Diazepam, first marketed as Valium by Hoffmann-La Roche, is a benzodiazepine derivative drug. It possesses anxiolytic, anticonvulsant, hypnotic, sedative, skeletal muscle relaxant, and amnestic properties. It is commonly used for treating anxiety, insomnia, seizures, muscle spasms, restless legs syndrome, alcohol withdrawal, benzodiazepine withdrawal, and Ménière's disease. It may also be used before certain medical procedures (such as endoscopies) to reduce tension and anxiety, and in some surgical procedures to induce amnesia. Diazepam is a core medicine in the World Health Organization's "Essential Drugs List," which is a list of minimum medical needs for a basic health care system. Diazepam is used to treat a wide range of conditions and has been one of the most frequently prescribed medications in the world for the past 40 years. It was first synthesized by Dr. Leo Sternbach.