Cyclosporine has some very serious long-term toxicity (especially renal dysfunction and hypertension) and the availability of newer biologic agents has restricted the use of cyclosporine to patients who have not responded to conventional treatment.

  *Mild tremor is common with both cyclosporine and tacrolimus use, occurring in 35 to 55 percent of patients [ 79,80 ].
  *Rarely, patients develop severe headache, visual abnormalities, and seizures. This syndrome is associated with acute hypertension and resembles hypertensive encephalopathy [ 77 ]. 
  *Posterior leukoencephalopathy is usually seen on brain imaging [ 82 ].
  *Cyclosporine may contribute to bone loss after organ transplantation [ 88 ]; this effect may be due to the induction of high bone turnover. 
  *Cyclosporine can cause hyperkalemia and hypomagnesemia, via effects on renal tubular function. Hyperuricemia and exacerbation of gout are well-described with cyclosporine.

[77]. Schwartz RB, Bravo SM, Klufas RA, et al. Cyclosporine neurotoxicity and its relationship to hypertensive encephalopathy: CT and MR findings in 16 cases. AJR Am J Roentgenol 1995; 165:627.

[78]. Eidelman BH, Abu-Elmagd K, Wilson J, et al. Neurologic complications of FK 506. Transplant Proc 1991; 23:3175.

[79]. Randomised trial comparing tacrolimus (FK506) and cyclosporin in prevention of liver allograft rejection. European FK506 Multicentre Liver Study Group. Lancet 1994; 344:423.

[80]. A comparison of tacrolimus (FK 506) and cyclosporine for immunosuppression in liver transplantation. The U.S. Multicenter FK506 Liver Study Group. N Engl J Med 1994; 331:1110.

[81]. Wijdicks EF, Wiesner RH, Krom RA. Neurotoxicity in liver transplant recipients with cyclosporine immunosuppression. Neurology 1995; 45:1962.