n_insomnia
Table of Contents
insomnia
see also:
Introduction:
- see physiology of sleep for details on control of sleep, sleep requirements, etc.
- consequences of acute sleep deprivation include:
- impaired passive vigilance
- impaired reaction time
- impaired hand-eye coordination - ever tried playing a musical instrument or even golf after little sleep?
- impaired clerical accuracy
- impaired memory
- impaired reasoning
- increased sleepiness and micro-sleep events (eg. when driving a car)
- increased risk of car accident and other accidents
- consequences of slow wave (delta wave) sleep deprivation include:
- impaired cognitive performance
- impaired immunity and ability to recuperate
- consequences of REM sleep deprivation include:
- moodiness and risk of both depression and hypomanic states
- hypersensitivity to stimuli (and perhaps lowering of the migrain threshold)
- inability to consolidate complex learning
- consequences of long term sleep deprivation include:
- decreased longevity in animal models
- depression
- burnout
- divorce
- substance abuse
- chronic hypertension
- metabolic syndrome, obesity and diabetes mellitus
- increased cardiovascular mortality equivalent to more than 1 packet/day of cigarettes
- infertility
- injury risk
- sleep debt:
- sleep latency can be measured
- very poor correlation between self-reported sleepiness and objective measures of fatigue
- alcohol intake causes sleep fragmentation and decreased REM sleep - hence one feels tired the next day
- most sedative-hypnotics disrupt sleep architecture and are associated with impaired quality of sleep
-
- 250mg improves psychomotor performance if sleep deprived but 500mg gives no further improvement but adds side effects
- brewed coffee has ~135mg, while tea has 35-50mg.
- benefit subject to tachyphylaxis
- constant high doses may cause withdrawal headaches
- adversely effects sleep latency and sleep quality
- micro-awakenings decrease time in slow wave sleep and decrease time in REM sleep
- a regular siesta may reduce coronary mortality by 37% 1)
- the only way to reverse the need for sleep is to sleep
- insomnia or difficulty in getting to sleep is a symptom and thus a cause should be sought
Aetiology:
psychiatric factors:
- emotional stress/anxiety - tends to cause trouble with falling asleep
- depression - tends to cause sleep which is interrupted by frequent awakenings
environmental factors:
- bedroom too hot, too cold, too noisy (eg. crying baby, restless child, partner with snoring)
- bed cramped or uncomfortable
physical factors:
- obstructive sleep apnoea
- chronic airways limitation
- acute illness such as URTI, asthma, or pain
disturbed sleep cycles:
- delayed sleep phase disorder
- the main cause in perhaps 15% of people with insomnia
- hard to get to sleep before 2am and hard to wake up early
- may respond to metatonon or agomelatine (Valdoxan), a new antidepressant which also acts on melatonin receptors to cause a phase advance.
- poor sleep hygiene
- lack of daytime exercise
- inadequate daytime exposure to light
- excessive time in bed
- jet lag
Clinical approach:
- consider pt maintaining a sleep log to help ascertain extent & type of disturbance
- managing insomnia in older people:
- discuss & agree on therapeutic objectives with the patient
- assess the complaint - what is causing it?
