15b - Renal Pharm 2 Flashcards
What are three types of immunosuppresives?
- Calcineurin inhibitors
- Interleukin blockade
- Cell cycle regulation of T cells
What are two calcineurin inhibitors and how does each work?
Cyclosporine: binds cytosolic receptor cyclophilin in order to block activation of calcineurin
Tacrolimus: binds cytosolic receptor FKBP12 to block activation of calcineurin
Both work to inhibit transcription of cytokines such as IL-2 that are essentual for T cell activation and proliferation
How is cyclosporine given? What is it metabolized by? What is its half life?
Oral or IV
Concentrates in tissues such as the liver, kidneys, spleen, and bone marrow.
Metabolized extensively by CYP3A4 in the liver.
Long half life (27 hours)
What are the side effects of cyclosporine?
- Nephrotoxicity
- HTN
- Tremor, headache, fatigue
- Hypertrichosis
- Gum hypertrophy (common)
- Hyperlipidemia, hypomagnesia, hypokalemia.
What drug interactions does cyclosporin have?
Interacts with nephrotoxic drugs such as NSAIDs, aminoglycosides, and antimicrobials.
Drugs that induce CYP3A4 - phenytoin, carbamazepine (cuts down half life)
Drugs that inhibit CYPP450 - erythromycin, ketoconazole (extends half life)
How is tacrolimus given? How is it metabolized? What are unwanted side effects?
Oral or IV.
Metabolized by the liver; highly variable half life (4-41 hours) and must monitor through blood concentration.
Side effects: pleural and pericardial effisions; mardiomyopathy in kids
What are side effects of calcineurin inhibitors?
- Hepatotoxicity
- CV: HTN and hypercholesterolemia
- Glucose intolerance
- Neurotoxicity (more with tacro)
What are drug interactions with calcineurin inhibitors?
- Nephrotoxic agents: NSAIDs, vanco, ganciclovir, aminoglycosides
- K-sparking diuretics
- Antacids
- Statins
What is the mechanism of action of Sirolimus?
Binds FKBP12 and the complex binds mTOR, elading to the inhibition of IL-2 induced cell cycle progression from G1 to S phase.
What is the metabolism of sirolimus? How is it given? What is the half life?
Oral
Gut absorption by P-glycoproteins
Metabolized by intestinal and liver CYP450.
Very long half life (60 hrs)
What are the side effects of sirolimus?
Edema, ascities, tachym, HTN
GI
Lyperlipidemia, hypokalemia, hypophosphatemia
Lymphocele - collection of lymph fluid
Rash
What drug interactions does sirolimus have?
Drugs that induce CYP3A4: rifampin
Drugs that inhibit CYP450: itraconazole and ketoconazole
What are the benefits of using sirolimus?
Potent prophylaxis against acute cellular rejection.
Less vasocontriction
Not associated with acute or chronic renal insufficiency: less interstitial fibrosis (down reulation of TGF-B and PDGF), sustained GFR
What is the mechanism of action of mycophenolate mofetil?
Competitive, reversible inhibitor of IMPDH, a rate-limiting enzyme in de novo purine synthesis
Lymphocytes depend on de novo synthesis (vs other cells that can use salvage)
Inhibits proliferation of B and T lymphocytes
How is mycophenolate mofetil given? How is it metabolized and what’s the half life?
Oral or IV
Metabolized in the liver
Long half life (18 hours)