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Chapter 1: Introduction - Vocabulary Flashcards

What is a Drug? Psychoactive Effects and Examples

  • A drug is a chemical compound that produces psychological, behavioral, or physiological effects.

  • Focus of the course: recreational drug use and potential abuse, as opposed to purely medical use; some drugs may start with medical use but evolve into recreational/abusive patterns (e.g., OxyContin and the opioid epidemic).

  • Psychoactive effects include:

    • Altered cognitions (thought processes)

    • Possible improvements or impairments in thinking

    • Behavioral consequences

    • Motor effects

    • Examples of effects: euphoria, hallucinations, increased libido, etc.

  • Some drugs are used initially for medical reasons but later used abusively; the course will discuss these patterns.

  • The organization of material typically follows drug categories, though many drugs produce multiple effects that cross category lines (e.g., MDMA). At lower doses, MDMA acts as a stimulant; at higher doses, it can have hallucinogenic effects, illustrating that drug effects can vary with dose.

  • The first drug discussed after introduction is alcohol because it is the most prominent recreational drug and driver of treatment-seeking; it also serves as a basis for introducing core concepts applicable to other substances (e.g., tolerance, substance use disorder concepts).

Drug Categories, History, and Study Data

  • After alcohol, the course will cover caffeine, nicotine (tobacco), cannabis, hallucinogens, inhalants, major stimulants (e.g., amphetamine, methamphetamine), sedative-hypnotics (barbiturates, benzodiazepines), opiates, and behavioral addictions (gambling use disorder and Internet use disorder).

  • Behavioral addictions are treated as a modern expansion of substance use disorder concepts, reflecting new diagnostic categories.

  • Historical perspective in each chapter: drugs have a long history of use, including natural substances from plants, later purified isolates identified by chemists (isolation of active compounds from plant sources).

  • Example: Cocaine

    • Coca leaves were chewed for stimulant effects for a long time in South America, but the pure substance cocaine was later identified and purified.

    • Albert Neiman is cited as isolating cocaine from coca leaves (per transcript).

  • General historical highlights mentioned in the transcript include: alcohol as one of the earliest drugs due to natural fermentation; hallucinogens with long religious/mystical use; stimulants used historically; cannabis use dating back to ancient times; cocaine isolation; heroin synthesis from morphine; cigarette-rolling machines affecting smoking prevalence.

  • Current use and surveys: the course references two major Canadian surveys to track drug use over time.

    • Ontario Student Drug Use and Health Survey (OSDUHS): conducted every two years since 1977; surveys Ontario high school students (grades 7–12).

    • Canadian Tobacco, Alcohol and Drugs Survey (CTADS): conducted every two years among Canadians aged 15 and older.

  • Key prevalence and health statistics cited in the lecture:

    • Lifetime risk of a substance use disorder in the Canadian population: 20\%

    • Annual deaths in Canada attributable to drug use: approximately 7.0 \\times 10^4 (i.e., 70{,}000)

    • Proportion of Canadians aged 15+ who consumed an alcoholic beverage in the past year: 80\%

    • Proportion who have exceeded guidelines for drinking: 20\%

    • Proportion who have used cannabis in the past year: 20\%

    • Proportion who have tried an electronic cigarette (e-cigarette): 15\%

    • Age distribution pattern: highest levels of use typically occur in the 18{-}25 age range, with use often tapering off after that.

  • Guidelines for alcohol consumption (updated in 2021 by the Canadian Centre on Substance Abuse):

    • The guidelines state that ext{two standard drinks or less} in a setting is not associated with adverse consequences.

    • Increasing consumption above this level increases risk.

    • A standard drink examples (as described in the lecture): one can of regular-strength beer; one glass of wine; a roughly 5$-$6\text{ oz} pour of wine; one mixed drink containing about 1.5\text{ oz} of distilled spirits.

    • If a person has two glasses of wine with a meal, that is within the guidelines; three to six drinks may increase risk; seven standard drinks per week is associated with substantially increased risk.

  • Other prevalence notes:

    • Approximately 15\% of Canadians have tried an e-cigarette.

    • About 20\% have used cannabis in the past year.

    • The highest prevalence is in the 18{-}25 age group; prevalence tends to drop with age.

  • Conceptual takeaway: a substantial portion of the population experiences some level of problematic use, yet only a small proportion seek treatment.

  • The term “substance use disorder” is preferred over the older term “addiction,” and the DSM defines it with criteria; in many cases, a diagnosis can be made with as few as 2 symptoms.

Names, Nomenclature, and Language About Drugs

  • Every drug typically has up to four naming forms:

    • Chemical name: identifies the exact molecule and its structural features (e.g., the chemical name for caffeine is 1,3,7\text{-trimethylxanthine}).

    • Generic (nonproprietary) name: a standard name used by multiple manufacturers (e.g., fluoxetine).

