The effect of tacrolimus conversion from immediate- to extended-release formulation on renal function in renal transplant patients: a meta-analysis

Objective: Tacrolimus formulation affects the outcomes of a renal transplant, while the effect of its immediate- to extended-release conversion remains controversial. This meta-analysis aimed to compare the renal function before and after tacrolimus immediate- to extended-release conversion in renal transplant patients.Methods: PubMed, Cochrane, Embase, CNKI, CQVIP, and Wanfang databases were searched for articles regarding the effect of tacrolimus conversion from immediate- to extended-release formulation on renal function in renal transplant patients. The data on serum creatinine (Scr) or the estimated glomerular filtration rate (eGFR) before and after conversion were extracted and analyzed.Results: Ten studies with 743 renal transplant patients were included. Scr was reduced after conversion versus before conversion [mean difference (MD) (95% confidence interval (CI)): -8.00 (-14.33; -1.66) mu mol/L, p = 0.01]. However, eGFR only showed an increased trend after conversion versus before conversion (MD (95% CI): 2.21 (-1.62, 6.03) mL/min/1.73 m(2), p = 0.26) but without statistical significance. Furthermore, in patients with a follow-up duration >= 48 weeks, Scr was decreased after conversion versus before conversion (p = 0.005), but eGFR remained unchanged (p = 0.68). However, in patients with a follow-up duration <48 weeks, both Scr (p = 0.36) and eGFR (p = 0.24) were not different before conversion versus after conversion. Moreover, publication bias risk was low, and robustness assessed by sensitivity analysis was generally good.Conclusion: This meta-analysis favors studies indicating that the conversion of tacrolimus from an immediate-release to an extended-release formulation could improve the kidney function to some extent in renal transplant patients, and this advancement may be related to the administration period.