3. CNS stimulants Flashcards
Three main categories of harm for CNS stimulants?
1. Physical harm – Acute vs chronic risks (e.g. nicotine) – Route of administration • (both primary and secondary risk) • Associated risks like needles and sharps injury, BBV transmission
- Dependence
– Intensity of pleasure (“rush”, “high”)
• Tolerance, craving, withdrawal
– Two types: Physical vs psychological dependence - Social harms
Name 2 Convulsants and Respiratory Stimulants
Doxapram
Strychnine
Doxapram, drug features?
Use?
Convulsants and Respiratory Stimulants
– short-acting respiratory stimulant used in respiratory failure, e.g.
• post-operative respiratory depression
• acute respiratory failure • neonatal apnoea
Strychnine: Class? Use? Effect? MoA?
Class: Convulsants and Respiratory Stimulants
Use:
Poison, convulsant
Small doses cause an improvement in visual and auditory acuity
Effect: violentextensorspasms triggered by minor sensory stimuli
MoA: blocks glycine receptors
Different classes of psychotomimetic drugs?
Hallucinogen
What is the action of hallucinogens?
Examples
Drugs that act on 5-HT receptors and transporters: – LSD (D-lysergic acid diethylamine) – Psilocybin (e.g. magic mushrooms) – Mescaline (e.g. from cacti) – MDMA (Ecstasy)
Where are the serotonin pathways in the brain?
Locus coeruleus
• (sensory signals)
Raphe nuclei
• (sleep, wakefulness and mood)
What is the raphe nuclei?
The raphe nuclei are a moderate-size cluster of nuclei found in the brain stem. Their main function is to release serotonin to the rest of the brain. Selective serotonin reuptake inhibitor (SSRI) antidepressants are believed to act in these nuclei, as well as at their targets.
What is the pharmacological Effects of Hallucinogens?
Main effects are on mental processes:
– alter perception of sights and sounds
– hallucinations (visual, auditory, tactile or olfactory) – sounds can be perceived as visions
– thought processes illogical and disconnected
Negative pharmacological effects of hallucinogens?
- ‘Bad trip‘
– hallucinations can take on a menacing quality – may be accompanied by paranoid delusions - ‘Flashbacks’
– can be reported weeks or months later
What is the tolerance issues of hallucinogens?
– develops quickly (plus cross-talk between drugs)
Dependence of hallucinogens?
There is no physical withdrawal syndrome
HOWEVER, Psychological effects (e.g. “flashbacks”, psychosis)
Name 4 associated risks when taking hallucinogens?
- Risk of injury and accidental death whilst intoxicated
- Poisoning due to mistaken identity
- Adrenergic effects with LSD (e.g. increase in symp so… increase in CVS parameters)
- GI effects with psilocybin
Name 2 dissociative anaesthetics?
Phencyclidine (PCP, Angel dust)
Ketamine
What is Phencyclidine (PCP, ‘Angel Dust’)?
Use
Dissociative anaesthetics
– synthesised as a possible i.v. general anaesthetic
– found to produce SIDE EFFECTS snd on recovering experienced disorientation and hallucinations
What is ketamine?
use
Dissociative anaesthetics
– used for induction and maintenance of anaesthesia