Dipipanone
Dipipanone ( Pipadone ) is a strong opioid analgesic drug , used for very severe pain in cases where other analgesics are unsuitable , for instance where morphine is indicated but cannot be used due to the patient being allergic to morphine . 
<triplet> opioid <subj> analgesic <obj> subclass of <triplet> morphine <subj> opioid <obj> subject has role