Exam 4: Psychomotor Stimulants, Inhalants, and Hallucinogens

Question 1

What are psychomotor stimulants classified as?

Answer 1

Schedule 2 drugs- meaning they have high potential for abuse but can be used for medical purposes. includes cocaine, methamphetamine, dexedrine, adderall, and ritalin.

Question 2

What do psychomotor stimulants do?

Answer 2

These are all sympathomimetic drugs meaning they cause sensorimotor activation which increase alertness, heightens arousal, and causes behavioral excitement. All stimulants stimulate catecholamine (NE, Dopamine, Epi) function and some serotonin function.

Question 3

What act prohibited the over the counter sale of cocaine?

Answer 3

The 1914 Harrison Narcotic Act

Question 4

What is the pharmacology of cocaine?

Answer 4

1. It is fat soluble so easily passes BBB
2. Half life is 0.5-1.5 hours
3. High lasts around 30 min

Question 5

What are the 3 NTs that cocaine acts on?

Answer 5

1. Dopamine- the euphoric.rewarding effects are related to the blocking of the dopamine reuptake transporter in the nucleus accumbens
2. Serotonin
3. Norepinephrine

Cocaine inhibits the reuptake of these NTs.

Question 6

How does cocaine effect the D1 Gs stimulatory receptor?

Answer 6

When cocaine blocks reuptake at D1 dopamine receptors, this is where we see the locomotor and rewarding effects of cocaine.

Question 7

How does cocaine affect the D3 Gi inhibitory receptor?

Answer 7

When cocaine blocks reuptake at the D3 dopamine receptor, this is where we also see the rewarding effect of cocaine.

Question 8

What are the acute effects of cocaine administration?

Answer 8

It is a sympathomimetic drug so it acutely produces symptoms related to sympathetic nervous system activation. Includes increased heart rate, vasoconstriction, hypertension, and hyperthermia.
Acute exposure can lead to sensitization that can last for a few weeks to a year in humans.

Question 9

What are the chronic effects of cocaine usage?

Answer 9

10-15% of recreational users become dependent. These individuals show abnormal prefrontal cortical functioning which manifests as deficits in inhibitory control.
Chronic exposure leads to tolerance which is typically seen in the euphoric effects in humans.

Question 10

Is there any FDA approved treatment for psychomotor stimulant dependence?

Answer 10

No. There is a contingency management program that can help. It is based on the premise that drug taking is an operant response that persists as a result of reinforcement. Even more effective when combined with the SSRI Citalopram.

Question 11

What are the majority of ampethamines classified as?

Answer 11

Schedule 2 drug. High potential for abuse with well known medicinal value.

Question 12

What are the two plants compounds that are similar to amphetamines?

Answer 12

1. Cathinone- active ingredient is khat. Mephedrone is a derivative of this and was sold as bath salts. Legal until 2011.
2. Ephedrine- from the herb Ephedra vulgaris. FDA banned sale of supplements with this compound in 2004 because it elevates BP and increases risk of heart attack and stroke.

Question 13

How were amphetamines initially used?

Answer 13

Used as anti-asthmatic first and then narcolepsy. Pilots took it in WWII to stay awake. After WWII, usage soared and peaked around 1970s.

Question 14

What is the pharmacology of amphetamines and methamphetamine?

Answer 14

1. They are metabolized by the liver at a slow rate.
2. Oral admin- 10-16 hour half life. High lasts 8 hours.

Question 15

What is the mechanism of action in which amphetamines exert their effects?

Answer 15

It acts like an indirect agonist of the catecholaminergic system.
1. It enters dopamine, NE, and serotonin nerve terminals via uptake by dopamine transporter, NET, or serotonin transporter and causes the vesicles to release more of that NT.
2. It reverses the reuptake transporters making dopamine, NE, and serotonin be pumped out instead of taken back up.
3. Some amphetamines inhibit the monoamine oxidase enzyme preventing breakdown of the NT.

Question 16

Amphetamines also have _____________ symptoms like what we see with cocaine.

Answer 16

Sympathomimetic. Lead to release of NE in brain and sympathetic nervous system.

Question 17

What are amphetamines used to treat?

Answer 17

It is used to treat attention deficits.

Question 18

Why do amphetamines help with ADHD?

Answer 18

In those with ADHD, there is abnormal functioning of the prefrontal cortex and possible hypofrontality. The neurons in the prefrontal cortex are innervated by noradrenergic and dopaminergic systems. By using these drugs and increasing the concentration of NTs, we can improve symptoms of ADHD.

Question 19

What are the consequences of chronic methamphetamine usage?

Answer 19

1. It damages dopamine axons and terminals.
2. It damages serotonergic fibers in neocortex, hippocampus, and striatum
3. Associated with cardiovascular problems like elevated BP, and leads to increased risk for heart attack, stroke, and atherosclerosis.
4. Can cause amphetamine psychosis where there are hallucinations, paranoia, behavioral disorganization, and more.

