Abstract: SA-PO287
When Hepatic Therapy Backfires: Unraveling the Intricacies of Rifaximin-Induced Rhabdomyolysis Post-Transplantation
Session Information
- Pharmacology: Kinetics, Genomics, Medication-Related Problems
November 04, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pharmacology (PharmacoKinetics, -Dynamics, -Genomics)
- 2000 Pharmacology (PharmacoKinetics, -Dynamics, -Genomics)
Authors
- Vilayet, Salem, Medical University of South Carolina, Charleston, South Carolina, United States
- Uehara, Genta, Medical University of South Carolina, Charleston, South Carolina, United States
- Soliman, Karim, Medical University of South Carolina, Charleston, South Carolina, United States
Introduction
Rhabdomyolysis, a severe condition marked by muscle cell content leakage into circulation, manifests as weakness, pain, swelling, and myoglobinuria. It can result from diverse causes, leading to complications like acute kidney injury (AKI). We report a case of rifaximin-induced rhabdomyolysis.
Case Description
A 56-year-old male with a pancreas-kidney transplant, and cholestatic/drug-induced cirrhosis due to lacosamide (Stage 1 fibrosis on biopsy, now Stage IV). The initial presentation included weakness and altered mental state; labs revealed hyperammonemia (155 umol/L), elevated tacrolimus level (9.7 ng/mL), and creatinine (1.7mg/dL). He was started on intravenous fluids, rifaximin, lactulose, and continuation of his atorvastatin, resolved hepatic encephalopathy, and improved creatinine to 1.4 mg/dL.
He returned three weeks later with increased weakness and leg pain. Labs showed elevated creatinine kinase (14614 U/L), creatinine peaking at 4.5 mg/dL, and a tacrolimus level of 8.9 ng/mL. A renal biopsy suggested acute tubular injury, rhabdomyolysis-induced pigment nephropathy, and borderline acute rejection.
Management included pulse-dose solumedrol (500mg/3 days), followed by a taper, discontinuation of rifaximin, intravenous fluids, and dose reduction of tacrolimus, leading to resolution of rhabdomyolysis and improved kidney injury.
Discussion
In this case, rifaximin, a medication started during the patient's initial presentation, likely caused the rhabdomyolysis. Despite its limited gut absorption, hepatic impairment may enhance absorption. The mechanism could involve rifampin-induced mitochondrial oxidative stress in muscle, promoting myofibrillar proteolysis, similar to statin-induced rhabdomyolysis. This case underscores rifaximin's potential for inducing rhabdomyolysis, especially in patients with hepatic impairment.
Figure 1: Hematoxylin and eosin stain of renal tubules notable for brown pigment in cytoplasm and granular cast