Drugs of Abuse 2

Question 1

What are sedative hypnotics?

Answer 1

CNS depressant that has a range of magnitude depending on the dose from anti-anxiety to sedation to hypnosis and finally, general anesthesia

Question 2

Sedative Hypnotic method of action

Answer 2

increases inhibitory signals from GABA neurons which decreases glutamate signals; GABA causes inhibition by selectively opening chloride channels resulting in hyperpolarization and decreased ability for post-synaptic neuron transmission; sedative hypnotics bind to different parts of chloride channels in CNS and modulate their activity

Question 3

Examples of sedative hypnotics

Answer 3

Benzodiazepines, Flumazenil, Zolpidem and the Z drugs, Barbituates, Gamma-hydroxybutyric acid (GHB), Buspirone

Question 4

Benzodiazepines and their pharmacology

Answer 4

among the most widely prescribed drugs in the world and activates the benzodiazepine receptor which increases the frequency of the opening of the chloride ion channel; normally taken as tablet or capsule (sometimes IV) and have a high therapeutic index

Question 5

Short-term effects of Benzodiazepines

Answer 5

CNS- relaxation, calmness, relief from anxiety and tension, and drowsiness, lethargy, fatigue, impairment of thinking and memory
Lungs- respiratory depression
Motor- skeletal muscle relaxation and impairment of motor coordination
minimal REM suppression and anti-convulsion

Question 6

Long-term effects of Benzodiazepines

Answer 6

varies btwn individuals; some can demonstrate symptoms of chronic sedative-hypnotic intoxication (impaired thinking, poor memory and judgment, disorientation, slurred speech, incoordination)

Question 7

Pregnancy and elderly considerations with Benzodiazepines

Answer 7

crosses placenta and secretes into milk causing fetal abnormalities and sedation/death
metabolized slower in elderly leading to cognitive dysfunction and over-sedation

Question 8

Abuse potential and dependence with Benzodiazepines

Answer 8

low abuse liability and inherent harmfulness due to high therapeutic index (leads to a lot of overdose w out death), some tolerance and a high degree of cross tolerance, low dependence and addiction can occur

Question 9

Flumazenil

Answer 9

benzodiazepine receptor antagonist that blocks the effects of benzos and used as an antidote for benzo overdose

Question 10

Zolpidem and the Z drugs

Answer 10

bind to subset of GABA receptors causing sedation and disturb REM sleep even less

Question 11

Barbiturates and their pharmacology

Answer 11

activates barbiturate receptor and increases the duration of opening of chloride channel and can be long-acting (phenobarbital), short-acting (secobarbital) and ultrashort-acting (thiopental); have low TI, demonstrates a full spectrum of CNS depression, suppress REM sleep and suppresses respiratory and cardiovascular system

Question 12

Short-term effects of Barbiturates

Answer 12

tranquility, mild euphoria, relaxation,

Question 13

Long-term effects of Barbiturates

Answer 13

chronic inebriation, impairment of thinking, judgment, and memory, hostility and mood swings

Question 14

Abuse potential and dependence of Barbiturates

Answer 14

high abuse liability, high inherent harmfulness due to risk of death from respiratory depression and withdrawal, rapid tolerance to sleep and mood effects but slower for motor impairments, high dependence measured by severe withdrawal syndrome, addition occurs

Question 15

Gamma-hydroxybutyric acid (GHB)

Answer 15

antagonist to GABA receptors causing sedation and anesthesia; causes euphoria first and has been implicated as a date rape drug; not clinically used in North America

Question 16

Buspirone

Answer 16

acts on serotonin receptor instead of GABA and used in generalized anxiety states because it doesn’t have an additive effect with other sedative-hypnotics

Question 17

ADME of alcohol

Answer 17

A- rapidly absorbed from stomach and upper intestines
D- distributes all over body; readily gains access to brain and crosses placenta
M- converted to acetaldehyde (which produces unpleasant effects) by ADH, then to acetate by ALDH that is then broken down into CO2 and H2O
E- most eliminated by biotransformation in the liver and the rest excreted in breath, urine and sweat

