The hydrochloride salt of a diacetyl derivative of the opiate morphine, a naturally occurring alkaloid extracted from the seedpod of the Asian poppy (Papaver sp.). Once administered, diamorphine (or diacetylmorphine) is rapidly hydrolyzed to 6-monoacetylmorphine (6-MAM) and then to the end-product morphine which binds to opiate receptors located throughout the mammalian nervous and gastrointestinal systems. Inducing a potent analgesia, the use of diamoprhine is often escalated due to a tolerance effect, resulting in abuse that is associated with fatal overdose, abortion, venous sclerosis, and opportunistic infections, among other adverse effects. Check for active clinical trials using this agent. (NCI Thesaurus)