Immunosuppressive for transplantation

Ciclosporin and Tacrolimus
- Both are calcineurin inhibitors, inhibit T cell activation
- ciclosporin forms complexes with cyclophilin whereas tacrolimus binds with immunophilin FK binding protein-12
- both used as rescue agent for treating rejection and  as maintenance agent
- levels of both drugs need to be monitored carefully
- both metabolised by cytochrome P450 3A enzyme
- DO NOT cause myelosuppression

Azathioprine
- purine analogue metabolised to mercaptopurine
- prevent cell mediated rejection by blocking purine synthesis
- converted to inactive metabolite by xanthine oxidase (thus, CANNOT give allopurinol!)
- check TPMT (thiopurine methyltransferase) level before initiate treament
- side effects: bone marrow suppression, pancreatitis

Mycophenolate mofetil
- nucleotide inhibitor
- inhibits IMPD (inositol monophosphate dehydrogenase)
- specific for lymphocytes because unlike other cells, an alternative purine synthetic salvage pathway is absent in lymphocytes
- side effects: mostly GI upset, also pancytopenia

Antibodies
- polyclonal : anti-thymocytic globulin (ATG) and anti-lymphocytic globulin (ALG)
- monoclonal : OKT3