Question 20

What are hallucinogens?

Answer 20

These are substances that alter sensory processing in the brain causing perceptual disturbances, changes in thought processing, and depersonalization.

Question 21

What are the drugs that are under the LSD class?

Answer 21

1. LSD- lysergic acid diethyl amid. (3-5 hr 1/2 life)
2. Mescaline- peyote. (6 hr 1/2 life)
3. Psilocybin- mushrooms (2.5 hrs 1/ life)
4. N,N-Dimethyltryptamine- DMT

Question 22

What is the MOA of LSD class of drugs?

Answer 22

They act as agonist of the 5-HT2A serotonin receptors. This distorts the sorting process. Also acts on raphe nucleus which functions to filter incoming sensory stimuli.

Question 23

What are the drugs within the dissociative drug class?

Answer 23

1. PCP- phencyclidine (synthetic with 1/2 life 7-45 hours)
2. Ketamine- 1/2 life of 2-3 hr
3. Dextromethorphan- weak opiate agonist (1/2 life 2-3 hr)

Question 24

What is the MOA for the dissociative drug class?

Answer 24

These drug inhibit NMDA-type glutamate receptors.

Question 25

What are the effects of dissociative drug use?

Answer 25

Experience feelings of power, strength, invulnerability. Perceptual distortions, paranoia, violence, and potential for psychotic break. Also has hallucinogenic effects.

Question 26

What are inhalants?

Answer 26

Commonly abused inhalants include everyday household items that are volatile liquids or gas at room temperature. Includes things like adhesives, inks, paint thinners, dry-cleaning fluid, gasoline, and more.

Question 27

What are aerosols?

Answer 27

These are sprays that contain various solvents and propellants such as hair sprays, deodorant sprays, oil sprays and more.

Question 28

What are gases?

Answer 28

Gases include things like nitrous oxide in whipped cream cans, propane tanks, butane lighters, and more.

Question 29

What are nitrites?

Answer 29

Nitrites are typically used to heighten sexual arousal and pleasure. They work by dilating blood vessels and causing muscle relaxation.

Question 30

What group most commonly uses inhalants?

Answer 30

Children and adolscents

Question 31

What are the acute effects of inhalant use?

Answer 31

Similar to alcohol intoxication. Feelings of euphoria, stimulation and disinhibition, followed by drowsiness and lightheadedness.

Greater exposure causes stronger depressant effect like slurred speech, poor coordination, ataxia, lethargy.

Very high doses can lead to anesthesia, loss of consciousness, and coma.

Question 32

Do most inhalant users become dependent?

Answer 32

No. However some can. There is evidence of withdrawal symptoms in those who abuse frequently.

Question 33

What is Toluene?

Answer 33

This is clear and colorless liquid that becomes vapor when exposed to room temperature air. It has a sharp and sweet odor.
Two studies found that toluene activated the dopamine neurons in the ventral tegmental area when inhaled or directly applied in vitro.

However, the neural mechanisms underlying the reward and reinforcement of inhalants is not well known.

Question 34

How are inhalants absorbed?

Answer 34

They are rapidly absorbed from the lungs and quickly enter the brain de to high lipid solubility.

Question 35

What is the main MOA of inhalants even though we are not 100% sure if it is correct?

Answer 35

Inhalants are CNS depressants. They enhance the function of inhibitory GABA A receptors and inhibit activity of excitatory NMDA glutamate and nicotinic cholinergic receptors.

Question 36

What are the effects of chronic inhalant use?

Answer 36

The brain concentrates inhalants in white matter due to lipid content and its solubility. Chronic use is associated with white matter degeneration (damage to myelin sheath), cerebellar dysfunction, and damage to cranial and peripheral nerves.

Question 37

What is fetal solvent syndrome?

Answer 37

Fetuses exposed to inhalants have similar abnormalities seen in children of women with alcohol use disorder during pregnancy. They are often premature and low birthweight.

Question 38

Which serotonin receptor is responsible for the hallucinogenic effects of LSD?

Answer 38

5-HT2A

Question 39

Nicotine addiction is often co-morbid with what other condition?

Answer 39

Schizophrenia

Question 40

What hallucinogenic substance is found in hallucinogenic mushrooms?

Answer 40

Psilocybin

Question 41

Which hallucinogenic/dissociative drug has been shown to shrink the brain after long-term use?

Answer 41

Toluene

Question 42

Which abused drug is FDA approved to treat attention-deficit disorders?

Answer 42

Methamphetamine

Question 43

Which medication is both a dissociative drug and an FDA approved drug?

Answer 43

Ketamine

Question 44

Psychoactive bath salts are derived from plants?

Answer 44

Evergreen Shrub

Question 45

What is the most commonly abused psychomotor stimulant?

Answer 45

Cocaine

Question 46

Which brain image is that of a methamphetamine user?

Answer 46

The right image