    • Trade (proprietary) name: brand name used by a single company (e.g., Prozac for fluoxetine).

    • Street name: slang terms used in the streets; these can vary by drug and region and may be derivatives of the trade name or describe the drug’s physical form or alleged effects (e.g., amphetamine street names: Benes or dexes; LSD called barrel acid; marketing terms like “the love drug”).

  • Examples used in the lecture:

    • Chemical name: 1{,}3{,}7{-}trimethylxanthine for caffeine.

    • Chemical name for heroin: \text{diacetylmorphine}, which indicates a relationship to morphine; heroin crosses the blood-brain barrier more easily due to the added acetyl groups.

    • Generic vs. trade examples: \text{fluoxetine} (generic) vs. \text{Prozac} (trade); \text{triazolam} (generic) vs. \text{Halcion} (trade); \text{diazepam} (generic) vs. \text{Valium} (trade).

  • The notes also emphasize that if a chemical name or a particular naming form is important for the lecture or exam, it will be bolded in the text notes.

  • Practical note: drug marketing and naming influence perception; street names may reference trade names, physical form, or marketed effects (e.g., “love drug”).

  • The lecture will also discuss the distinction between the four naming systems and how they relate to understanding pharmacology and regulation.

Pharmacokinetics and Pharmacodynamics: Basic Concepts (Introductory Overview)

  • Pharmacokinetics: what the body does to a drug across four main processes—administration, absorption, distribution, metabolism, and elimination. This is sometimes summarized as ADME (Administration, Absorption, Distribution, Metabolism, Elimination).

  • Pharmacodynamics: what the drug does to the body at the site of action, particularly interactions with receptors and resulting effects.

  • While the course is not a deep pharmacology course, a basic understanding of pharmacokinetics and pharmacodynamics is introduced because these processes influence the likelihood of recreational use, abuse potential, and adverse effects.

Routes of Administration: How Drugs Enter and Reach the Brain

  • The most common routes of administration:

    • Oral (swallowed): taken through the mouth and absorbed in the digestive system; drugs enter the circulation after absorption from the small intestine.

    • Mucous membranes (nasal, ocular, vaginal, rectal): absorption across mucous membranes; common in snorted cocaine, some liquid injections, or other topical administration.

    • Skin (transdermal): absorption through the skin (e.g., nicotine patches, certain caffeine or ADHD medication products).

    • Inhalation (pulmonary): inhaled into the lungs and absorbed quickly into the bloodstream; affects brain very rapidly; nicotine and THC are examples; inhalation leads to very fast brain entry (see times below).

    • Injection: various routes (intravenous, subcutaneous) directly into the bloodstream or beneath the skin; most common among recreational users for rapid effect; mainlining is a street term for intravenous injection; skin popping for subcutaneous injection.

  • The bloodstream and the blood-brain barrier (BBB) are the key pathways for drug effects; some drugs cross BBB easily (e.g., heroin) while others cross less readily (e.g., morphine is slower).

  • Inhalation and speed of onset are particularly important for abuse potential because they deliver effects to the brain rapidly.

Onset and Relative Speed to the Brain: Why Some Routes Are More Abusive

  • Time to brain after administration (approximate):

    • Inhalation: about 7{-}8\text{ seconds} to reach the brain.

    • Intravenous injection: about 15\text{ seconds} to brain (very rapid).

  • Because inhalation brings a drug to the brain faster than many oral routes, inhaled drugs tend to have higher abuse potential due to quicker onset and more immediate feedback.

  • Example: crack cocaine is cocaine that is smoked (inhaled) rather than snorted or injected; inhalation accelerates onset similar to other rapidly absorbed forms.

  • Inhalants (e.g., airplane glue, nitrous oxide) are absorbed via inhalation and may be used in ways such as huffing or bagging (inhaling from a bag).

Absorption Details by Route: Oral, Mucous Membranes, Skin, Inhalation, Rectal

  • Oral administration specifics:

    • Absorption largely occurs in the small intestine; the stomach is less favorable due to acidity.

    • Many drugs are bases; in acidic stomach, bases become ionized and are poorly absorbed; as they pass into the less acidic small intestine, they are less ionized and absorbed more readily.

    • First-pass metabolism: absorbed drugs pass from the intestine to the liver before reaching systemic circulation; a portion is metabolized on first pass, reducing bioavailability.

    • Fetal exposure: fetal blood drug concentration can be about 75\% of maternal concentration within about five minutes, due to placental transfer and limited fetal metabolism in early development; fetal exposure is a concern in pregnancy.

    • Liver function and age affect metabolism: young (fetal development) and elderly populations may have different metabolic capacities; in alcoholism, liver function may be severely compromised, altering metabolism.

  • Other absorption routes:

    • Mucous membranes (nasal, ocular, vaginal, rectal): rapid absorption; snorting cocaine cited as nasal absorption.

    • Rectal absorption: some substances can be administered via suppositories.

