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Phenobarbital, also known as phenobarbitone, is a medication recommended by the World Health Organization for the treatment of certain types of epilepsy in developing countries. In the developed world it is commonly used to treat seizures in young children, while other medications are generally used in older children and adults.〔(【引用サイトリンク】)">website=National Institute for Health and Care Excellence )〕 It may be used intravenously, injected into a muscle, or taken by mouth.〔 The injectable form may be used to treat status epilepticus.〔 Phenobarbital is occasionally used to treat trouble sleeping, anxiety, drug withdrawal, and to help with surgery.〔(【引用サイトリンク】url=http://www.drugs.com/monograph/phenobarbital.html )〕 It usually begins working within five minutes when used intravenously and half an hour when administered orally.〔 Its effects last for between four hours and two days.〔 Side effects include a decreased level of consciousness along with a decreased effort to breathe. There is concern about both abuse and withdrawal following long term use. It may also increase the risk of suicide.〔 It is pregnancy category B or D in the United States and category D in Australia, meaning that it may cause harm when taken by pregnant women.〔 If used during breastfeeding it may result in drowsiness in the baby.〔(【引用サイトリンク】url=http://www.drugs.com/breastfeeding/phenobarbital.html )〕 A lower dose is recommended in those with poor liver or kidney function, as well as elderly people.〔 Phenobarbital is a barbiturate that works by increasing the activity of the inhibitory neurotransmitter GABA.〔 Phenobarbital was discovered in 1912 and is the oldest still commonly used anti-seizure medication. It is a ''core'' medicine in the WHO Model List of Essential Medicines, the minimum medications needed for a basic health care system. It is the least expensive anti-seizure medication at around $5 USD a year.〔 Access however may be difficult as some countries label it as a controlled drug. == Medical uses == Phenobarbital is used in the treatment of all types of seizures except absence seizures.〔British National Formulary 51〕 It is no less effective at seizure control than more recent drugs such as phenytoin and carbamazepine. It is, however, less well tolerated. The World Health Organization gives it a first-line recommendation in the developing world and it is commonly used there.〔 Its very long active half-life means for some people doses do not have to be taken every day, particularly once the dose has been stabilized over a period of several weeks or months, and seizures are effectively controlled. The first-line drugs for treatment of status epilepticus are benzodiazepines, such as lorazepam or diazepam. If these fail, then phenytoin may be used, with phenobarbital being an alternative in the US, but used only third-line in the UK. Failing that, the only treatment is anaesthesia in intensive care.〔 Phenobarbital is the first-line choice for the treatment of neonatal seizures. Concerns that neonatal seizures in themselves could be harmful make most physicians treat them aggressively. No reliable evidence, though, supports this approach. Phenobarbital is sometimes used for alcohol detoxification and benzodiazepine detoxification for its sedative and anticonvulsant properties. The benzodiazepines chlordiazepoxide (Librium) and oxazepam (Serax) have largely replaced phenobarbital for detoxification.〔http://www.aafp.org/afp/980700ap/miller.html〕 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「Phenobarbital」の詳細全文を読む スポンサード リンク
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