Immunosuppressants Flashcards
Major classes of immunosuppressants
- Corticosteroids
- Cyclophilin-binding drugs
- Immunosuppressant anti-metabolites
- Antibodies
Most important clinical corticosteroids
- Methylprednisone
- Presdnisolone
- Prednisone
Effects of corticosteroids in various tissues
Complications of chronic corticosteroid use
- Bone loss
- Peptic ulcers
- Hypertension
- Infection
- Increased blood glucose
- Osteonecrosis
- Weight gain
- Cataracts
- Striae (stretch marks)
- Muscle atrophy
The hypothalamic-pituitary-adrenal axis
The cyclophilin binding drugs
- Cyclosproine & Tacrolimus: Bind NF-AT
- Sirolimus (Rapamycin) & Everolimus: Bind mTOR
- Both groups serve to impede T cell growth, activation, and mediator production
When do we use cyclophilin binding drugs?
- Most importantly, FOR TRANSPLANTS to prevent rejection
- Also, to treat T cell-mediated diseases: Psoriasis, RA, Crohn’s, atopic dermatitis
Cyclosporine A mechansitic diagram
Complications and toxicities of cyclosporine
- Infection (obviously)
- Cancer (obviously)
- Hypertension
- Renal toxicity
- Hepatic toxicity
- Tremor
Tacrolimus (aka FK506) mechanistic diagram
mTOR
Member of the phosphatidylinositol 3- kinase-related kinase protein family;
it is a serine/threonine protein kinase that regulates cell growth, cell proliferation, cell motility, cell survival, protein synthesis, autophagy, transcription
TCR and IL-2R pathways
Immunosuppressive antimetabolites
- Inhibit cell replication and thus affect immune system because it has the most rapidly dividing natural human cells
- Methotrexate
- Mycophenylate
- Azathioprine
Methotrexate
- First line therapy for RA
- Dose dependent liver fibrosis is a toxicity
- Incompatible with pregnancy
- An antifolate
Azathioprine
- Pro-drug which is converted into 6-mercaptopurine then into thioinosinic acid once inside of cell
- Thioinosinic acid inhibits DNA synthesis
Mycophenylate
- Converted into mycophenylic acid
- Inhibits inosine monophosphate dehydrogenase, an ezyme involved in nucleotide biosynthesis
- Fairly selective action at inhibiting T and B cell proliferation