Chapter Ten - Psychomotor Stimulants

Question 1

Define:

Psychostimulants

Answer 1

• Common drugs of abuse, but many have legitimate therapeutic purposes.
• ie. cocaine, amphetamine.

Question 2

Provide Examples of 5 Common Psychostimulants:

Answer 2

1. Ampthetamine.
2. Cocaine.
3. Methylphenidate.
4. Cathinone.
5. Ephedrine.

Question 3

Khat and the Cathinones:

Answer 3

• Cathinones come from chewing leaves of tht knat plant.

Question 4

Cocaine:

Answer 4

• Comes from the coca bush in South America.
• Smoked, snorted, or injected.
• Never a slow drug.
• Has a much shorter half-life.
• Often taken in conjuction with other drugs.
• Quicket onset of withdrawal.
• Abuser’s can experience ‘coke-out’.

Question 5

Phases of Cocaine Overdose?

Answer 5

1. Initial excitement followed by severe headache, nausea, vomiting, and convulsions.
2. Loss of consciousness, respiratory depression, and cardiac failure causing death.

Question 6

Ephedrine & Amphetamine:

Answer 6

• Ma Huang has been used in traditional Chinese medicine for 5000 years, it is a natural soruce of ephedrine.
• Effective in treating asthma.
• Amphetamine is a cheaper substitute, and is used to treat Parkinson’s, sea sickness. It is a well known drug and addiction comes easily.

Question 7

Psychostimulant Administration:

Answer 7

• Taken many ways, which effects distribution and elimination.
• Readily absorbed and quickly distributed.
• They are smaller, so they can pass through barriers in the body quicker.

Question 8

Cathinone Absorption:

Answer 8

• Generally taken orally, absorbed in digestive system, & do not cross into the brain as well as others.

Question 9

Methamphetamines Absorption:

Answer 9

• Highest abuse liability with higher lipophilicity, quicker passage of the BBB, and greater stability against enzyme degradation.
• They like fatty tissues, hense faster way through BBB, and they are robust, meaning they can resist enzymes.

Question 10

Biggest Difference Between Meth & Cocaine?

Answer 10

• How it survives in the body.
• Meth will survive better and longer owing to its built in mechanism to avoid enzymes.

Question 11

What Enzymes Convert Methamphetamine into Amphetamine?

Answer 11

• Liver Enzymes.

Question 12

Psychostimulant Biotransformation Process?

Answer 12

• Occurs in the liver.
• Conversion into metabolites in order to be able to cross BBB.
• Drug combination may also interact to produce active metabolites.

Question 13

Psychostimulant Elimination:

Answer 13

• Amphetamine is metabolizes at low PH levels, so it does not want to leave, so you need to take bases to excrete it.
• Methamphetamine and cathinones are primarly broken down in liver.
• Cocaine has a short half-life [1 hour half-life].

Question 14

Monoamines?

Answer 14

• a compound having a single amine group in its molecule, especially one that is a neurotransmitter.
• Tyrosine hydrozylase is the most important one [capable to produce dopamine (chart shows L-Dopa)].

Question 15

Dopamine Receptors:

Answer 15

• Three inhbitory [D2-D4].
• 2 excitatory [D1 & D5].
• Are all metabotrophic.
• If a synapse was a grovrey store, these receptors are like the one cashier and there are a billion customers and the cashier is doing everything because there aren’t enough staff.

Question 16

Mesolimbic Dopaminergic ‘Reward’ Circuitry?

Answer 16

• Dopamine is associated with reward, motivation, & conditioning.
• Nucleus accumbens, medial forebrain bundle, substantia nigra, and ventral termental area [VTA].

Question 17

Norepinephrine Receptors:

Answer 17

• Four excitatory.
• One inhibitory, being A2.
• All metabotropic.

Question 18

Noradrenergic System:

Answer 18

• Norepinephrine has been associated with several brain functions, such as sleep, memory, learning, & emotions.
• The pathway of this system touches upon every other system in the brain [?].

