CNS Stimulants

Question 1

Psychomotor stimulants

Answer 1

Amphetamines and related drugs

Methylxanthines

Nicotine

Question 2

Psychotimimetic Agents (Hallucinogens)

Answer 2

Cannabinoids

Ketamine

Question 3

Psychomotor stimulants have a marked effect on mental function and behavior such as:

Answer 3

Produce excitement and euphoria

Reduce sensation of fatigue

Increase in motor activity

Question 4

Amphetamines include:

Answer 4

amphetamine

dextroamphetamine

methylphenidate

dexmethylphenidate

Question 5

MOA of psychomotor stimulants:

Answer 5

Acts by releasing monoamines, primarily NE and DA from intracellular vesicular storage sites

Block or reverse the direction of transporters that mediate the reuptake of NE, DA, 5-HT

Act on LOCUS CERULEUS NEURONS IN THE PONS:

• ASCEND adrenergic projections throughout HYPOTHALAMUS+THALAMUS, Cerebral cortex, spinal cord
• DESCEND adrenergic projections to the medulla and spinal cord

Act on midbrain DA neurons associated with the reward pathway

Question 6

With long term use, amphetamines are neurotoxic and can lead to ________ of amine-containing nerve terminals and eventually _______ can occur.

Answer 6

With long term use, amphetamines are neurotoxic and can lead to DEGENERATION of amine-containing nerve terminals and eventually CELL DEATH can occur.

Question 7

Due to a combined action of NE and DA, amphetamine stimulates the entire cerebrospinal axis, cortex, brain stem and medulla leading to:

Answer 7

Increased alertness

Decreased fatigue

Depressed appetite

Insomnia

Locomotor stimulation

Question 8

Tolerance and Dependence of Amphetamines:

Answer 8

RAPID tolerance and dependence to EUPHORIC and ANOREXIC actions

SLOW tolerance and dependence to LOCOMOTOR STIMULATION

No w/d symptoms compared to opioids

Question 9

Methylphenidate acts by:

Answer 9

blocking DA and NE transporters leading to increase concentrations of amines in synaptic space.

Question 10

MOA of methylxanthines:

Answer 10

Inhibition of phosphodiesterase leading to increases in cellular cyclic AMP and cyclic GMP concentrations.

Blockade of presynaptic adenosine receptors on dopaminergic and adrenergic terminals.

Blockade of adenosine receptors on cortical neurons.

Question 11

Caffeine is used in combination with other drugs for the

treatment of the following disorders:

Answer 11

Musculoskeletal Disorders: Caffeine plus aspirin

Dysmenorrhea: Caffeine plus acetaminophen plus pyrilamine

Migraine and headache: Caffeine plus butalbital plus codeine;
Caffeine plus ergotamine or dihydroergotamine

Pain Management: Caffeine plus dihydrocodeine; caffeine plus
acetaminophen plus dihydrocodeine; caffeine plus aspirin
plus acetaminophen

Question 12

Nicotine MOA

Answer 12

Nicotine activates nicotinic ACh receptors that are located centrally, peripherally and at the neuromuscular junction.

Cholinergic neurons leaving the laterodorsal tegmental area
(near the border of the midbrain and pons) activate muscarinic
and nicotinic receptors on dopaminergic neurons in the
ventral tegmental area.

Activation of the nicotinic receptors stimulates the dopaminergic reward system.

Question 13

TorF: Activation of presynaptic nicotinic receptors on dopaminergic
terminal facilitates the release of dopamine

Answer 13

True

Question 14

TorF: High doses of nicotine produce weak analgesia and low doses causes tremors leading to convulsions.

Answer 14

False Low doses produce weak analgesia; high doses causes

tremors leading to convulsions.

Question 15

Pharmacological actions of nicotine on the CNS:

Answer 15

Stimulant action on respiration:

Large doses via a direct action the medulla

Small doses via an indirect action by reflex stimulation of chemoreceptors in the carotid and aortic bodies

Induces vomiting by both central and peripheral actions

Question 16

Central:

Answer 16

Central: due to stimulation of the chemoreceptor trigger

zone in the area postrema of the medulla oblongata

Question 17

Peripheral:

Answer 17

due to activation of vagal and spinal afferent nerves that form part of the sensory input of reflex pathways involved in the act of vomiting.

Question 18

Nicotine action of PNS

Answer 18

Transient stimulation followed by a more persistent
depression of all autonomic ganglia

Low doses stimulate ganglion cells directly and may facilitate impulse transmission.

High doses cause initial stimulation which is followed quickly by blockade of transmission.

Question 19

Effect of Nicotine on CVS

Answer 19

Increase in blood pressure and heart rate:

Due to stimulation of the sympathetic ganglia and
adrenal medulla

Nicotine-induced vasoconstriction can decrease coronary
blood flow.

Question 20

Psychotomimetics or hallucinogens mainly affect:

Answer 20

Thought patterns and perception: tends to become distorted and dream-like (rather than being sharpened or dulled).

Mood: produce changes in mood that is more complex
than a simple shift in the direction of euphoria or depression.

Question 21

TorF: Psychotomimetic agents do not cause dependence

Answer 21

True. Psychotomimetic agents do not cause dependence even
though the psychological actions overlap those of the highly addictive psychostimulants (such as cocaine and amphetamines).

Question 22

Cannabinoids MOA:

Answer 22

Act on G protein-coupled receptors:.
 CB1-receptors are mainly found in the CNS
 CB2-receptors are found in the periphery

CB1-receptors are localized presynaptically where
they inhibit neurotransmitter release. They are concentrated in the hippocampus, cerebellum, hypothalamus, substantia nigra and prefrontal cortex.

CB2-receptors are located mainly in lymphoid tissue (spleen,
tonsils, thymus and circulating lymphocytes and tissue mast cells) and microglia-immune cells of the CNS.

Question 23

Endogenous ligands for CB receptors are known as

endocannabinoids:

Answer 23

Anandamide

2-arachidonoyl glycerol (2-AG)

Question 24

The pharmacological effects of THC varies with:

Answer 24

 Dose
 Route of administration
 Experience of the user
 Vulnerability to psychoactive effects
 Setting of use

Question 25

Tolerance to cannabinoids is due to:

Answer 25

down-regulation of CB1-receptors and post translational modifications that reduce signal transduction efficiency.

Question 26

Blockade of CB1-receptors with_______ can precipitate a

withdrawal system in chronic users.

Answer 26

Blockade of CB1-receptors with rimonabant can precipitate a

withdrawal system in chronic users.

Question 27

TorF: Dronabinol is a natural cannabinoid

Answer 27

False: synthetic

Question 28

Dronabinol is used:

Answer 28

As refractory nausea and vomiting associated with cancer chemotherapy

Anorexia/cachexia

Question 29

Ketamine acts by __________ receptor channels

Answer 29

Act by blocking glutamate-activated NMDA receptor channels.

Question 30

Ketamine uses:

Answer 30

Used as sole anesthetic agent for diagnostic and surgical procedures not requiring skeletal muscle relaxation

Induction prior to other general anesthesia

Supplement to low-potency agents (e.g., nitrous oxide)