Based on clinical trials including large numbers of patients, Tenoxicam proved to be well tolerated in the recommended dose. Usually, the undesirable effects reported were mild and transient. In a small proportion of patients, the interruption of treatment due to undesirable effects was necessary. Local tolerance of Tenoxicam given parenterally was good. The following undesirable effects have been reported: Frequency is greater than 1%- Gastrointestinal tract: gastric, epigastric and abdominal discomfort, dyspepsia, heartburn, nausea. Central nervous system: dizziness, headache. Frequency less than 1%- Gastrointestinal tract: constipation, diarrhea, stomatitis, gastritis, vomiting, ulcers, Gl-bleeding including hematemesis and melena. Central nervous system: fatigue, sleep disturbances, appetite loss, dry mouth, vertigo. Skin: itching (also in the anal region after rectal administration), erythema, exanthema, rash, urticaria. Urinary tract and kidneys: increase in BUN or creatinine, edema. Liver and biliary tract: increased liver enzyme activity. Cardiovascular system: palpitations. Isolated cases (frequency less than 0.01%)- Gastrointestinal tract: Gl-perforation. Central nervous system: visual disturbances. Skin: Stevens-Johnson and Lyell's syndrome, photosensitivity reaction, vasculitis. Blood: anemia, agranulocytosis, leukopenia, thrombocytopenia. Hypersensitivity reactions: dyspnea, asthma, anaphylaxis, angioedema. Cardiovascular system: elevated blood pressure, mainly in patients treated with cardiovascular drugs. Liver/Biliary tract: hepatitis.