Efficacy of Alfacalcidol Versus Calcitriol in Managing Secondary Hyperparathyroidism in Patients With Chronic Kidney Disease.

Background: Data comparing the efficacy of alfacalcidol to that of calcitriol in managing secondary hyperparathyroidism in patients with chronic kidney disease (CKD) is scarce. We sought to compare the efficacy of both drugs in managing hyperparathyroidism in patients with CKD. Methods: A retrospective observational cohort study conducted from January 2022 to March 2023 included adults with CKD stages 3 to 5 (non-dialysis) who received alfacalcidol for 3 months followed by calcitriol for another 3 months. Assessments were done at baseline and after 3 months of each treatment. The primary outcome was iPTH suppression, and the secondary outcome was total serum calcium levels. Results: A total of 70 patients were included, with 34 (48.6%) being male. The cohort's mean age was 65.5 ± 15 years. CKD stage 3 comprised 47.1% of the sample. The median dose of alfacalcidol was 0.5 (0.25-0.8) µg compared to 0.5 (0.25-0.5) µg for calcitriol (P = .001). Alfacalcidol did not significantly suppress iPTH levels, with median values of 13.31 (8.23-24.4) pg/mL at baseline and 12.5 (8.86-24.7) pg/mL after 3 months (P = .937). In contrast, calcitriol significantly reduced iPTH levels from 12.5 (8.86-24.7) pg/mL to 10.7 (5.7-19) pg/mL (P = .017). Additionally, alfacalcidol did not significantly increase calcium levels, while calcitriol did. Throughout the study period, albumin values, the follow-up times, and the use of phosphate binders or non-active vitamin D remained consistent for each drug. The multivariate Generalized Estimating Equations indicated that baseline iPTH [B = 0.041, 95% CI (0.03- 0.05); P < .001], calcitriol [B = -0.278, 95% CI (-0.5 to -0.06); P = .014], daily dose of the study drug [B = -0.45, 95% CI (-0.7 to -0.2); P < .001], and baseline phosphorus level [B = 0.354, 95% CI (0.004-0.7); P = .047] were independent factors associated with iPTH suppression. Conclusion: Calcitriol, at significantly lower doses, was more effective than alfacalcidol in suppressing iPTH levels and increasing calcium levels over 3 months. A randomized controlled study is needed to confirm these findings.