    • Skin: transdermal absorption (e.g., nicotine patches); certain molecules may be absorbed through skin (historical note about LSD and skin exposure during discovery).

    • Oral exposure examples: chewing gum (some absorption occurs in the mouth as well as through swallowing saliva), skin absorption examples linked to nicotine and caffeine gums.

  • Inhalation and gases/vapors:

    • Inhalation is a particularly efficient route for substances like nicotine and THC; inhalants include gases and vapors (e.g., nitrous oxide).

    • The inhalation route is associated with rapid brain uptake and higher abuse potential.

  • Injection details:

    • Intravenous (IV) injection delivers directly into a vein (common street term: mainlining).

    • Subcutaneous (under the skin) injection (street term: skin popping).

    • Shared needles and infection risk led to the creation of needle-exchange programs to reduce disease transmission.

Special Historical and Conceptual Notes on Drug Absorption

  • LSD: Albert Hofmann accidentally discovered LSD and absorbed through the skin; his initial experiments involved applying the compound to his skin and experiencing a profound psychedelic experience; a subsequent experiment with a small oral dose produced a dramatic effect.

  • Absorption through the skin is a historical curiosity that highlights how routes of administration influence effects and the discovery of drugs.

Practical Implications and Ethical/Health Considerations

  • Understanding pharmacokinetics and routes of administration informs about abuse potential, onset of effects, dependence risk, and routes that might lead to faster or more intense experiences.

  • Needle sharing increases risk for infectious disease; this influenced public health strategies such as needle-exchange programs.

  • Historical prevalence and current use data emphasize the public health impact of drug use and the importance of surveillance, prevention, and treatment programs.

  • The course emphasizes critical thinking about statistics (ballpark estimates vs. exact numbers), the interpretation of survey data, and the limitations of cross-survey comparability.

Summary of Core Takeaways for Exam Prep

  • The course uses text notes with bolded terms to guide emphasis, but exam questions can cover any material from lectures and notes.

  • In MCQs, focus on ballpark figures and general trends rather than exact numbers unless explicitly highlighted.

  • A drug is a chemical that produces psychoactive effects; drugs may start medically and evolve into misuse or addiction patterns.

  • Alcohol is the introductory drug because of its prominence and role in treatment-seeking; the alcohol chapter introduces foundational concepts applicable to other substances (e.g., tolerance, use disorder).

  • Drugs are not always confined to a single chapter; many have multi-faceted effects that cross categories depending on dose and history of use (e.g., MDMA).

  • Classification of drugs in the course includes major categories (alcohol, caffeine, nicotine, cannabis, hallucinogens, inhalants, major stimulants, sedative-hypnotics, opiates) and behavioral addictions (gambling, Internet use disorder).

  • Historical context shows humans have used drugs for a very long time; purification and isolation of active compounds marked a key turning point in drug development (e.g., cocaine, heroin synthesis).

  • Current-use data from large Canadian surveys illustrate broad usage patterns, health risks, and demographic trends (e.g., age groups, past-year use, and guidelines).

  • Key statistics to remember (as ballpark figures):

    • Lifetime substance use disorder risk: 20\%

    • Annual drug-use deaths in Canada: about 70{,}000

    • Past-year alcohol use among Canadians 15+: 80\%

    • Canadians exceeding drinking guidelines: 20\%

    • Past-year cannabis use: 20\%

    • Ever tried an e-cigarette: 15\%

    • Highest use generally in 18{-}25 age group

  • DSM terminology: “substance use disorder” is the current term; diagnosis can require as few as 2 symptoms.

  • Standard drink concept and Canadian guidelines (updated 2021): two standard drinks or less generally not associated with adverse effects; seven standard drinks per week increases risk; examples of standard drinks include beer, wine, and mixed drinks with specified amounts of alcohol.

  • Routes of administration and pharmacokinetics/pharmacodynamics shape how quickly a drug acts, how it reaches the brain, and its potential for abuse and harm. Inhalation stands out as a route that accelerates brain entry and can enhance abuse potential compared with slower routes like oral intake.

Example Key Terms and Concepts to Memorize (with LaTeX)

  • 1{,}3{,}7{-}\text{trimethylxanthine} (chemical name for caffeine)

  • \text{diacetylmorphine} (chemical name for heroin)

  • MDMA: \text{Methylenedioxymethamphetamine}, also known as \text{MDMA} (dual stimulant/ hallucinogen profile depending on dose)

  • Standard drink examples: ext{beer (one can)}, ext{wine (one glass)}, ext{distilled spirits (one and a half ounces)}

  • Fetal exposure example: 75\% of maternal concentration in fetal blood within five minutes

  • Onset times: 7{-}8\text{ seconds} (inhalation to brain), \approx 15\text{ seconds} (IV to brain)

  • DSM criterion threshold: 2 symptoms for substance use disorder diagnosis