Chapter 5 - Actions of Drugs Lecture Flashcards

Vocabulary-style flashcards covering neurotransmitters, drug naming conventions, categories, experimental design, dosing, administration routes, and types of tolerance from the lecture notes.

Acetylcholine

A neurotransmitter involved in various bodily functions including muscle activation and memory.

Dopamine

A neurotransmitter associated with pleasure, reward, and motor control.

Norepinephrine

A neurotransmitter that plays a role in arousal, alertness, and the "fight or flight" response.

Serotonin

A neurotransmitter involved in mood regulation, sleep, and appetite.

GABA (Gamma-Aminobutyric Acid)

The primary inhibitory neurotransmitter in the central nervous system.

Glutamate

The primary excitatory neurotransmitter.

Endorphins

Naturally occurring opioids that reduce pain and enhance pleasure.

Chemical Name

A complete chemical description of the drug's molecule; for example, N-acetyl-p-aminophenol.

Generic Name

The official or legal name of a drug listed in the United States Pharmacopoeia (USP); for example, acetaminophen.

Brand Name

A specific drug or formulation trademarked by a manufacturer that can be patented for 20 years; for example, Tylenol®.

Stimulants

Substances that produce wakefulness and a sense of energy, including Cocaine, Amphetamine, and Caffeine.

Depressants

Substances that slow down nervous system activity, including Alcohol, Benzodiazepines, sedatives, sleeping pills, and inhalants.

Opioids (Narcotics)

Substances used to reduce pain, such as Morphine, Codeine, Heroin, and Oxycodone.

Hallucinogens

Substances that produce altered perceptions, such as Psilocybin, LSD, and Ayahuasca.

Psychotherapeutics

Drugs used to treat symptoms of mental disorders, such as Cymbalta and Abilify.

Nonspecific Effects

Effects deriving from the user’s unique background, expectations, perceptions, and environment rather than the chemical itself.

Placebo Effects

A type of nonspecific effect produced by an inactive chemical that the user believes to be a drug; important in treating pain and major depression.

Specific Effects

Physical and behavioral changes that depend solely on the presence of a chemical at specific concentrations.

Double-blind experiment

A procedure where neither the participants nor the researchers know who receives the active drug or placebo to control for nonspecific effects.

Dose-Response Curve

A graph illustrating the relationship between a range of drug doses and the resulting clinical or behavioral effects.

Threshold

The absolute lowest dose of a drug at which an observable effect is first detected.

Safety Margin

The numerical difference between the dose that produces the desired therapeutic effect in most patients and the lowest dose producing an unacceptable toxic reaction.

Potency

The specific amount of a drug required to produce a chosen effect.

Side Effects

Any unintended effects that occur alongside the therapeutic effects.

Effective Dose ($ED_{50}$)

The dose produced a meaningful effect in 50% of the test subjects.

Lethal Dose ($LD_{50}$)

The dose that results in death for 50% of the test subjects.

Therapeutic Index

A ratio used to determine safety, calculated as $\text{Therapeutic Index} = \frac{LD_{50}}{ED_{50}}$.

Oral Administration

Ingestion by mouth involving absorption via the gastrointestinal tract; provides safety through nausea or vomiting reflexes.

Intravenous (i.v.)

The fastest means of injection delivered directly into the vein; heroin reaches the brain in approximately $15\,\text{seconds}$ through this method.

Intramuscular (i.m.)

Injection delivered to large muscles; slower than i.v. but faster than s.c.

Subcutaneous (s.c. or sub-Q)

Injection inserted just under the skin with the slowest absorption rate of all injections due to fewer capillaries.

Inhalation

Drug taken as gas or vapor; rapid onset moves from lungs to brain in $5-8\,\text{seconds}$, faster than i.v. injections.

Insufflation

Absorption through mucous membranes that bypasses the liver and avoids "first-pass metabolism."

Biotransformation

The process by which enzymes in the liver break down drugs into metabolites.

Drug Deactivation

The process of breaking down a drug in the body to terminate its action and prepare it for excretion, mainly occurring in the liver.

CYP450 Enzyme Family

Liver enzymes crucial for metabolizing drugs by inactivating various chemicals through biotransformation.

Active Metabolites

Forms of a drug that remain pharmacologically active after metabolism, continuing to exert therapeutic or side effects.

Potentiation

Effects that are significantly greater than the sum of the individual effects when two or more drugs are taken together.

Cross-Tolerance and Cross-Dependence

Occurs when different drugs bind to the same receptors, making effects interchangeable and allowing one drug to reduce withdrawal symptoms of another.

Drug Disposition (Pharmacokinetic) Tolerance

Reduced drug effect due to increased metabolism or excretion caused by induced metabolic enzymes.

Behavioral Tolerance

When users learn to adjust their behavior to compensate for drug effects, maintaining function despite impairment.

Pharmacodynamics Tolerance

Reduced sensitivity of receptors at the synapse, resulting in less effect from the same drug dose.

Metabolic Tolerance

A type of tolerance related to drug disposition (pharmacokinetic) tolerance by affecting drug metabolism.

Cellular Tolerance

A type of tolerance related to pharmacodynamic tolerance reflecting changes in receptor sensitivity.