Insomnia (DONE) Flashcards
Sedation and the induction of sleep
Sleep occurs in several levels (on the basis of CNS activity)
25% REM sleep, associated with dreaming
75% Non-REM sleep i.e. slow wave sleep, deepest level of sleep, stages 1-4
The biology of sleep-GABA
Neurons in the ventro-lateral pre-optic nucleus (VLPO) of the hypothalamus are GABA sensitive
Switching on the neurons in the VLPO may initiate sleep, by inhibiting midbrain areas that control wakefulness
The neurotransmitters involved are GABA, but also histamine, NA and 5-HT
Insomnia
Reflects a disturbance of arousal and/or sleep systems in the brain
Can be caused by any factor which increases activity in arousal systems or decreases activity in sleep systems
Effects of sleep deprivation
Risk of type 2 diabetes Impaired immune system Increased heart rate variability and risk of heart disease Increased reaction time Decreased accuracy, tremors and aches Growth suppression Risk of obesity Decreased temperature
Causes of insomnia (drug related)
Recreational drugs- caffeine, nicotine, alcohol, cannabis
Medicinal drugs- anticonvulsants, antipsychotics, beta blockers, SSRIs, MAOI, steroids, decongestants, alpha agonists and antagonists, narcotic analgesics
Drug withdrawal- CNS depressants e.g. alcohol, anxiolytics/hypnotics
Cause of insomnia (not drug related)
Physiological- diet, late night exercise, shift work (night and evening work)
Environmental- noise, bright lights, extremes of temperature
Medical conditions- anxiety, depression, grief, stress, chronic pain, gastric reflux, asthma. sleep apnoea
Types of insomnia
Primary insomnia- not attributable to a medical, psychiatric or environmental cause
Secondary insomnia- secondary to another condition
Transient (2-3 days): caused by changes in routine
Short term (<3 weeks) temporary environment stress
Chronic (>3 weeks): usually secondary to other conditions
Treatment for insomnia
Non-drug treatment e.g. lifestyle changes, CBT
Hypnotics: BZDs, BZD-like dugs, melatonin
Before a hypnotic is prescribed the cause of the insomnia should be established and, where possible, underlying factors should be treated
NICE guidelines for treatment
Doctors should consider using non-medicine treatments
Then, if they think that a hypnotic medicine is the appropriate way to treat severe insomnia that is interfering with normal daily life, they should prescribe one for only short periods of time and strictly according to the license for the drug
Good sleep hygiene
Establishing fixed times for going to bed and waking up
Trying to relax before going to bed
Maintaining a comfortable sleeping environment
Avoid napping during the day
Avoid caffeine, nicotine and alcohol late at night
Avoid eating a heavy meal late at night
Using the bedroom mainly for sleep if possible
Benzodiazepines
Most decrease the time taken to get to sleep, and in individuals who habitually sleep < 6hr, then increase the duration of sleep
A few short acting BDZs recommended for insomnia (short term treatment, max 2-4 weeks)
Should be used only when it is severe, disabling, or causing the patient extreme distress
BDZ like drugs
Z-hypnotics- zaleplon, zopiclone, zolpidem
Short term use
Lack anxiolytic effects
Bind to GABAa in a similar manner to BZDs but bind preferentially to a1 subtype
Zopiclone
Hypnotic effects similar to BZDs and similar potential for adverse effects including tolerance, dependence and withdrawal effects
Psychiatric reactions including hallucinations and nightmares have been reported shortly after first dose
No CD regs, may cause less alteration of sleep stages
More expensive than BDZs
Melatonin and the biological clock
Hormone produced by the pineal gland, which regulates the circadian rhythm of sleep
Released once it becomes dark, continues until first light of day
Melatonin as a treatment
Decreases with age
Melatonin promotes sleep initiation and resets circadian clock
Prolonged release melatonin available for primary insomnia in over 55 year olds
