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Benzodiazepine withdrawal syndrome—often abbreviated to benzo withdrawal—is the cluster of symptoms that emerge when a person who has taken benzodiazepines, either medically or recreationally, and has developed a physical dependence undergoes dosage reduction or discontinuation. Development of physical dependence and or addiction and the resulting withdrawal symptoms, some of which may last for years, may result from either drug seeking behaviors or from taking the medication as prescribed. Benzodiazepine withdrawal is characterized by sleep disturbance, irritability, increased tension and anxiety, panic attacks, hand tremor, sweating, difficulty with concentration, confusion and cognitive difficulty, memory problems, dry retching and nausea, weight loss, palpitations, headache, muscular pain and stiffness, a host of perceptual changes, hallucinations, seizures, psychosis, and suicide〔 (see "Signs and Symptoms" section below for full list). Further, these symptoms are notable for the manner in which they wax and wane and vary in severity from day to day or week by week instead of steadily decreasing in a straightforward monotonic manner. It is a potentially serious condition, and is complex and often protracted in time course.〔(【引用サイトリンク】 year= 2002 )〕 Long-term use, defined as daily use for at least three months, is not desirable because of the associated increased risk of dependence, dose escalation, loss of efficacy, increased risk of accidents and falls, particularly for the elderly, as well as cognitive, neurological, and intellectual impairments. Use of short-acting hypnotics, while being effective at initiating sleep, worsen the second half of sleep due to withdrawal effects. Nevertheless, long-term users of benzodiazepines should not be forced to withdraw against their will.〔 Benzodiazepine withdrawal can be severe and can provoke life-threatening withdrawal symptoms, such as seizures, particularly with abrupt or overly-rapid dosage reduction from high doses or long time users.〔 A severe withdrawal response can nevertheless occur despite gradual dose reduction, or from relatively low doses in short time users, even after a single large dose in animal models. A minority of individuals will experience a protracted withdrawal syndrome whose symptoms may persist at a sub-acute level for months, or years after cessation of benzodiazepines. The likelihood of developing a protracted withdrawal syndrome can be minimized by a slow, gradual reduction in dosage.〔 Chronic exposure to benzodiazepines causes neural adaptations that counteract the drug's effects, leading to tolerance and dependence.〔 Despite taking a constant therapeutic dose, long-term use of benzodiazepines may lead to the emergence of withdrawal-like symptoms, particularly between doses. When the drug is discontinued or the dosage reduced, withdrawal symptoms may appear and remain until the body reverses the physiological adaptations. These rebound symptoms may be identical to the symptoms for which the drug was initially taken, or may be part of discontinuation symptoms. In severe cases, the withdrawal reaction may exacerbate or resemble serious psychiatric and medical conditions, such as mania, schizophrenia, and, especially at high doses, seizure disorders.〔 Failure to recognize discontinuation symptoms can lead to false evidence for the need to take benzodiazepines, which in turn leads to withdrawal failure and reinstatement of benzodiazepines, often to higher doses.〔 Awareness of the withdrawal reactions, individualized taper strategies according to withdrawal severity, the addition of alternative strategies such as reassurance and referral to benzodiazepine withdrawal support groups, all increase the success rate of withdrawal. ==Signs and symptoms== Withdrawal effects caused by sedative-hypnotics discontinuation, such as benzodiazepines, barbiturates, or alcohol, can cause serious medical complications. They are cited to be more hazardous to withdraw from than opioids. Users typically receive little advice and support for discontinuation. Some withdrawal symptoms are identical to the symptoms for which the medication was originally prescribed,〔 and can be acute or protracted in duration. Onset of symptoms from long half-life benzodiazepines might be delayed for up to three weeks, although withdrawal symptoms from short-acting ones often present early, usually within 24–48 hours.〔 There may be no fundamental differences in symptoms from either high or low dose discontinuation, but symptoms tend to be more severe from higher doses. Daytime reemergence and rebound withdrawal symptoms, sometimes called interdose withdrawal, may occur once dependence has set in. Reemergence is the return of symptoms for which the drug was initially prescribed, in contrast, rebound symptoms are a return of the symptoms for which the benzodiazepine was initially taken for, but at a more intense level than before. Withdrawal symptoms, on the other hand, may appear for the first time during dose reduction, and include insomnia, anxiety, distress, weight loss, panic, depression, derealization, and paranoia, and are more commonly associated with short-acting benzodiazepines discontinuation, like triazolam.〔 Daytime symptoms can occur after a few days to a few weeks of administration of nightly benzodiazepine use or z-drugs such as zopiclone; withdrawal-related insomnia rebounds worse than baseline even when benzodiazepines are used intermittently. The following symptoms may emerge during gradual or abrupt dosage reduction: Rapid discontinuation may result in a more serious syndrome As withdrawal progresses, patients often find their physical and mental health improves with improved mood and improved cognition. 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「Benzodiazepine withdrawal syndrome」の詳細全文を読む スポンサード リンク
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