CNS stimulants

Question 1

What are the 3 categories of harm?

Answer 1

• Physical harm
• Dependence
• Social harm

Question 2

What is physical harm?

Answer 2

• Can be acute (e.g. in those with asthma) or chronic (e.g. cancer)
• Harm due to route of administration:
- primary i.e. overdose
- secondary risk i.e. introducing infection

Question 3

What is social harm?

Answer 3

• Drinking and driving
• Drug culture
• Illegal trade e.g. trafficking

Question 4

Describe the classifications of drugs in the UK misuse of drugs act

Answer 4

• class A - most dangerous, carries the harshest punishments
• class B
• Class C - deemed to have the least capacity for harm, more lenient punishment

Question 5

What are the types of CNS stimulants?

Answer 5

• Convulsants and respiratory stimulants
• Psychotomimetic drugs
• Psychomotor stimulants

Question 6

Give two examples of convulsants and respiratory stimulants

Answer 6

• Doxapram

* Stychnine

Question 7

Doxapram

Answer 7

• Used in respiratory failure (short acting respiratory stimulant)
- post operative respiratory depression
- acute respiratory failure
- neonatal apnoea
• Stimulates chemoreceptors in the carotid bodies in carotid arteries -> respiratory centre

Question 8

Strychnine

Answer 8

• Used for centuries as a poison
• Powerufl convulsant
• Violent extensor spasms triggered by minor sensory stimuli
• Blocks glycine receptors associated with motor control
• Small doses cause an improvement in visual and auditory acuity

Question 9

What are psychomimetic drugs?

Answer 9

• Hallucinogneics

* Drugs that act on the 5-HT receptors and transporters

Question 10

Serotonin pathways in the Brain

Answer 10

• Locus coeruleus - sensory signals

* Raphe nuclei - sleep wakefulness, mood

Question 11

What are the pharmacological effects of hallucinogenics?

Answer 11

• Main effects are on mental processes
- altered perceptions of sight and sound
- hallucinations
- sounds can be perceived as visions
- thought processes illogical and disconnected
• Bad trip
• Flashbacks can be reported weeks or months later

Question 12

Bad trip - hallucinogenics

Answer 12

• Hallucinations can take on a menacing quality

* May be accompanied by paranoid delusions

Question 13

Tolerance of hallucinogenics

Answer 13

• Develops quickly

* Cross talk between drugs

Question 14

Withdrawal of hallucinogenics

Answer 14

• No physical withdrawal syndrome

* Psychological effects (flashbacks, psychosis (rare))

Question 15

What are the risks of hallucinogenics?

Answer 15

• Risks of injury and accidental death while intoxicated
• poisoning due to mistaken identity
• Adrenergic effects with LSD
• GI effects with psilocybin

Question 16

Name two dissociative anaesthetics

Answer 16

• Phencyclidine (PCP, angel dust)

* Ketamine

Question 17

Effects of dissociative anaesthetics

Answer 17

• Analgesic
• Stereotyped motor behaviour
• Can give a bad trip as LSD can
• NMDA antagonist

Question 18

tolerance for dissociative anaesthetics

Answer 18

• Rapid over regular repeated doses

Question 19

Dependence dissociative anaesthetics

Answer 19

• Physical and psychological dependence

* Withdrawal syndromes with PCP

Question 20

What are the risks of dissociative anaesthetics?

Answer 20

• Accidents/loss of control
• PCP: hyperthermia, convulsions
• Ketamine: overdose with heart attack/respiratory failure

Question 21

Name 3 psychomotor stimulants

Answer 21

• Amphetamine
• Dextroamphetamine
• Methylamphetamine

Question 22

What are the main effects of psychomotor stimulants?

Answer 22

• Locomotor stimulation
• Euphoria and excitement
• Insomnia
• Anorexia
• Sterotypic behaviour