INTERACTION BETWEEN TACROLIMUS AND ERYTHROMYCIN

A 40-year-old Asian man, 6 months post renal transplant and receiving tacrolimus therapy, presented to the emergency department with a compl aint of sudden-onset left eye pain with blurred vision, headache on th e left side, and nausea and vomiting. On being admitted, the patient w as intubated for respiratory depression, and erythromycin was initiate d for suspected atypical pneumonia. Tacrolimus concentrations (whole b lood) drawn on the 3rd day of hospitalization were reported to be > 60 .0 ng/ml. Before hospitalization, tacrolimus concentrations were repor ted to be 9.8 ng/ml on a maintenance dose of 7 mg twice daily. Six day s after discontinuation of erythromycin and a decrease in tacrolimus d ose, the concentration decreased to 11.5 ng/ml and the original dose o f tacrolimus was restarted, It is recommended that concurrent administ ration of erythromycin and tacrolimus be avoided. However, if concomit ant therapy is necessary, tacrolimus concentrations, serum creatinine, blood urea nitrogen, and urine output should be monitored.