Tramadol/Acetaminophen(Ultracet) AS add-on Therapy in the Treatment of Patients With Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory arthritis causing back pain, peripheral arthritis and enthesitis due to genetic background and autoimmunity. Patients with ankylosing spondylitis usually suffered from chronic pain over spine and peripheral joints since their second or third decades. It may also cause severe social and psychological burden to patients and their family.

Exercise and non-steroid anti-inflammatory drugs (NSAID) are the standard first-line treatments for AS（1）. Only 50% of patients with AS reach the ASAS response criteria（2） in clinical trials. Patients with severe disease activity should be put on disease-modifying anti-rheumatic drugs (DMARD), such as sulfasalazine（3） and anti-TNF biological agents. Add-on of acetaminophen and low dose anti-depressant （4）can slightly improve the response rate. However, there is no data if tramadol or ultracet can benefit AS.

Inclusion criteria

• Diagnosis of AS, as defined by Modified New York Criteria for Ankylosing Spondylitis
• Active AS, defined by Bath ankylosing spondylitis disease activity index (BASDAI) >3 cm at screening visit.
• Between 18 and 70 years of age.

Exclusion criteria

• Change of dosage of disease modifying antirheumatic drugs (DMARDs) including glucocorticoid, hydroxychloroquine, sulphasalazine, and methotrexate within 4 weeks of baseline.
• Change of dosage of biological agents within 4 weeks of baseline.
• Abnormality in chemistry profiles: serum creatinine 3.0 mg/dl; alanine aminotransferase (ALT[SGPT]) 5 times the laboratory's upper limit of normal.
• Pregnant or breast-feeding women.