Description

Tenoxicam is a non-steroidal anti-inflammatory drug (NSAID) with anti-inflammatory, analgesic and antipyretic properties and it also inhibits platelet aggregation. Tenoxicam inhibits prostaglandin biosynthesis. In-vitro tests of leukocyte peroxidase suggest that tenoxicam may act as a scavenger for active oxygen at the site of inflammation. Tenoxicam is a potent in-vitro inhibitor of human metalloproteinases (stromelysin and collagenase), which induce cartilage breakdown. These pharmacological effects explain, at least in part, the therapeutic benefit of Tenoxicam in the treatment of painful inflammatory and degenerative disorders of the musculoskeletal system. Tenoxicam showed no mutagenic, carcinogenic or teratogenic effects in animals. As with other prostaglandin inhibitors, renal and gastrointestinal effects, increased incidence of dystocia and delayed parturition were observed in animal safety studies.

As in the case of other NSAIDs, salicylate displaces tenoxicam from protein-binding sites and increases clearance and volume of distribution of tenoxicam. Concurrent treatment with salicylate or other NSAIDs should be avoided because of increased risk of gastrointestinal undesirable reactions. The co-administration of some NSAIDs and methotrexate has been associated with reduced renal tubular secretion of methotrexate, higher plasma concentrations of methotrexate, and severe methotrexate toxicity. Therefore, caution should be exercised when Tenoxicam is administered concurrently with methotrexate. No clinically relevant interaction was found in the small number of patients receiving concomitant treatment with gold, penicillamine or probenecid. As Tenoxicam may decrease the renal clearance of lithium, their concomitant administration may lead to increased plasma levels and toxicity of lithium. The plasma levels of lithium should be closely monitored. As with NSAIDs in general, Tenoxicam should not be administered concurrently with K-sparing diuretics. There is a known interaction between these two classes of compounds, which may cause hyperkalemia and renal failure. No clinically significant interaction between Tenoxicam and furosemide was noted, but Tenoxicam attenuates the blood pressure-lowering effect of hydrochlorothiazide. As known from other NSAIDs, Tenoxicam might attenuate the antihypertensive effects of alpha-adrenergic blockers and ACE-inhibitors. No interactions have been reported between NSAIDs and centrally-acting alpha agonists or calcium channel blockers. There was no clinically relevant interaction when Tenoxicam was administered together with atenolol. During clinical trials no interaction was reported for patients treated concomitantly with digitalis products. Thus concurrent dosing of Tenoxicam and digoxin appears to be without major risk. No interaction has been found with concomitantly administered antacids, cimetidine, warfarin and phenprocoumon at the recommended dosages. The clinical effect of oral antidiabetic drugs (glibornuride, glibenclamide, tolbutamide) was likewise not modified by Tenoxicam. Nevertheless, careful monitoring is recommended when patients concomitantly receive anticoagulants or oral antidiabetic drugs. No clinically relevant interaction has been found between Tenoxicam and low molecular weight heparin.

Tenoxicam must not be administered to patients: known to be hypersensitive to the drug; in whom salicylates or other non-steroidal anti-inflammatory drugs (NSAIDs) induce symptoms of asthma, rhinitis, or urticaria; suffering or having suffered from the disease of the upper gastrointestinal tract, such as gastritis, gastric and duodenal ulcer.

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.

NSAIDs have an inhibitory effect on prostaglandin synthesis and, when given during late pregnancy, may cause the closure of the fetal ductus arteriosus, prolong labor and delay parturition. Treatment during the third trimester of pregnancy should be avoided. Based on findings from single-dose administration, a very small amount (approximately 0.2%) of tenoxicam passes into breast milk. There is no evidence of adverse reactions in breast-fed infants of mothers taking Tenoxicam. Nevertheless, infants should be weaned or the drug discontinued.