1,6-Dimethyl-3-carbethoxy-4-oxo-6,7,8,9-tetrahydro-homopyrimidazol (rimazolium, MZ-144) is an analgesic (non-narcotic). It proved to be effective in all the analgesic assays used (independently of the nociceptive stimulus applied) (hot plate, tail flick, writhing tests, Randall-Selitto test, tail clip, surgical pain) differing in this respect from the nonsteroidal antiinflammatory analgetics. Rimazolium lacks the capacity of producing opiate-like physiological dependence. Also rimazolium fails to show any indication of narcotic-like abuse liability by any of clinical assessments. Rimazolium is registered in Hungary under the brand name Probon. In Hungary among analgesics Probon is the first of choice especially in case of chronic pain accompanying chronic respiratory tract diseases.