Evaluating the Effect of Oral N-acetylcysteine as an Adjuvant Treatment on Clinical Outcomes of Patients with Rheumatoid Arthritis: A Randomized, Double Blind Clinical Trial.

OBJECTIVE: Oxidative stress and Overproduction of pro-inflammatory cytokines are contributed in Rheumatoid Arthritis (RA) pathogenesis. N-acetylcysteine (NAC) is an antioxidant and antiinflammatory agent which demonstrated analgesic effects in some studies. This study is designed to assess the effects of oral NAC as an adjuvant therapy on the clinical outcomes of patients with active RA.

METHODS: In this randomized clinical trial, 51 RA patients with active RA were studied in 2 groups: NAC group (27 patients) received standard treatment of RA and 600 mg NAC twice a day for 12 weeks, and placebo group (24 patients) received the standard treatment of RA and placebo. Disease activity score (DAS28) was used to assess the activity of RA, Visual Analog Scale (VAS) for the severity of pain, Health Assessment Questionnaire (HAQ) for the patients' physical performance, and Global Health (GH) parameter for the patients' assessment of their disease activity. The number of tender and swollen joints and Erythrocyte Sedimentation Rate (ESR) were also determined for each patient. Data were analyzed using SPSS version 16.0 (Chicago, IL, USA).

RESULTS: After 12 weeks of intervention, there were no significant differences between two groups in DAS28 score and ESR (P values were 0.4 and 0.6, respectively). However, GH, VAS, and HAQ scores were improved significantly in the NAC group compared to the placebo group.

CONCLUSION: Our findings indicate that oral administration of NAC may be associated with improving health status in RA patients and considered as an adjuvant therapy in these patients. Further studies with larger sample size, longer study duration and higher doses of NAC are needed to confirm the effects of oral NAC in RA patients.