Application Of Non Steroidal Anti Rheumatic Drugs In The Treatment Of Ankylosing Spondylitis

Objective: To investigate the application of non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of ankylosing spondylitis (AS), including the optimal therapeutic course, safety in long-term therapy, and the drug withdrawal indication.Methods: A total of 250 cases were included. All patients were treated with conventional anti-rheumatic drugs and followed up. Clinical data including symptoms, spinal function, Bath disease activity index (BASDAI), Bath functional index (BASFI), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), blood routine examination, liver function, kidney function, imaging examination as well as the response to drugs were recorded. Statistical analyses were performed with SPSS software, version 13.0.Results: The mean continuous duration of NSAIDs therapy of the 250 patients was 1.5 years, 202 (80.8%) of which were treated more than 1 year, while 87 (34.7%) patients were treated more than 2 years. Among the 250 cases, 150 patients received a dose of NSAIDs at night and a low dose of glucocorticoids (GCs)(equivalent to prednisone≤10mg) in the morning(GCs group)when the diagnosis was established. 34 cases received GCs after 1 month to 1 year of the NSAIDs treatment (later added GCs group), and another 66 cases never received GCs treatment (no GCs group). All of the patients were treated with 1 or more disease modifying anti-rheumatic drugs (DMARDs) at the same time.Compared with the later added GCs group and no GCs group in combination, significantly longer duration of morning stiffness, higher proportion of night pain, worse in spinal function as well as higher score of BASDAI and patient's global assessment were demonstrated in GCs group. However, statistically significant improvement of all of the outcome variables was found in both groups after 1 month of treatment. The percentage of symptom improvement was 96.4% and 95.5%, respectively. ASAS20 and ASAS40 response was achieved by 59.6%, 56.5% and 19.6%, 21.7%, respectively. Compared with no GCs group, significantly worse in spinal function and higher level of ESR or CRP was demonstrated in both GCs group and later added GCs group. Moreover, significantly longer duration of morning stiffness and higher score of BASDAI was showed in GCs group.85 patients withdrew NSAIDs after about one year of treatment. Symptom relapse occurred in 42 cases and no symptom relapse in 43 cases after the withdrawal of NSAIDs. At the point of NSAIDs withdrawal, significant difference of the clinical variables between these two groups was found. A higher proportion of night pain, longer duration of morning stiffness, more number of peripheral joints involved, higher level of ESR, higher score of BASDAI and BASFI as well as higher proportion of patients abruptly withdrawn was demonstrated in symptom relapse group, while the proportion of patients with no symptom and (or) no abnormality of ESR/CRP and patients withdrawn due to disease being controlled was lower.Adverse drug reaction including gastrointestinal, neural, hematological and mucocutaneous system involvement occurred in 39 individual. 8 patients (3.2%) withdrew NSAIDs due to adverse events. All of the adverse events were mild and moderate,and no serious adverse events occurred.Conclusion: NSAIDs is effective in symptom remission,safe and well-tolerated in the treatment of AS. A night time dose of NSAIDs is especially efficacious in releasing night pain and morning stiffness. For patients with mild disease, a night time dose of NSAIDs is sufficient in controlling the symptom, while for those with a severe disease, combination with a morning low dose GCs is needed. The withdrawal of NSAIDs treatment couldn't be done unless the disease activity has been controlled and the dose of NSAIDs has been reduced gradually.