Drug Dependence Flashcards
Psychoactive Drugs:
Drugs that can alter our consciousness, and perceptions.
• 4 main categories of psychoactive drugs: depressants, stimulants, hallucinogens, opioids
• Depressants/GABAergics
• Depressants are drugs that lower your body’s basic functions and neural activity, lower CNS activity (decrease arousal/stimulation in areas of our brain) ex. Decrease Heart rate, decreased BP, decreased processing/reaction time (makes us act/think slowly), etc. Three categories: alcohol, barbiturates, and benzodiazepines
o Vasodilate at low, vasoconstrictor at high
Alcohol
o The most popular depressant is alcohol.
Decreased inhibitions, so decreasing cognitive control
Lack of coordination, slurring of speech
Think more slowly, disrupt REM sleep (and form memories)
o Alcohol is a CNS depressant that is absorbed through the cell membrane.
o Barbiturates
– used to induce sleep or reduce anxiety (calm them down) Depress your CNS. Anesthesia or anticonvulsant (drugs that reduce seizures)
Not often prescribed due to negative side effects such as reduced memory, judgement and concentration, with alcohol can lead to death (most drugs w/ alcohol are bad)
-barbital
- high abuse potential
Benzodiazepine - anxiolysis with less sedation
o Benzodiazepines are the most commonly prescribed suppressant. Subscribed for same things as barbiturates - sleep aids (to treat insomnia) or anti-anxiety or seizures (anticonvulsant)
Enhance your brain’s response to GABA. They open up GABA-activated chloride (Cl-) channels in your neurons, and make neurons more (-) charged.
3 types: short, intermediate, and long-acting. Short and intermediate are usually for sleep, while long acting are for anxiety.
-zelam, -zolam, -zepam
Benzodiazepines and alcohol bind to a site on the GABAA receptor complex
Stimulants
• Stimulants are drugs that excite your CNS, increase HR/BP, alertness, more awake, more energetic. Can cause people to feel glittery. Examples include:
o Cocaine – can be used as a anesthetic/
o Vasodillate
o Effect is similar to stress, increased glucose metabolism in brain.
• Stimulate –stimulate or intensity neural activity/bodily functions.
• Range from caffeine to cocaine, amphetamines, methamphetamines, and ecstasy. In between is nicotine.
• Caffeine (adenosine receptors ANTAGONIST) can disrupt your sleep. Increases energy, can disrupt sleep for several hours
• Nicotine - Increase HR/BP. also disrupts sleep and can suppress appetite (why some people gain weight when they quit smoking)
o At high levels, nicotine can cause muscles to relax and release stress-reducing neurotransmitters (to counteract hyper alertness).
o Nicotine is a CNS stimulant, which works as an acetylcholine receptor agonist.
• Both caffeine and nicotine:
o Physiologically addicting.
o Withdrawal symptoms from both:
From coffee: irritability, difficulty concentrating, depression,
Nicotine: (more addictive than coffee) Anxiety, insomnia, irritability, distractibility
• Cocaine is even stronger stimulant – causes brain to releases so much dopamine, serotonin, and norepinephrine that it depletes your brain’s supply. Intense crash and very depressed when it wears off.
o Regular users can experience disturbances, emotional suspicion, convulsions, cardiac arrest, and respiratory failure.
• Amphetamines and methamphetamines also trigger release of dopamine, feeling of euphoria for up to 8 hours. Once effect wears off - experience irritability, insomnia, seizures, depression
o Meth is highly addictive.
o Long-term Meth addicts may lose ability to maintain normal level of dopamine because brain tries to adjust to intense highs.
o Amphetamines block the reuptake of dopamine, which stimulates an increase in the release of dopamine from the presynaptic membrane.
THC works on anandamide (innate cannabinoid). Increase dopamine and GABA activity.
Hallucinogens
• referred to as psychedelics
• Hallucinogens: These drugs cause hallucinations, altered perception/sensations.
• Many types of hallucinations. Some even have medical uses.