Question 18

Pharmacology of Alcohol

Answer 18

CNS depressant that binds chloride channel and enhances GABA-mediated inhibition

Question 19

Short-term Effects of Alcohol

Answer 19

Lose dose: vasodilation of vessels to the skin, increased gastric secretion
high dose: arrhythmia, irritation of GI tract causing vomiting and ulcers, can inhibit glucose production, can lead to blackouts, impaired judgment, violence and respiratory depression

Question 20

Long-term Effects of Alcohol

Answer 20

mental disorders, cardiomyopathy, hypertension and stroke, fatty liver to hepatitis to cirrhosis

Question 21

Abuse potential and dependence of Alcohol

Answer 21

significant reinforcing properties and moderate dependence liability, tolerance can develop to chronic use, dependence and addiction occurs

Question 22

Cross-tolerance with alcohol

Answer 22

increased doses of sedative hypnotics and general anesthetics needed for someone with tolerance to alcohol (bc it can increase activity of metabolic enzymes in the liver)

Question 23

Alcohol Treatment

Answer 23

Disulfram- inhibits ADH so perceived adverse effects occur to deter user
Naltrexone- opioid antagonist that blocks activation of reward pathways
Acomprosate- ethanol susbtitute that acts as a GABA activator

Question 24

MOA and Administration of Cannabis (THC)

Answer 24

bind to CB1 receptors in the brain that inhibits the release of excitatory neurotransmitters; when inhaled the absorption is rapid and onset of action is immediate, after oral administration absorption is slow and incomplete with delayed onset of action; slowly metabolized

Question 25

Short-term effects of Cannabis

Answer 25

relaxation, drowsiness, euphoria, impaired motor coordination and judgment, pseudo-hallucinations, increased HR and blood flow to extremities, increased appetite and dry mouth, reduces sex drive and disruption of ovarian cycle

Question 26

Long-term effects of Cannabis

Answer 26

significant mental impairment can occur but disappears upon cessation, increase HR and bp that are reversible,, lung disease and lung cancers if smoked, decreased fertility and can cause defects in fetus

Question 27

Medical uses of Cannabis

Answer 27

prevention of nausea and vomiting associated with anti-cancers, increased appetite in anti-HIV drugs, neuropathic pain relief

Question 28

Abuse potential and dependence of Cannabis

Answer 28

dependence liability is low to moderate bc euphoria is less reinforcing, low inherent harmfulness, tolerance to psychoactive, cardiovascular effects and impairment of functions, dependence can occur w high doses, and addition can occur

Question 29

Narcotic Analgesics: Opioids and Opiates

Answer 29

opium comes from palaver somniferum, opiates are drugs derived from opium like codeine and morphine and opioids are any substances that exert actions on the body similar to those produced by morphine

Question 30

Opioid MOA

Answer 30

block pain pathways in the CNS through activation of primarily mu receptors (but also kappa and delta) that reduce presynaptic release transmitters from pain impulses, block their post-synaptic effect, activated inhibitory pathways to block pain input and reduce the emotional reaction to pain

Question 31

Short-term effects of Opioids

Answer 31

producing indifference to pain, sedation and hypnosis, suppression of cough centre, respiratory depression, reduces the release of sex hormones (reduced libido and menstrual irregularities), mioisis (pupil constriction), irregular HR, low body temp, constipation

Question 32

Long-term effects of Opioids

Answer 32

mood instability, pupillary constriction (impaired nigh vision), constipation, reduced libido, menstrual irregularity and respiratory impairment

Question 33

Therapeutic uses of Opioids

Answer 33

uses for morphine but not as much for heroin relief of severe pain, treatment of diarrhea, cough suppression

Question 34

Abuse potential and dependence of Opioids

Answer 34

high abuse potential, low inherent harmfulness for low doses but can be deadly in high doses bc respiratory suppression can lead to death, hazards with injecting, dependence and addiction develop to euphoric effects

Question 35

Opioid dependence treatment

Answer 35

oral methadone replaces opioid drug and dose is reduced slowly over time, the dose is not reduced but it substitutes it (risk-reduction bc availably orally), naxolone used to treat an overdose