Yep. This is an approved protocol in several U.S. states. Amitriptyline can be swapped out for propranolol, in a mixture known—logically—as DDMP. Actually, the mixture with propranolol is more common. The issue is that this mixture kind of takes away the appeal of using amitriptyline/propranolol in being so easy to obtain, as the valium and, especially, the morphine are very difficult to get ahold of in the quantities required.
Also, there is an amitriptyline entry in the PPH.