• Ecstasy/MDMA/Molly– synthetic drug between a stimulant and hallucinogen.
o Like stimulant - Increases dopamine and serotonin and euphoria. Also stimulates the body’s CNS. Effects include: high BP, dehydration, overheating/HYPOTHERMIA can cause death
Can damage neurons that produce serotonin (5% damage of raphei nuclei in midbrain), which has several functions including moderating mood. No serotonin = depressed mood
o Causes hallucinogen - hallucinations and heightened sensations, ex. artificial feeling of social connectedness and intimacy
• LSD – Prototypical hallucinogen. Interferes with serotonin, which causes people to experience hallucinations.
o Hallucinations are visual instead of auditory
• Marijuana is also a mild hallucinogen. Main active chemical is THC, which heightens sensitivity to sounds, tastes, smells.
o Like alcohol, (depressant) - reduces inhibition, impairs motor and coordination skills, perceptual skills
o Disrupt memory formation and short-term recall.
o Stays in body up to a week’s so regular users need less of the drug rather than more to receive the same high.
o Used as medicine to relieve pain and nausea
• Some hallucinogens are used for PTSD treatment (MOLLY). Allow people to access painful memories from past that’s detached from strong emotions – so they can come to terms with it.
o LSD modifies serotonin neurotransmission (DIRECT SERATONIN AGONIST), especially the 5-HT2 receptor family (x17 receptors).
o Dilation of pupil (mydiasis)
• Opiates/Opioids
o Opiates – natural, while Opioids - synthetic
o Like depressants: Decrease CNS function, decrease HR/BP, cause relaxation, induce sleep (hence can be used to treat pain and anxiety).
o BUT it is NOT a depressant. Work on different mechanisms at the neurochemical level
o Analgesic – reduce perception of pain
o Examples. Heroine, codine, morphine. Vicodin an oxycontin, oxycodone
o Used to treat pain because they act at body’s receptor sites for endorphins (mu opioid receptor).
o Different class than depressants, even though overlapping for anxiety, rest act on GABA receptors while opiates act on endorphin Receptors
o Lead to euphoria, why taken recreationally
o An opiate binds to opioid receptors by mimicking endorphins (direct agonists).
o Vasodilator, and pupillary constriction
o Die by respiratory failure
- increase of prescription pills available –> increase in opioid addiction
o Methadone, suboxone, naloxone, bupernorphin = treatment
• Cannabis (Marijuana)
• Cannabis (Marijuana) – a mix of all. Can be a hallucinogen and also be a depressant or a stimulant
o Active substance: THC
o Cannabis metabolites can be present in the blood of users for up to 3 months.
o Tolerance can increase the amount of cannabis needed for impairment and THC metabolites and many other constituents of cannabis accumulate in fat cells for three months or more.
Drug Dependence and Homeostasis
o HABITUATION –> For example, pretend you are cocaine addict and you are always in the same room when you inject yourself with cocaine. Your brain starts to recognize external cues like room, needles etc (the whole process of getting cocaine) before you get cocaine. Your brain tells body to get head start – lowers HR before you take drugs –this is why you need higher dose over time.
• What would happen if you get those cues and don’t get the drug? You get a crash. Your body is below homeostasis (lower HR/metabolism). No high (which would occur if you took the drug) to counteract the slowing down your body has created.
• If you’re in a new location but take same level of drugs, you might get overdose. This is because in the new location your body has not prepared by reducing HR/metabolism.
Per Oral route of entry
• Oral is ingesting something, one of slowest routes because goes through GI tract (FIRST PASS METABOLISM - 25% OF DRUG DIGESTED)– half hour to kick in. Ex. Pill, alcohol.
Inhalation/Insufflation
• Inhalation is breathing or snorting or smoking, because once you inhale goes straight to brain. Insufflation, inhaling drugs through the nose, is highly addictive but less addictive than drugs that are injected. – 10 seconds. faster Ex. Tobacco or cocaine .
IV injection
• Injection- most direct, intravenous means goes right to vein (heart pump & thoracic pump help circulate drug quickly to blood brain barrier). Takes effects within seconds. Fastest Can be very dangerous (likely to inject bacteria and unexpected toxins) especially when using an infected needle.
• Transdermal
• Transdermal – drug is absorbed through skin, ex. Nicotine patch. Drug in patch has to be pretty potent, released into bloodstream over several hours.
o Transdermal administration occurs slowly, since the drugs have to be absorbed through the skin before the effects can be felt.
• Intramuscular
• Intramuscular –needle stuck into muscle. Can deliver drugs to your system slowly or quickly.
o Ex: Quick Delivery - epiPen – given to someone experiencing an allergic reaction which starts closing airways. EpiPen delivers epinephrine quickly and allows airways to open). Usually on thigh because it has the most access points to blood vessels
o Ex: Slow Delivery Vaccines. Intramuscular delivery of vaccines is why your arm gets so sore after shots.
o Intramuscular injection is the fastest route of entry. Most abused drugs are injected intravenously, however.
