|
Hypnotic (from Greek ''Hypnos'', sleep) or soporific drugs, commonly known as sleeping pills, are a class of psychoactive drugs whose primary function is to induce sleep and to be used in the treatment of insomnia (sleeplessness), or surgical anesthesia.〔When used in anesthesia to produce and maintain unconsciousness, "sleep" is metaphorical as there are no regular sleep stages or cyclical natural states; patients rarely recover from anesthesia feeling refreshed and with renewed energy.〕 This group is related to sedatives. Whereas the term ''sedative'' describes drugs that serve to calm or relieve anxiety, the term ''hypnotic'' generally describes drugs whose main purpose is to initiate, sustain, or lengthen sleep. Because these two functions frequently overlap, and because drugs in this class generally produce dose-dependent effects (ranging from anxiolysis to loss of consciousness) they are often referred to collectively as sedative-hypnotic drugs. Hypnotic drugs are regularly prescribed for insomnia and other sleep disorders, with over 95% of insomnia patients being prescribed hypnotics in some countries. Many hypnotic drugs are habit-forming and, due to a large number of factors known to disturb the human sleep pattern, a physician may instead recommend changes in the environment before and during sleep, better sleep hygiene, and the avoidance of caffeine or other stimulating substances before prescribing medication for sleep. When prescribed, hypnotic medication should be used for the shortest period of time possible. Most hypnotics prescribed today are either benzodiazepines or nonbenzodiazepines. Early classes of drugs, such as barbiturates, have fallen out of use in most practices but are still prescribed for some patients. In children, prescribing hypnotics is not yet acceptable unless used to treat night terrors or somnambulism. Elderly people are more sensitive to potential side effects of daytime fatigue and cognitive impairments, and a meta-analysis found that the risks generally outweigh any marginal benefits of hypnotics in the elderly.〔 〕 A review of the literature regarding benzodiazepine hypnotics and Z-drugs concluded that these drugs can have adverse effects, such as dependence and accidents, and that optimal treatment uses the lowest effective dose for the shortest therapeutic time period, with gradual discontinuation in order to improve health without worsening of sleep. Falling outside of the above-mentioned categories, the neuro-hormone melatonin has a hypnotic function. ==History== Research about using medications to treat insomnia evolved throughout the last half of the 20th century. Treatment for insomnia in psychiatry dates back to 1869 when chloral hydrate was first used as a soporific.〔 Barbiturates emerged as the first class of drugs that emerged in the early 1900s, after which chemical substitution allowed derivative compounds. Although the best drug family at the time (less toxic and with fewer side effects) they were dangerous in overdose. During the 1970s, quinazolinones and benzodiazepines were introduced as safer alternatives to replace barbiturates; by the late 1970s benzodiazepines emerged as the safer drug. Benzodiazepines are not without their drawbacks; substance dependence is possible, and deaths from overdoses sometimes occur, especially in combination with alcohol and/or other depressants. Questions have been raised as to whether they disturb sleep architecture. Nonbenzodiazepines are the most recent development (1990s–present). Although it's clear that they are less toxic than their predecessors, barbiturates, comparative efficacy over benzodiazepines have not been established. Without longitudinal studies, it is hard to determine; however some psychiatrists recommend these drugs, citing research suggesting they are equally potent with less potential for abuse. Other sleep remedies that may be considered "sedative-hypnotics" exist; psychiatrists will sometimes prescribe medicines off-label if they have sedating effects. Examples of these include mirtazapine (an antidepressant), clonidine (generally prescribed to regulate blood pressure), quetiapine (an antipsychotic), and the over-the-counter sleep aid diphenhydramine (Benadryl – an antihistamine). Off-label sleep remedies are particularly useful when first-line treatment is unsuccessful or deemed unsafe (for example, in patients with a history of substance abuse). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「hypnotic」の詳細全文を読む スポンサード リンク
|