Immunosuppresants

Question 1

Azathioprine

Answer 1

Inhibits lymphocyte proliferation by blocking nucleotide syn
Metabolized by XO, fatal DI with allopurinol
SE: myelosuppression

Question 2

Methotrexate

Answer 2

Inhibits dihydrofolate reductase, interferes with purine and pyrimidine syn
Antidote: folinic acid

Question 3

Mycophenolate mofetil

Answer 3

Inhibits type II inosine monophosphate dehydrogenase
Catalyze rate limiting step in guanosine formation
Guanosine dec, adenosine inc
AE: GI effects, pancytopenia

Question 4

Leflunomide

Answer 4

Inhibits pyrimidine syn -> results in dec lymphocyte activation

Question 5

Cyclophosphamide

Answer 5

Highly toxic
Risk of bladder cancer
Produces carcinogenic metabolite that concentrates in urine
Can be neutralized by mesna

Question 6

Xanthine Oxidase inhibitors

Answer 6

Block formation of uric acid and breakdown of toxic drug to nontoxic metabolite

Question 7

Cyclosporine

Answer 7

Inhibits IL2, IL3, IFNgamma, T cell fxn

Nephrotoxicity

Question 8

Tacrolimus

Answer 8

Inhibits calcineurin
More potent than cyclosporine
Metabolized by CYP450
Nephrotoxicity

Question 9

Sirolimus

Answer 9

mTOR inhibitor
Bind FK binding protein -> complex that blocks molecular target of rapamycin
Profound myelosuppression
NOT nephrotoxic and can be used in kidney transplants

Question 10

TNF alpha inhibitors

Answer 10

Etanercept: TNF receptor analog
Infliximab: antiTNF alpha Ab

Question 11

Anakinra

Answer 11

IL1 antagonist

AE: neutropenia, risk of infection, ax to E. coli

Question 12

Rituximab

Answer 12

Anti CD20 Ab

Inhibits B cell by binding to CD20 and depletes B cells used in RA and CD20 + lymphomas