Overview of treating insomnia with medication
Adults sleep an average of seven to eight hours a day, but the need for sleep varies from person to person and usually diminishes with age. Insomnia is a very common condition, with a one-year incidence rate of 30%. It has three components which are sleep onset, sleep maintenance, and waking too early. When insomnia significantly impairs daytime functioning or well-being, then treatment options should be considered. Insomnia is particularly prevalent with mental health conditions such as anxiety, depression, dementia, bipolar affective disorder or ADHD. It is often triggered by a stressful event but the reasons for chronic insomnia are less understood. Chronic insomnia is rarely benefitted by hypnotics and can actually be caused by the injudicious use of hypnotics.
Physical causes like pain or substance misuse should always be ruled out before a hypnotic drug is prescribed.
Hypnotic drugs are normally licensed for short periods of time, usually two to four weeks. The exception is modified-release melatonin Circadin® which is licensed to treat insomnia in patients over 55 for up to 13 weeks. Melatonin is a hormone our body produces which regulates circadian rhythm and sleep function, and it has not been associated with tolerance or dependence. It has been used off-license for treating children and adolescents with insomnia.
Physical causes like pain or substance misuse should always be ruled out before a hypnotic drug is prescribed
Benzodiazepines and zolpidem, zaleplon or zopiclone (the ‘z-drugs’) are the most commonly prescribed hypnotics but they all may lead to dependence and tolerance after long-term use. As such, it is recommended that hypnotics are administered for no longer than seven consecutive days, preferably intermittently. Elderly patients are at an increased risk of ataxia, confusion and falls so benzodiazepines and z-drugs should be avoided or carefully monitored.
Insomnia can be a chronic condition and rebound insomnia may occur when a hypnotic is discontinued, so patients may find themselves on long-term hypnotic therapy due to the difficulties in stopping medication. In this situation, it is recommended to try intermittent hypnotic use, if possible, and to make regular withdrawal trials: say every three to six months depending on ongoing life circumstances and always with the patient’s consent. Cognitive Behaviour Therapy (CBT) during dose taper improves the outcome. Sedative antihistamines, like hydroxyzine or promethazine, are not addictive and are also popular hypnotics which could be used as alternatives. Nevertheless, their sedative effects usually wear off after continuous use.
NICE recommends prescribing the lowest-cost hypnotic, because of the lack of compelling evidence to choose between Z-drugs and benzodiazepines, but emphasises the need to stick to the product licences and prescribe them for short periods of time only. Furthermore, NICE recommends that switching between hypnotics should only occur if the patient suffers from adverse effects. NICE recommends that a patient who does not respond to the effects of one of these hypnotics should not be prescribed any of the others. However, clinicians find some patients do benefit from a switch, so this guidance may be discounted.
There are many non-pharmacological strategies for managing insomnia, such as ‘sleep hygiene’. The key points include: having a regular sleep routine in a comfortable space; the avoidance of sleeping during the day; the avoidance of caffeine, alcohol or nicotine before going to bed; eating dinner and exercising early; relaxing before sleep and going to bed to sleep only. If all these measures are followed, a hypnotic may not be required and the quality of sleep should usually improve.
For further information, see The Ashtons Formulary, which is accessible via Live View.