Barbiturates have been used as hypnotic and sedative agents, for the induction of anesthesia, and for the treatment of epilepsy and status epilepticus. They have been largely replaced by newer drugs. They often are divided into four major groups according to their pharmacologic activity and clinical use: ultra–short-acting, short-acting, intermediate-acting, and long-acting (Table II–13). Common combination products containing barbiturates include Fiorinal (50 mg of butalbital) and Donnatal (16 mg of phenobarbital). Veterinary euthanasia products often contain barbiturates such as pentobarbital.