Substance Abuse

Question 1

Cannabis-Pharmacokinetics and Mechanism

Answer 1

• Rapidly metabolized by the liver to 11-0H-delta9-THC=active form.
• Then metabolized to 9-nor-COOH-THC=inactive form.
• Metabolites are excreted in urine and feces–detectable for many days.
• Reaches brain in 15-30 seconds and is 3-5x more potent when smoked. Oral: onset of action is ~30mins.
• Metabolized and redistributed in fat–slowly leaves body.
• Duration of action: 1-6 hours. 20% remains in the body after 5 days and is undetectable after 30 days.
• Acts on CB1 receptor, which is uniquely found in the brain in the cerebellum, hippocampus, and basal ganglia. Acts on Gi receptor to decreases adenylyl cyclase activity–>inhibits release of neurotransmitter.

Question 2

delta-9-tetrahydrocannabinol

Answer 2

-Active form on cannabis in the body

Question 3

Phencyclidine (PCP)

Answer 3

• Mechanism: NMDA Antagonist
• Rapid, complete absorption
• Act as sympathomimetic on autonomic and CV systems: tachycardia, hypertension, potentiation of catecholamines
• Tolerance
• CNS: small doses produce drunken state with numbness of extremities. Moderate doses-analgesia and anesthesia. Large doses-convulsions.
• Overdose: CNS manifestations include anxiety, aggression, hallucinations, dysphoria, convulsions, delirium. Sympathomimetic manifestations include tachycardia and hypertensive crisis.
• Treatment: Support vitals, gastric suction, acidify urine, diazepam/antihypertensive agent, haloperidol

Question 4

Ketamine

Answer 4

• Mechanism: NMDA Antagonist
• Like PCP
• CNS effects are less potent and has shorter duration of action

Question 5

LSD

Answer 5

• Mechanism of sensory effects: agonist/partial agonist action at 5-HT2 receptors
• Indoleamine
• Less than 1% crosses BBB
• Onset of 15-20 mins, with duration of 12 hours
• Sympathomimetic effects: tachycardia, increased BP, psychomotor stimulation
• Sensory and subjective effects: altered perception (especially visual), lability of mood, impaired judgment
• Displays tolerance and cross-tolerance
• Toxicity: hallucinations, anxiety, panic, and depersonalization. Lasts less than 24 hours, treat with quiet environment and BDZs for sedation.
• Flashbacks can occur days-years later

Question 6

MDMA (methylenedioxymethamphetamine)

Answer 6

• Phenethylamine; “Ecstasy”
• Induces feelings of well-being and connection, altered time perception
• Onset of action is 20-40 minutes; duration is 3-4 hours
• Effects: psychomotor stimulation, restlessness, bruxism, anorexia, sweating, tremor
• Hangover: anhedonia
• Neurotoxicity: potentially on serotonin neurons

Question 7

Gamma-hydroxybutyrate (GHB)

Answer 7

• Precursor and metabolite of GABA.
• May have it’s own receptor
• Can be made in the body from GBL
• Effects last about 3 hours
• Primarily a depressant–induces relaxation and tranquility, and interacts with alcohol
• Overdose: drowsiness, ataxia, nausea, vomiting
• Higher doses: loss of bladder control, temporary amnesia, clonus, seizures

Question 8

Toluene

Answer 8

• Model airplane glue

- Inhalant

Question 9

Salvia divinorum

Answer 9

• Kappa opioid agonist
• Perennial herb; leaves contain salvinorin-A.
• Used as psychedelic
• Short duration of action (20-45 minutes)
• Creates dream-like experience with open and closed-eyed visual
• High doses: dissociation, with fear, panic, and perspiration

Question 10

Amphetamine

Answer 10

• Stimulant; causes release of dopamine
• Psychological effects: mood elevation, increased alertness and attention span, psychotic symptoms
• Physical effects: Loss of appetite and weight, pupil dilation
• Withdrawal: mood depression, psychological craving, hunger, pupil constriction, fatigue

Question 11

Cocaine

Answer 11

-Same as amphetamine, only mechanism is blockade of dopamine reuptake

Question 12

Alcohol

Answer 12

• Sedative, CNS depressant; increase GABA activity
• Psych effects: Mood elevation, decreased anxiety, somnolence, disinhibition
• Physical effects: sedation, poor coordination, respiratory depression
• Withdrawal: Anxiety, insomnia, psychotic symptoms, tremor, seizures, CV symptoms. Should be hospitalized due to life-threatening effects.

Question 13

Benzodiazepenes

Answer 13

Similar effects to alcohol.
Used to treat alcohol withdrawal.
High safety margin unless combined with another sedative.

Question 14

Barbiturates

Answer 14

Similar effects to alcohol. Low safety margin so very dangerous in overdose

Question 15

Heroin

Answer 15

• Opioid
• Compared to medically used opioids, is more potent, crosses BBB more quickly, and has faster and more euphoric action.
• Psych effects: mood elevation, relaxation, somnolence
• Physical effects: sedation, analgesia, respiratory depression, constipation, pupil constriction
• Withdrawal: mood depression, anxiety, insomnia, sweating, fever, rhinorrhea, piloerection, stomach cramps and diarrhea, pupil dilation. (Death is rare)

Question 16

Methadone

Answer 16

• Opioid used to treat heroin addiction and prevent withdrawal symptoms
• Dispensed by federal health authorities without charge
• Oral; long duration of action
• Less euphoria and drowsiness

Question 17

Buprenorphine

Answer 17

• Opioid receptor partial agonist-antagonist (unlikely to cause respiratory depression)
• Blocks both withdrawal symptoms and, when combined with naloxone, the euphoric action of heroin.
• Prescribed or dispensed by trained physicians in private practice.
• Oral; long duration of action
• Less euphoria and drowsiness

Question 18

Cannabis-effects

Answer 18

• Effects: euphoria, memory impairment, perceptual and motor alterations (driving), cardiovascular (tachycardia, orthostatic hypotension, angina exacerbation), pulmonary (bronchodilation, lung irritant/bronchoconstriction, decrease alveolar macrophage activity, decrease ciliary function), reproductive effects (decrease testosterone, sperm count, gonadal weight, GnRH, and prolactin in females. Abnormal menstrual cycles).
• Psych. effects: Acute anxiety reaction, transient paranoia, schizophrenia exacerbation, amotivational syndrome. With high doses, can cause diffuse acute brain syndrme=clouding of consciousness and memory, perceptual and sleep disorders.
• Withdrawal: Restelessness, irritability, sleep difficulties, decreased appetite and nausea, craving.

Question 19

Cannabis-Therapeutic use

Answer 19

-Dronabinol–nausea, AIDS wasting syndrome
-THC-Cannabidiol mixture-MS pain treatment and cancer pain (only in Canada)
-Rimonabant=CB1 antagonist-weight loss drug
(Don’t memorize names)