Table 1 Inclusion/exclusion criteria

Inclusion

Patients must understand risks and benefits of the protocol and be able to give informed consent

Male and female patients aged 40 to 80 years

Females of child-bearing potential must agree to use an approved form of birth control and to have a negative pregnancy test result.

Unilateral or bilateral osteoarthritis of the knee for more than 3 months

Visual analogue scale score during the most painful knee movement between 40 and 70 mm after 7 days of withdrawal of usual medication

Lequesne's Functional Index score greater than 7 points after 7 days of withdrawal of usual medication

Ability to walk

Availability for the duration of the entire study period

Exclusion

History of underlying inflammatory arthropathy or severe rheumatoid arthritis

Hyperuricaemia (>440 μmol/l) and/or past history of gout

Recent injury in the area affected by osteoarthritis of the knee (past 4 months) and expectation of surgery in the next 4 months

Intra-articular corticosteroid injections within the preceding 3 months

Hypersensitivity to nonsteroidal anti-inflammatory drugs, abnormal liver or kidney function tests, history of peptic ulceration and upper gastrointestinal haemorrhage, congestive heart failure, hypertension, hyperkalaemia

Major abnormal findings on complete blood count, history of coagulopathies, haematological or neurological disorders

High alcohol intake (>2 standard drinks per day)

Pregnant, breastfeeding, or planning to become pregnant during the study

Use of concomitant prohibited medication other than ibuprofen

Obesity (body mass index > 30 kg/m²)