Hypersensitivity to the drug, to pyrazolone derivatives (phenylbutazone, tribuzon) or other non-steroidal anti-inflammatory drugs (NSAIDs). Severe liver or kidney failure, megacolon, acute hepatic porphyria, a suspicion of surgical pathology, prostate adenoma II and III degree, a congenital deficiency of glucose-6-phosphate dehydrogenase, tachyarrhythmia, closure type of glaucoma, prostatic hypertrophy with tendency to urinary retention, obstruction of the gastrointestinal tract (including mechanical obstruction), or atony of the gall bladder, disorders of the hematopoietic system (agranulocytosis, leukopenia, aplastic anemia), collaptoid states, decompensated heart failure, asthma, hemolytic anemia.