Table 2 Maintenance immunosuppressive drugs

Corticosteroids

Increased bioavailability with hypoalbuminaemia and liver disease.

Cytosolic receptors. Heat shock proteins.

Blocks transcription of cytokine genes (eg IL-1, IL-2, IL-3, TNF-α, and IFN-γ).

Hypertension, glucose intolerance, dyslipidemia, osteoporosis.

Cyclosporine

Lipid soluble, poor/variable oral absorption. Neoral has improved and more predictable bioavailability.

Binds cyclophylin. Inhibits calcineurin.

Inhibits IL-2 production. Stimulates TGF-β production.

Nephrotoxic effects, hypertension, dyslipidemia, glucose intolerance.

Tacrolimus (FK506)

Better oral bioavailability than cyclosporin standard form

Binds FKBP-12. Inhibits calcineurin.

Inhibits IL-2 production. Antagonizes TGF-β.

Similar to cyclosporine but less hirsutism/gum enlargement. Up to 20% incidence of IDDM.

Hepatic metabolism.

Azathioprine

Hepatic metabolism to active product.

Metabolites bind DNA.

Inhibits purine synthesis, Blocks DNA and RNA synthesis.

Marrow suppression.

MMF

Good bioavailability. Hepatic metabolism to form active product.

Inhibits inosine monophosphate dehydrogenase.

Blocks de novo pathway of purine synthesis (selective for lymphocytes). Blocks glycosylation.

Diarrhea/gastrointestinal upset. Cytomegalovirus. Increased but no reported. cases of PCP.

Sirolimus

Lipid soluble. Poor oral bioavailability.

Binds FKBP-12. Blocks p70 S6 kinase.

Blocks IL-2-induced cell cycle. progression.

Hyperlipidemia. Thrombocytopenia.