Pulse Pamidronate therapy in NSAID refractory ankylosing spondylitis. Is it effective?–An open label study

Abstract

Objective To assess the efficacy of pulse Pamidronate therapy in NSAID refractory ankylosing spondylitis (AS). Patients Fifty two patients of ankylosing spondylitis (fulfilling modified New York criteria), refractory to NSAID and having active disease were enrolled. Active disease was defined as BASDAI = 4 and/or early morning stiffness = 45 minutes despite NSAID therapy. Intervention Monthly intravenous Pamidronate infusions (60 mg) for a period of 6 months along with current NSAID. Primary outcome measure was improvement in BASDAI at the end of therapy. Secondary outcome measures included improvement in BASDAI = 25%, BASFI, metrology parameters, visual analogue scales for pain and global assessment of disease, ESR, CRP, MMP-3 and quality of life domains. Results Out of 52 patients enrolled [47 men; mean age 36.2 years (range 22-53 years) and mean disease duration 7.2 years (3-25 years)], 47 patients completed the study. At 6 months, there were significant improvement in BASDAI ( P < 0.005), BASFI ( P < 0.005), pain ( P < 0.005) and patient global assessment of disease ( P < 0.005) and lateral flexion (P<0.05). However, BASDAI >25% reduction was seen in 29.6% patients only. In addition, quality of life, HAQ and serological markers MMP-3, ESR and CRP were not significantly altered. Most common adverse effects included arthralgias and myalgias, 22.5% each, following initial infusions. There were five withdrawals; two defaults and one for hip joint replacement and two for asymptomatic rise in serum creatinine. Conclusion Pamidronate has modest efficacy in improving the patient reported outcome variables in NSAID refractory AS.