Treatment of prolonged tacrolimus toxicity using phenytoin in a haemodialysis patient

• Published in: Journal of clinical pharmacy and therapeutics Vol. 44; no. 4; pp. 640 - 643
• Main Authors: Meaney, Calvin J., O’Connor, Megan, McGowan, Melissa, Hamid, Mohammed, Su, Winnie
• Format: Journal Article
• Language: English
• Published: England Hindawi Limited 01.08.2019
• Subjects: Darunavir - therapeutic use; Drug interaction; Drug Interactions; Drug-Related Side Effects and Adverse Reactions - drug therapy; Encephalopathy; haemodialysis; Hemodialysis; Humans; Immunosuppressive Agents - adverse effects; Kidney transplantation; Male; Metabolism; Middle Aged; Phenytoin; Phenytoin - therapeutic use; Renal Dialysis - methods; Ritonavir; Ritonavir - therapeutic use; Tacrolimus; Tacrolimus - adverse effects; Toxicity; toxicity; haemodialysis; phenytoin; tacrolimus
• ISSN: 0269-4727; 1365-2710
• DOI: 10.1111/jcpt.12829

Summary What is known and objective Treatment of tacrolimus toxicity includes holding tacrolimus and supportive care. The objective is to describe considerations for pharmacologic induction of tacrolimus metabolism. Case description A 52‐year‐old male with a failed renal transplant on chronic haemodialysis developed tacrolimus toxicity due to a drug‐drug interaction with darunavir/ritonavir. Tacrolimus concentrations were >60 ng/mL for 10 days despite holding tacrolimus and darunavir/ritonavir. Development of encephalopathy prompted initiation of phenytoin to induce tacrolimus metabolism. Tacrolimus concentration was <2 ng/mL within 4 days and mental status normalized. What is new and conclusion Phenytoin metabolic induction is a therapeutic option for prolonged tacrolimus toxicity. Tacrolimus toxicity lasting 10 days was successfully treated with phenytoin in this case report. Induction of tacrolimus metabolism is a viable option for treatment of toxicity and may have a quick onset.