Ciclosporin is an immunosuppressant widely used to prevent transplant rejection.

Mechanism of action

Decreases clonal proliferation of T cells by reducing IL-2 release. It acts by binding to cyclophilin forming a complex which inhibits calcineurin, a phosphatase that activates various transcription factors in T cells


  • Following organ transplantation
  • Rheumatoid arthritis
  • Psoriasis (has a direct effect on keratinocytes as well as modulating T cell function)
  • Ulcerative colitis
  • Pure red cell aplasia

Adverse effects

Adverse effects of ciclosporin (note how everything is increased - fluid, BP, K+, hair, gums, glucose)
  • Nephrotoxicity
  • Hepatotoxicity
  • Fluid retention
  • Hypertension
  • Hyperkalaemia
  • Hypertrichosis
  • Gingival hyperplasia
  • Tremor
  • Impaired glucose tolerance
  • Hyperlipidaemia
  • Increased susceptibility to severe infection

Interestingly for an immunosuppressant, ciclosporin is noted by the BNF to be 'virtually non-myelotoxic'.