Question 19

Serotonin Receptors:

Answer 19

• 2 inhibitory [5-HT1 & 5-HT5].
• 5 excitatory [2,3,4,6,7]
• Only 5-HT3 is ionotrophic, the rest are metabotrophic.
• 5-HT2 is seen a lot, most prominent

Question 20

Normal Transmission?

[Monoamines]

Answer 20

• Monoamines are released into the synaptic cleft and activates post synaptic receptors.
• Following the release and receptor-activation, neurotransmission is terminatied by the activity or specific enzymes in the cleft, and the reabsorption of neurotransmitter molesules into the presynaptic neuron.

Question 21

MOA of Cathinones:

Answer 21

• Cathinones have strong binding affinity for NETS and DATS.
• They do not touch sertoninergic signaling.
• Causes release of epinephrine, leading to fight or flight response.

Question 22

MOA of Amphetamines:

Answer 22

• Promiscuous in action and compete with molecules of monoamine for transport into the axon terminal via DATs, NETs, and SERTs.
• Capable of displacing monoamines from presynaptic neuron.
• Not just one mechanism, they have several.

Question 23

Define:

Unconditioned Behaviours

Answer 23

• Primates: behaviours vary grewatly between individuals, bu at high doses, automutlation is seen.
• Humans: formication may be seen.

Question 24

Define:

Physiological Effects

Answer 24

• Falls under objective effects.
• Things such as heart rate, blood pressure, body temp. increase, pupil dialation, vasodilation, etc.

Question 25

Harmful Effects of Psychostimulants?

Answer 25

• Cocaine: Liver damage. Injury to mucus membranes.
• Psychomotor stimulants: Blurred vision, paranoia, hallucinations, weightloss, attention issues.
• ADHD meds: lower growth due to suppressed appetite.

Question 26

Define:

The Neurotoxic Effect

Answer 26

• Abuse of amphetamines affects DA and 5-HT producing cells.
• Methamphetamine exposure can have long-term damage to DA and 5-HT cells within the hippocampus and prefrontal cortex.

Question 27

Effects of Tolerance?

Answer 27

• Appetite suppressing disappears after 2 weeks [ish].
• Increase in the lethal dosage.
• Stereotypes and psychotic behaviours increase.

Question 28

Define:

Detoxification

Answer 28

• Abstinence of drug.
• Relapse is common.

Question 29

Behavioural Therapies?

Answer 29

• Cognitive, contingency, and community reinforcements are commonly used.

Question 30

Pharmacotherapy Examples?

Answer 30

• Modafinil stimulates DA, norepinephrine, and glutamate.
• Methylphenidate can replace amphetamines.

Question 31

Define:

Ma Huang

Answer 31

• Traditional Chinese medicine for over 5000 years.
• The source of several natural psychostimulant compounds, such as ephedrine.

Question 32

Vin Miriani:

Answer 32

• A patented a coca-containing wine made by French chemist Angelo Mariani.

Question 33

The Harrison Act?

Answer 33

• Drove cocaine underground.
• 1914, banned the use of cocaine.

Question 34

Methylphenidate Half Life?

Answer 34

• Age dependent.
• Kids = 2.5 hours.
• Adults = 3.5 hours.

Question 35

Define:

Punding

Answer 35

• Stereotyped behaviour in humans, which are stimulus-induced behaviours.

Question 36

Name 4 Psychomotor Stimulants?

Answer 36

1. Amptheamine.
2. Methamphetamine.
3. Methcathinone.
4. Cocaine.

Question 37

Trends in the Annual Rates of Psychostimulant use in the US?

Answer 37

• Cocaine: Decrease, increase, decrease.
• Meth: slow increase, back to a slow decrease.
• Ampthetamine: gradual increase.

Question 38

Monoamine Psychosis?

Answer 38

• High doses and extended use of psychostimulants can result in psychosis, which is indistinguishable from schizophrenia.

Question 39

Modafinil?

Answer 39

• Stimulates dopamine, norepinephrine and glutamate neurotransmission.
• Limited abuse potential.

Question 40

Naltrexone?

Answer 40

• Opioid antagonists.
• Used in the treatment of alcohol dependence and a drug implant.