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Flashcards in Immunosuppressants Deck (36)
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1
Q

Use of Immunosuppressants

A

Autoimmune disorders
Allograft rejection
Inflam disorders

2
Q

Rule of thumb of organ transplants

A

Use cocktail therapy

Induction - steroids
Maintenance - CNIs
Acute rejection - Steroids

3
Q

Most immunosuppresion strategies try to

A

Reduce or eliminate steroids

4
Q

Calcineurin inhibitors and mech of action

A

Cyclosporine, tacrolimus, pimecrolimus

Bind immunophilins

Cyclosporine binds cyclophin A to inhibt calcineurin

Other 2 bind FKBP-12 and inhibit calcineurin

5
Q

Calcinuein

A

Is a Ca2 dependent protein phosphatase….ubiquitous expression

6
Q

Mech of CNIs

A

inhibit calcineurin and prevent activation of NFAT…inhibits cytokine expression which prevents T and B cell activation…can;t really help with T cells that are alrwady activated

One effect is inhibition of IL-2

7
Q

CNI most common use, bioavailability, metabolics, adverse effects,

A

Prophylactic use
Variable bioavailability
Metabolized by CYP3A system in the liver
Extensive adverse effects

8
Q

CNIs in allograft transplant patients

A

Good at preventing acute rejection
Given orally at lowest dose that is effective
If dose is too high, then adverse effects
If too low, then risk of acute rejection
Don’t use until renal function stabilizes or improves

Only in maintenance phase

9
Q

CNIs and atopic dermititis

A

Topical CNI second line therapy to topical steroids

Used prophylactically

10
Q

CNIs advantage over topical steroids

A

CNIs show less absorption into bloodstream so fewer side effects
CNIs DO NOT retard development of mature immune response function

11
Q

Disadvantage of CNIs over topical steroids

A

CNIs are newer so no generics

Not a lot known about side efffect

12
Q

Pimecrolimus vs tracrolimus topical

A

Pimecrolimus shows less immunosuppression systemically than tacrolimus so preferred to use in young children or mild to moderate symptoms

13
Q

CNI side effects

A

Nephrotoxocity
PTDM (treat with insulin to combat)
Hypertension

14
Q

Nephrotoxicity of CNIs

A

Acute is most common and is reversible

Chronic can be irreversible

15
Q

CNI interactions

A

Durgs that inhibit CYP3A4 increase CNI levels and increased toxicity
Drugs that induce CYP3A4 decrease CNI and increase risk of rejection
Drugs that bind CNI and prevent absorption decrease CNI and increase risk of rejection

16
Q

Cytotoxic drugs

A

Azatthiprine and mycopheolate mofetil

Inhibit de novo purine synthesis

17
Q

AZ

A

Metabolite inhibits Glutamine PRPP amidotransferase that is rate limiting for converting PRPP to IMP

Also inhibits salvage pathway by methylating IMP

Makes it an antimetabolite

18
Q

MM

A

Inhibits IMP dehydrogenase that is rate limiting enzyme for converting IMP to GMP

Prefernetially inhibits IMPDH2 in lymphocytes

19
Q

Sirloimus

A

Binds to FKBP-12 and then binds to mTOR that is part of larger protein complex…mTOR normally positively regulate cells cycle so if inhibited, arrested in G1 phase

20
Q

Cytoxic drugs and allograft

A

Used during induction (MF preferred)
Maintenance used to lower or eliminate use of steroids or CNIs
Not used during acute rejection

21
Q

Azatioprine kinetics and metabolism

A

Incompletely absorbed…50% bioavail…metabolized in liver by XO and TPMT…excreted in urine

22
Q

MM kinetics and metabolism

A

Converted to MPA and absored rapidly and lamost completely
94% bioavail
Metabolized to MPAG bu glucuonyl transferase and exreted into urine and bile…Subject to enterohepatic recycling…2nd peak at 6-12 hours

23
Q

Sirolimus kinetics and metabolism

A

Similar to cyclosporine and tacrolimus

Incomplete absorption and metabolism by CYP3A4

24
Q

Adverse effect of Azathioprine

A

Risk of leukopenia (salvage path)

Mutation of TPMT can cause 6-MP toxicity

25
Q

MM adverse effets

A

Similar but less severe than azathiprine
Diarrhea by increases clearances of CNIs could lead to allograft rejection

Prefrred treatment option because of lower side effects

26
Q

Sirolimus adverse effects

A

Hypercholesterolemia

27
Q

Azathioprine drug interactions

A

Allopurinol is a XO inhibitor…Allopurinol will increase 6-MP levels

28
Q

MM drug interactions

A

Drugs that cause diarrhea

Acyclovir

29
Q

Sirolimus interactions

A

Slows down metabolism of CNIs which can exacerbate CI mediated toxicity

30
Q

Antithymocyte globulin

A

Polyclonal antibody

Bindsto T surface protein and depletes T and B cells

31
Q

Muromonab

A

Binds CD3 and leads to depletion of CD3 cells

Monoclonal

32
Q

Belatacept

A

Fusion between IgG1 and CTLA4
Immune checkpoint
CTLA4 binds CD80 and CD86 and suppresses activity of CD28
DO not use in EBV neg patients

33
Q

Basiliximab

A

Antibody to IL2 receptor alpha subunit….IL-2 important for clonal expansion…this drug inhibits IL2 receptor activation and therefore T cell proliferation

34
Q

Uses of antibody in allograft rejection

A

Anti-thymocyte globulin used in induction phase
Not used in maintenance except for belatecept
Mostly used for reversing of acute rejection (second line to steroids)

35
Q

Adverse effects of AB therapy

A

CRS (use pretreatment of steroids to prevent)
Posttransplant lymphoproliferative disorder (belatacept)…involves CNS..higher in EBV neg patients
Leukopenia - at risk of opportunistic infections
Thrombocytopneia

36
Q

Most common used AB therapy

A

Antithymocyte globulin has least side effects