Life-table analysis of cyclosporin A treatment in psoriatic arthritis: Comparison with other disease-modifying antirheumatic drugs

OBJECTIVES: The aim of this study was to determine the cumulative probability of taking Cyclosporin (CsA) in comparison to other DMARDs, as well as the reason for discontinuation of each DMARD, in a large cohort of psoriatic arthrits (PsA) patients. METHODS: We prospectively studied 172 consecutive patients with a diagnosis of PsA who had been admitted to our rheumatological unit since 1984. We collected information about treatment with DMARDs including: number, dose, duration and causes of withdrawal, including side effects or inefficacy. Cumulative survival analysis was performed by the Kaplan-Meier test and the differences between these survival curves were determined by the Mantel-Hanszel test. RESULTS: The probability curve of continuing to take CsA was significantly lower than that of MTX (p < 0.046). The rate of adverse effects responsible for stopping DMARD therapy was higher in the CsA group, especially with respect to the antimalarial group (p < 0.014). The most common cause of CsA withdrawal was hypertension. The rate of withdrawal due to inefficacy in the CsA group was not significantly different from those observed in the other groups. Nevertheless, the total frequency of discontinuation due to toxicity and inefficacy in the MTX group was significantly lower compared to the gold salts (p < 0.05) and CsA groups (p < 0.01). CONCLUSION: Life-table analysis suggests that PsA patients taking CsA are less likely than patients on MTX to continue long term treatment. Therefore CsA, which seems to be less safe than the antimalarials, could be considered a useful drug in the treatment of PsA, but does seem to represent the drug of first choice, particularly when compared to MT