This study is conducted to study the efficacy and safety of Niselat in patients with osteoarthritis.

Osteoarthritis is the most common rheumatic disease. Knee OA (KOA), gonarthrosis (GA), is characterized by high prevalence, progressive course with early disability of the subject, persistent pain syndrome for the treatment of which non-steroidal anti inflammatory drugs (NSAIDs) are actively used in clinical practice. It was revealed that NSAIDs may cause gastrointestinal adverse effects (AEs), from mild dyspepsia to bleeding and perforation as well as cardiovascular effects. Gastroprotection with misoprosol, Н2-receptor antagonists and proton pump inhibitors (PPI) is not always effective. NSAIDs with the lowest gastrointestinal toxicity with efficacy adequate to suppress joint pain is justified and reasonable.

Amtolmetin guacil (AMG) is a new NSAID which proved to be the least gastrointestinally toxic in experimental studies in vivo, in vitro and in comparative clinical studies. AMG does not have selectivity towards COX-2 or NO. AMG exerts gastroprotective effect due to stimulation of capsaicin receptors (vanilloid receptors) in gastrointestinal wall. To assess tolerability of amtolmetin guacil, it is first necessary to obtain data on potential reduction of dyspeptic symptoms including in subjects with these signs of NSAIDs intolerability.

Inclusion Criteria:

1. Informed consent form for participation in the study;
2. KOA (based on ACR, 1987)
3. Age between 30-60 years old
4. Previous regular administration of NSAIDs for at least 4 weeks (at maximum therapeutic dose)
5. Dyspeptic symptoms (according to SODA questionnaire)
6. Pain intensity in the investigated knee joint ≥ 40 mm according to VAS
7. Subjects with systolic blood pressure ≤ 140 mm Hg and diastolic BP ≤90 mmHg against stable antihypertensive therapy.

Exclusion Criteria:

1. Contraindications to amtolmetin guacil (according to patient information leaflet)
2. Subjects with SBP ≥140 mm Hg and DBP ≥90 mm Hg
3. Signs of renal or hepatic failure;
4. Pregnancy, lactation or planning for pregnancy.
5. One of the following changes in laboratory values at screening HGB, WBC, ESR, ALT, AST.

Subjects with knee osteoarthrosis (KOA)

Under review