Management of Tacrolimus in Cardiac Transplant Patients with Infectious Diarrhea

Introduction to Tacrolimus Management

• The American College of Cardiology recommends maintaining prednisona at basal dose to prevent rejection during the adjustment period in cardiac transplant patients with infectious diarrhea 1

Diagnostic Considerations

• The Infectious Diseases Society of America suggests that before attributing diarrhea solely to infection, one must rule out direct toxicity from tacrolimus, which can cause diarrhea as an adverse effect, with levels potentially elevated 2
• The American Gastroenterological Association recommends performing coproculture, PCR for norovirus, rotavirus, CMV, and parasites to diagnose specific infections in patients with diarrhea 3

Pharmacological Interactions

• The Clinical Infectious Diseases guidelines advise that azole antifungals (fluconazol, voriconazol) inhibit CYP3A4 and will further increase tacrolimus levels; thus, the dose of tacrolimus should be reduced by 50-75% prophylactically 1, 2
• The Chest journal recommends that macrolides (erythromycin, clarithromycin) have the same effect, and azithromycin should be preferred if a macrolide is required 2

Monitoring and Adjustment

• The Clinical Infectious Diseases guidelines suggest monitoring tacrolimus levels every 2-3 days when starting any antimicrobial agent 1, 2