Diazepam is used to treat anxiety, acute alcohol withdrawal, and seizures. It is also used to relieve muscle spasms and to provide sedation before medical procedures. This medication belongs to a class of drugs called benzodiazepines which act on the brain and nerves (central nervous system) to produce a calming effect. It works by enhancing the effects of a certain natural chemical in the body (GABA).OTHER This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.This medication may also be used to prevent extremely bad nightmares (night terrors).