- treat or improve the underlying cause
- educate the patient about good sleep habits - see behavioural Rx below
- avoid use of hypnotic drugs whenever possible as adverse effects usually outweigh benefits except perhaps in short term usage, when prescriptions should be only for 2 weeks maximum
- for every 13 patients aged over 60 years treated with hypnotics, it will improve sleep in 1 person but will cause an adverse effect (cognitive impairment, falls. fractures, motor vehicle accidents) in 2 people
behavioural Rx of insomnia:
- see sleep hygiene to ensure lifestyle maximises probability of quality sleep
- consider anxiety management & relaxation techniques if pts worried & anxious they will not be able to get to sleep
- consider cognitive behavioural therapy techniques
- replace distorted beliefs and attitudes with positive ones
- reassure that less than 8 hours sleep per night is not necessarily detrimental
- address learned association between going to bed and being unable to sleep
- go to bed only when tired, and only use bed for sex or sleep
- get out of bed if not asleep within a perceived 20 minutes - but DO NOT watch the clock
- repeat each night until a stable sleep-wake schedule is established
- restrict sleep time in bed to actual sleep duration (but at least 5 hours sleep) and have a set wake up time
drug Rx of insomnia:
- if hypnotics must be used, use them only 2-5 times per week and for less than 2 weeks duration
-
- long half-life benzodiazepines (esp. in elderly) result in increased risk of:
- confusion, drowsiness, memory loss, unsteadiness, falls (thus hip fractures) & incontinence
- doubles risk of road traffic accidents in all age groups, but in addition, in persons over 65yrs, have an additional 50% risk if brief duration Rx or 30% risk if long term Rx.
- most benzodiazepines lose their hypnotic efficacy after approx. 14 consecutive nights, even though people still keep taking them
- quality of sleep is modified - less deep & relaxed sleep; tendency to fall asleep & awake earlier;
- day-time: feelings of tiredness; lack of energy; mood disturbances;
- the 'Z drugs':
- act on same receptor as benzodiazepines
- said to have less adverse effects & less dependency than benzodiazepines, but these are still present
- zolpidem has caused delirium, hallucinations, nightmares & hip fractures (2x risk of no Rx & more than Rx with benzo's, anti-psychotics or antidepressants)
- zopiclone:
- causes hangover effects & impairs psychomotor performance similar to temazepam & nitrazepam
- has bitter taste
- zaleplon:
- short half-life, thus useful for sleep-onset insomnia
- valerian:
- herbal extract with mild hypnotic activity, but limited studies as yet.
- melatonin:
- a naturally occurring hormone secreted from pineal gland
- widely used to regulate sleep-awake cycles in circadian-based disorders such as jet lag
- adverse effects: enhanced immune functioning, vasoconstriction, exacerbation depression
-
- should not be used to Rx insomnia unless concurrent depression
-
- should not be used as cause anticholinergic effects & confusion, esp. in children & elderly & tolerance develops quickly
ceasing hypnotic medications
- prolonged Rx with hypnotic medications for > 4 weeks increases risk of dependence
- this is particularly a problem with the elderly who are most at risk of adverse effects such as increased falls
- rebound insomnia may occur even with short term hypnotic use of less than 2 weeks and thus gradual dose reduction may be needed
step 1 - raise awareness of the need to stop
- provision of a letter advising cessation combined with self-help advice doubles the chances of a patient wishing to cease Rx
step 2 - STOP guide to reducing hypnotic Rx
- see NPS 2)
Share views and agree on a stopping plan
- discuss goals for stopping or reducing use
- agree on rate and duration of cessation
- outline the type, nature and expected duration of withdrawal symptoms
- advise on strategies to Mx withdrawal symptoms
Taper dosage gradually
- modify dose and/or frequency based on severity of withdrawal symptoms
- all time to stabilise between dosage reductions - at least a few days
- consider referral to a specialist if dose reduction proves too difficult
- example reduction of benzodiazepines:
- reduce dose by 10-20% per week if it is within or slightly above the recommended dose
- stabilise on an equivalent dose of diazepam (unless elderly) for a few days before dose reduction if patient was on a higher than recommended dose or finding it difficuklt to wean a short-acting agent.
- if multiple benzodiazepines are used, the dose of each drug may be reduced one after the other
Ongoing review
- weekly monitor effect of cessation on sleep patterns, mood, withdrawal symptoms and use of other substances (eg. alcohol, caffeine)
- encourage use of non-drug therapies
- suggest coping strategies
Provide support and reassurance
- engage family, carers, staff in residential facilities
- if unsuccessful, reassure that further attempts are worthwhile
- repeat STOP steps when patient willing to try again
n_insomnia.txt · Last modified: 2013/08/24 01:20 by 127.0.0.1