CPTP 3.5 Neuropharmacology 3 (Hypnotics and Anxiolytics) Flashcards
(45 cards)
What are the stages of sleep?
First 3 hours –> ‘slow wave’ sleep
After that –> REM sleep
What happens during each stage of sleep, and what brain region is responsible for the activity?
Slow wave sleep:
• Hippocampus and neocortex
• Reactivation of memories from the day
REM sleep:
• Cortex
• Consolidation of memory into long-term stores
Recall the mechanisms of arousal
- Suprachiasmatic nucleus receives messages from the retina
- This activates the dorsomedial hypothalamic nucleus
- This activates the arousal pathways
Recall the ascending arousal pathways (which are activated by the dorsomedial hypothalamic nucleus)
What do they all do?
- Raphe nucleus (5-HT)
- Locus coeruleus (noradrenaline)
- Tuberomammillary nucleus (histamine)
These project to the cortex and keep it alert by “washing over” the synapses
What structures inhibit the ascending arousal pathways?
Ventrolateral preoptic nucleus • GABA • Galanine Pineal gland • Melatonin
What are the arousal and sleep-inducing neurotransmitters?
Sleep inducing: • GABA • Galanine • Melatonin Arousal: • Histamine • Noradrenaline • Serotonin
What happens to sleep as you age? Why?
Much reduced duration of sleep. You produce less melatonin as you age
What are the types of insomnia?
- Initial (cant get to sleep)
- Middle (wake up in the middle of the night)
- Early waking
What are the causes of insomnia?
>Stress >Psychiatric disorders: • Anxiety • Depression • Bipolar • PTSD >Illness • Alzheimers • Rheumatoid arthritis • Asthma >Medication • Stimulants • Antidepressants
Why does stress cause insomnia?
Increased HPA axis activity causes arousal pathways to be more active
What cause of insomnia gives rise to:
1) initial insomnia?
2) terminal insomnia?
1) Anxiety
2) Depression
What effect do bipolar disorder and PTSD have on sleep?
Bipolar disorder:
• Less SWS
PTSD:
• Less REM
What properties must a hypnotic have?
- Short half-life
- Inhibits ascending arousal pathways
- Does not affect REM or SWS brain areas
What physiological effect does anxiety have?
Sympathetic NS activation: • CV • Hyperventilation • Sweating • GI (butterflies)
What ‘theme’ of core symptoms fo anxiety disorders share?
Fear, escape, avoidance
Name the anxiety disorders
- OCD
- PTSD
- GAD
- Panic disorder
- Agoraphobia
- Social anxiety
What three main neurotransmitters are associated with anxiety disorders?
Serotonin and noradrenaline - Increased
• Increased release
GABA - Decreased
• Decreased amounts of GABA-A receptor function, so less binding
What effect do SSRIs have on 5-HT levels and anxiety?
Increases 5-HT in synaptic cleft, and increases anxiety
How are hypnotics and anxiolytics linked?
They both are non-specific CNS depressants that reduce levels of arousal, the difference is the dose.
(To induce sleep, a higher dose is needed than for anxiolytic effects.)
How should hypnotics and anxiolytics half lives differ?
Anxiolytics - Long half life
Hypnotics - Short half life
What are the classes of hypnotics and anxiolytics? What separates these?
- Barbituates
- Benzodiazapines
- (Alcohol)
HYPNOTIC ONLY:
• Z-hypnotics
• Antihistamines
Therapeutic windows and pharmacokinetics
Why are barbituates not used any more?
- Interact with alcohol
* Very small therapeutic window
Name the formulary benzodiazepines. What is the half-life and use of each?
Name the formulary Z-hypnotic
- Temazepam, 10hrs, hypnotic
- Lorazepam, 15 hrs, anxiolytic
- Chlorodiazepoxide, 20hrs, anxiolytic
- Diazepam, 40hrs, anxiolytic
Z-hypnotic:
• Zopiclone, 6 hours
What other use can hypnotics and anxiolytics have?
- Reduce muscle tone (i.e. in tension headaches)
- Anticonvulsant
- Surgical sedative