Because most medications usually require 6–8 hours of sleep to avoid lingering effects the next day, these are often used every night at bedtime to prevent awakenings. Medication may not be prescribed in some cases, especially if the cause turns out to be the patient ingesting too much fluid during the day or just before they go to sleep. Sleep restriction therapy and stimulus control therapy as described in insomnia have shown significance in treating middle of night insomnia. Some studies have shown that zaleplon, which has a short elimination half-life, may be suitable for middle-of-the-night administration because it does not impair next day performance. Prevalence
Waking up in the middle of the night, or nocturnal awakening, is the most frequently reported insomnia symptom, with approximately 35% of Americans over 18 reporting waking up three or more times per week. Of those who experience nocturnal awakenings, 43% report difficulty in resuming sleep after waking, while over 90% report the condition persisting for more than six months. Greater than 50% contend with MOTN conditions for more than five years. A 2008 "Sleep in America" poll conducted by the National Sleep Foundation found that 42% of respondents awakened during the night at least a few nights a week, and 29% said they woke up too early and couldn’t get back to sleep. Other clinical studies have reported between 25% and 35% of people experience nocturnal awakenings at least three nights a week. See also
Biphasic and polyphasic sleep


== References ==
The norpethidine metabolite was found to have serotonergic effects, so pethidine could, unlike most opioids, contribute to serotonin syndrome. Medical uses
Pethidine is the most widely used opioid in labour and delivery but has fallen out of favour in some countries such as the United States in favour of other opioids, due to its potential drug interactions (especially with serotonergics) and its neurotoxic metabolite, norpethidine. It is still commonly used in the United Kingdom and New Zealand, and was the preferred opioid in the United Kingdom for use during labour, but has been superseded somewhat by diamorphine and other strong semi-synthetic opioids (e.g. hydromorphone) to avoid serotonin interactions since the mid-2000s. Pethidine is the preferred painkiller for diverticulitis, because it decreases intestinal intraluminal pressure.Before 2003 it was on the World Health Organizations List of Essential Medicines, the most effective and safe medicines needed in a health system. Adverse effects
The adverse effects of pethidine administration are primarily those of the opioids as a class: nausea, vomiting, dizziness, diaphoresis, urinary retention, and constipation. Due to moderate stimulant effects mediated by dopamine and norepinephrine, sedation is less likely compared to other opioids. Unlike other opioids, it does not cause miosis because of its anticholinergic properties. Overdose can cause muscle flaccidity, respiratory depression, obtundation, psychosis, cold and clammy skin, hypotension, and coma. A narcotic antagonist such as naloxone is indicated to reverse respiratory depression and other effects of pethidine.