Use of phenytoin for treatment of tacrolimus toxicity with superimposed sepsis

• Published in: BMJ case reports Vol. 13; no. 7; p. e234839
• Main Authors: Sharma, Aditi, Wahby, Krista A, Inany, Mohammed, Lee, Sarah J
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 20-07-2020; BMJ Publishing Group
• Series: Case report
• Subjects: Adult; Applied Basic Science; Ataxia; Case reports; Creatinine; Cytochrome P-450 CYP1A2 Inducers - therapeutic use; Drug dosages; Electrolytes; Enzymes; Female; Glucose; Humans; Hyperglycemia; Hypertension; Immunosuppressive Agents - therapeutic use; Infections; Kidneys; Kinases; Leukemia; Malnutrition; Metabolism; Muscle pain; Neurotoxicity; Ostomy; Phenytoin - therapeutic use; Proteins; Sepsis; Sepsis - chemically induced; Sepsis - drug therapy; Tacrolimus - adverse effects; Tacrolimus - blood; Tacrolimus - toxicity; Tracheotomy; Transplants & implants; Treatment Outcome; toxicology; acute renal failure; malignant disease and immunosuppression; adult intensive care
• ISSN: 1757-790X; 1757-790X
• DOI: 10.1136/bcr-2020-234839

A 40-year-old woman with a history of chronic graft-versus-host-disease on immunosuppression with tacrolimus presented to the hospital with somnolence, confusion and muscle cramps over a few days. She was found to have hypertension, hyperglycaemia and acute kidney injury with an elevated blood tacrolimus level of greater than 120 ng/mL (reference range 5–15 ng/mL). Discontinuation of tacrolimus with concomitant administration of intravenous phenytoin led to the successful reduction of elevated tacrolimus concentrations and the resolution of her symptoms. Tacrolimus is metabolised by the cytochrome P (CYP) 450 3A enzyme system, and utilisation of CYP 3A inducers to accelerate its clearance may be used as a successful therapy to treat tacrolimus toxicity.