The first such drug , chlordiazepoxide ( Librium ) , was discovered accidentally by Leo Sternbach in 1955 , and made available in 1960 by Hoffmann-La Roche , which has also marketed the benzodiazepine diazepam ( Valium ) since 1963 .
The first benzodiazepine , chlordiazepoxide ( Librium ) , was discovered accidentally by Leo Sternbach in 1955 , and made available in 1960 by Hoffmann-La Roche .