High Quality Content by WIKIPEDIA articles! Papaveretum (BAN) is a preparation containing a mixture of hydrochloride salts of opium alkaloids. Since 1993, papaveretum has been defined in the British Pharmacopoeia (BP) as a mixture of 253 parts morphine hydrochloride, 23 parts papaverine hydrochloride, and 20 parts codeine hydrochloride (Sweetman, 2004). It is commonly marketed to medical agencies under the trade name Omnopon.