Fludrocortisone is effective in the management of tacrolimus-induced hyperkalemia in liver transplant recipients.

Tacrolimus is the cornerstone of immunosuppression following liver transplantation (OLT). However, this agent may cause hyperkalemia by multiple mechanisms affecting potassium in the distal tubule. The purpose of this study was to evaluate the impact of fludrocortisone for the management of tacrolimus-induced hyperkalemia. Hospitalized adult OLT recipients who received fludrocortisone for tacrolimus-induced hyperkalemia were retrospectively identified. Change in serum potassium within 14 days of initiation was the primary endpoint. Secondary endpoints included serum sodium, blood urea nitrogen, serum creatinine, and tacrolimus concentrations up to 14 days after fludrocortisone initiation. Nine patients were evaluated. Outcomes were analyzed with separate repeated-measures analyses of variance. Mean daily fludrocortisone dose was 0.14 ± 0.08 mg. Serum potassium decreased significantly within the 14-day study period (P < .001). Mean potassium decreased from 5.7 ± 1 to 4.3 ± 0.5 mmol/L within 48 hours of fludrocortisone initiation (P = .002). Sodium concentrations were statistically higher (P = .024), while serum creatinine was not significantly different by day 14. Mean tacrolimus concentration at fludrocortisone initiation was 10.2 ± 5.2 and remained stable to 14 days (10.4 ± 4.7 ng/mL; P = .9). This is the first study in OLT recipients demonstrating fludrocortisone significantly decreases serum potassium in patients with stable tacrolimus concentrations. Larger prospective studies are needed to confirm these results.