High daily doses of prednisolone may put children with systemic lupus erythematosus (SLE) at significant risk of avascular necrosis (AVN), reports a recent study.
Drawing from Taiwan’s National Health Insurance Research Database, the researchers identified 1,472 children (mean age at diagnosis, 15.5±3.3 years; 86.1 percent girls) who had been diagnosed with SLE between 2005 and 2013. The primary outcome was the development of AVN, assessed with respect to medications taken.
Over an average follow-up duration of 4.6±2.5 years, 39 patients (37 girls and two boys) developed AVN, yielding an incidence rate of 2.6 percent. Almost all patients (92.7 percent; n=1,364) were on disease-modifying antirheumatic drugs (DMARDs), of which hydroxychloroquine was most common.
AVN patients saw a significantly shorter cumulative duration of hydroxychloroquine exposure (544.2±580.1 vs 804.1±727.2 days; p=0.009), although cyclophosphamides were more frequently used in this subgroup (46.2 percent vs 28.3 percent; p=0.015). Majority of the patients (95.5 percent; n=1,406) were prescribed systemic corticosteroids.
Multivariate Cox proportional hazards analysis showed that a higher daily dose of prednisolone, between 7.5 and 30 mg, was associated with a significantly elevated risk of developing AVN (hazard ratio [HR], 7.435, 95 percent confidence interval [CI], 2.882–19.178; p<0.001). This effect was even stronger for patients who were taking >30 mg of prednisolone per day (HR, 9.366, 95 percent CI, 2.225–39.418; p=0.002). Both risk estimates were in comparison to children on ≤75-mg/day of the medication.