• Individuals aged >50 years with spinal stenosis were randomized to receive epidural injections of local anesthetic with corticosteroid (n = 200) or local anesthetic only (n = 200) to evaluate the risk of cortisol suppression associated with epidural corticosteroids. Cortisol reduction of >50% at 3 weeks was seen in 20.3% of corticosteroid-treated participants versus 6.7% of those treated with local anesthetic only (P = .002). The average 3-week cortisol reduction from baseline was 41.0% in participants treated with methylprednisolone (P = .005) and 41.6% in those treated with triamcinolone (P <.001). In contrast, participants treated with betamethasone or dexamethasone had a cortisol reduction comparable to that of the local anesthetic only group.
• There is sustained systemic absorption of corticosteroid resulting in cortisol suppression in individuals treated with epidural corticosteroid injections, especially in those receiving longer-acting insoluble corticosteroid formulations.

Abstract

This analysis of the Lumbar Epidural steroid injections for Spinal Stenosis (LESS) multi-center randomized controlled trial data identifies the degree of and risk factors for cortisol suppression following epidural steroid injections in older adults with spinal stenosis. 400 patients aged > 50 years with back or leg pain and central lumbar spinal stenosis completed baseline demographic and psychosocial measures. Morning serum cortisol levels were measured at baseline and 3 weeks after initial injection. Patients were randomized to receive epidural injections of either local anesthetic with corticosteroid (n = 200) or local anesthetic only (n = 200). The specific corticosteroid was chosen at the treating physician’s discretion (methylprednisolone, betamethasone, triamcinolone or dexamethasone). Thirty-two patients (20.3%) treated with corticosteroid experienced cortisol reduction at 3 weeks of >50% compared to 10 patients (6.7%) treated with lidocaine only (adjusted treatment effect = 3.5, 95% CI (1.6, 7.9), P=0.002). The effect on 3-week cortisol changes did not differ by demographic or patient-level characteristics. Those treated with methylprednisolone or triamcinolone had an average 3-week cortisol reduction of 41.0% (P=0.005) and 41.6% (P<0.001) from baseline respectively whereas patients treated with betamethasone or dexamethasone were not significantly different than comparable patients in the lidocaine arm. The higher rates of cortisol suppression at three weeks in those receiving epidural corticosteroid injections, particularly with longer-acting insoluble corticosteroid formulations, are consistent with sustained systemic absorption of corticosteroid.

Journal Abstract