Chlordiazepoxide, trade name Librium among others, is a sedative and hypnotic medication of the benzodiazepine class; it is used to treat anxiety, insomnia and symptoms of withdrawal from alcohol and other drugs. Chlordiazepoxide has a medium to long half-life but its active metabolite has a very long half-life. The drug has amnesic, anticonvulsant, anxiolytic, hypnotic, sedative and skeletal muscle relaxant properties.Chlordiazepoxide was patented in 1958 and approved for medical use in 1960. It was the first benzodiazepine to be synthesized and the discovery of chlordiazepoxide was by pure chance. Chlordiazepoxide and other benzodiazepines were initially accepted with widespread public approval but were followed with widespread public disapproval and recommendations for more restrictive medical guidelines for its use. Medical uses
Chlordiazepoxide is indicated for the short-term (2–4 weeks) treatment of anxiety that is severe and disabling or subjecting the person to unacceptable distress. It is also indicated as a treatment for the management of acute  alcohol withdrawal syndrome.It can sometimes be prescribed to ease symptoms of irritable bowel syndrome combined with clidinium bromide as a fixed dose medication, Librax. Contraindications
Use of chlordiazepoxide should be avoided in individuals with the following conditions:

Myasthenia gravis
Acute intoxication with alcohol, narcotics, or other psychoactive substances
Ataxia
Severe hypoventilation
Acute narrow-angle glaucoma
Severe liver deficiencies (hepatitis and liver cirrhosis decrease elimination by a factor of 2)
Severe sleep apnea
Hypersensitivity or allergy to any drug in the benzodiazepine classChlordiazepoxide is generally considered an inappropriate benzodiazepine for the elderly due to its long elimination half-life and the risks of accumulation.
During studies, chlordiazepoxide induced muscle relaxation and a quieting effect on laboratory animals like mice, rats, cats, and dogs. Fear and aggression were eliminated in much smaller doses than those necessary to produce hypnosis. Chlordiazepoxide is similar to phenobarbital in its anticonvulsant properties. However, it lacks the hypnotic effects of barbiturates. Animal tests were conducted in the Boston Zoo and the San Diego Zoo. Forty-two hospital patients admitted for acute and chronic alcoholism, and various psychoses and neuroses were treated with chlordiazepoxide. In a majority of the patients, anxiety, tension, and motor excitement were "effectively reduced." The most positive results were observed among alcoholic patients. It was reported that ulcers and dermatologic problems, both of which involved emotional factors, were reduced by chlordiazepoxide.In 1963, approval for use was given to diazepam (Valium), a "simplified" version of chlordiazepoxide, primarily to counteract anxiety symptoms. Sleep-related problems were treated with nitrazepam (Mogadon), which was introduced in 1972, temazepam (Restoril), which was introduced in 1979, and flurazepam (Dalmane), which was introduced in 1975. Recreational use
In 1963, Carl F. Essig of the Addiction Research Center of the National Institute of Mental Health stated that meprobamate, glutethimide, ethinamate, ethchlorvynol, methyprylon and chlordiazepoxide were drugs whose usefulness “can hardly be questioned.” However, Essig labeled these “newer products” as “drugs of addiction,” like barbiturates, whose habit-forming qualities were more widely known. He mentioned a 90-day study of chlordiazepoxide, which concluded that the automobile accident rate among 68 users was 10 times higher than normal.