Drugs Of Abuse Flashcards
What are the four core behaviors that define substance use disorder (SUD) according to DSM-5?
- Impaired control over drug use
- Compulsive use
- Continued use despite harm
- Craving
Which brain system is central to the drug-induced reward response and addiction cycle?
The mesocorticolimbic dopamine pathway, which includes the ventral tegmental area (VTA), nucleus accumbens, and prefrontal cortex.
What are the primary functions of the mesocorticolimbic dopamine pathway in addiction?
It mediates reward, motivation, salience of stimuli, and reinforcement, contributing to the craving and relapse cycle.
What is the Controlled Substances Act (CSA), and what does it regulate?
Enacted in 1970, it is U.S. federal policy for classifying substances with abuse potential into Schedules I–V, regulating their manufacture, distribution, and possession.
What defines a Schedule I drug under the CSA?
No accepted medical use in the U.S. and high potential for abuse. Examples: heroin, LSD, marijuana, MDMA, DMT, mescaline, psilocybin.
What is cocaine’s mechanism of action that contributes to its addictive potential?
Cocaine inhibits reuptake of dopamine, serotonin, and norepinephrine by binding to their transporters (especially DAT), increasing synaptic levels.
What are key CNS and cardiovascular toxicities of cocaine?
• CNS: seizures, psychosis, depression, hemorrhage
• CV: tachycardia, vasoconstriction, MI, arrhythmias, sudden death from cardiac arrest
What is the “crash” phase in cocaine withdrawal and when does it occur?
Occurs within 1–4 days after cessation. Characterized by anxiety, anhedonia, hyperphagia, and hypersomnolence.
What is the pharmacologic action of amphetamines that makes them addictive?
Amphetamines release dopamine and norepinephrine from presynaptic vesicles, and reverse the dopamine transporter (DAT), flooding the synapse with DA.
What are subjective and peripheral effects of amphetamines?
• CNS: euphoria, alertness, exhilaration
• Peripheral: increased BP, respiration, tachycardia, mydriasis, and sweating
What are common chronic effects of amphetamine or methamphetamine abuse?
Tachyphylaxis, psychosis (paranoia, hallucinations), aggression, anorexia, insomnia, poor dentition (“meth mouth”), and memory impairment.
What dental risks are associated with chronic methamphetamine use?
Xerostomia, bruxism, tooth decay, gum disease, and poor hygiene—together called meth mouth due to acidic drug, dry mouth, and high sugar intake.
What is MDMA (ecstasy), and how does it act in the brain?
A synthetic amphetamine analog that releases serotonin, dopamine, and norepinephrine, especially 5-HT, producing stimulant and empathogenic effects.
What are short-term effects of MDMA (ecstasy)?
Increased empathy, sociability, sensory enhancement, euphoria, mild hallucinations, jaw clenching, hyperthermia, and hyponatremia due to excess water intake.
What are long-term effects or risks of MDMA use?
Serotonin depletion, depression, memory loss, and risk of serotonin syndrome—especially when combined with SSRIs or MAOIs.
What is the pharmacologic action of nicotine?
Agonist at nicotinic acetylcholine receptors (nAChRs) in the CNS and peripheral ganglia, stimulating dopamine release and autonomic responses.
Why is nicotine highly addictive?
It causes rapid dopamine release in the nucleus accumbens, reinforcing behavior. Its short half-life and frequent dosing maintain addiction.
What is the mechanism of action of varenicline (Chantix) for smoking cessation?
Partial agonist at α4β2 nAChRs—reduces nicotine cravings and blocks its reinforcing effects.
What is bupropion’s role in smoking cessation?
An atypical antidepressant that inhibits norepinephrine and dopamine reuptake, helping reduce withdrawal symptoms and cravings.
What is the difference between classical hallucinogens and dissociative anesthetics?
Classical hallucinogens (e.g., LSD, psilocybin) act via 5-HT2A receptor agonism; dissociative anesthetics (e.g., PCP, ketamine) act via NMDA antagonism.
What is the mechanism of action of LSD?
Partial agonist at 5-HT2A receptors, especially in the cortex, altering perception, time sense, and cognition.
What are acute effects of LSD and other classic hallucinogens?
Sensory distortion, visual hallucinations, synesthesia, altered time perception, mydriasis, and possible panic or paranoia.
What are “flashbacks” and how are they related to LSD?
Recurrent perceptual symptoms (hallucinations or distortions) that occur after the drug has worn off—called hallucinogen persisting perception disorder (HPPD).
What is phencyclidine (PCP), and what is its mechanism of action?
A dissociative anesthetic and NMDA receptor antagonist causing hallucinations, agitation, aggression, and analgesia.
