Tacrolimus may be superior to cyclosporine in liver transplantation and is being in many centers. The ED physician who may encounter transplant patients should be familiar with these agents. An overview of the common immunosuppressant drugs follows. Cyclosporine achieves its effects through reversible inhibition of immunocompetent lymphocytes in the G0 and G1 phase of cell division. Cyclosporine also inhibits lymphokine production and release, including interleukin-2.
Elimination is primarily biliary, with excretion into the urine.
Cyclosporine is dosed according to blood levels and renal function. The dose is highly individualized, due to variable absorption, elimination, and effect on renal function. Principal toxicity of cyclosporine is nephrotoxicity manifested acutely by elevations in BUN and creatinine. This toxicity usually is reversible with reductions in dosage. However, an irreversible form is associated with histologic changes in the kidney.