From the digestive system: loss of appetite, nausea, vomiting, flatulence, increased salivation, abdominal pain, diarrhea or constipation, colic pain in the abdomen (with a high infusion rate), peptic ulcer with bleeding, drug-induced hepatitis (including fatal), increased activity of "hepatic" transaminases, jaundice, hyperbilirubinemia, hepatic insufficiency, heartburn.
From the urinary system: proteinuria, hematuria, crystalluria, albuminuria, cylindruria, increased urea concentration in blood plasma, glucosuria.
From the hematopoietic system: leukopenia (up to agranulocytosis), thrombocytopenia, a decrease in prothrombin, an increase in prothrombin time, accompanied by bleeding and hemorrhagic purpura, neutropenia, lymphocytosis, B 12-deficiency megaloblastic anemia, hemolytic anemia with a positive breakdown of Coombs.
Allergic reactions: rash (hives, purpura, enanthema, exfoliative dermatitis, erythema, a syndrome resembling infectious mononucleosis or lymphoma), eosinophilia, bronchospasm, arthralgia, fever, Quincke's edema, Stevens-Johnson syndrome, Lyell syndrome, anaphylactic shock.
Other: hypothyroidism, goiter, myxedema, hypokalemia, acidosis, hypoglycemia, hyperglycemia, Leffler's syndrome (eosinophilic pneumonia, migratory pulmonary infiltrate), swelling of the joints, psychosis, paralysis, seizures, superinfection, reactions similar to lupus erythematosus, accompanied by lesions of the spleen, liver, kidneys, digestive tract, bone marrow and nervous system (for example,pain of radicular nature, meningism), pericarditis, optic neuritis, vasculitis, encephalopathy, itching.
Reactions at the site of administration: possibly the appearance of hematomas and phlebitis.