug?

The range between the minimum effective dose and the dose that produces adverse side effects.

How does the route of administration affect drug effects?

Different routes lead to varying rates of absorption and peak blood levels, influencing the intensity and duration of effects.