PBL Pharmacology Flashcards
How should you treat uncomplicated HSP?
Supportive care
When should you treat HSP with drugs (ex: steroids)?
When crescents are found on renal biopsy –> indicates crescentic glomerulonephritis
What is the top treatment for crescenteric HSP?
High dose steroids + cyclophosphamide or daily mycophenolate mofetil
What corticosteroid is usually used for HSP?
Prednisone
What drug is Azathioprine similar to?
6-Mercaptopurine
What is the MOA for Azathioprine?
Active metabolite (methyl-thioinosine monophosphate - MeTIMP) is a purine synthesis inhibitor that works by blocking the enzyme amidophosphoribosyl transferase –> functions as immunosuppressive agent
What is the MOA for Cyclophosphamide?
- Immunosuppressive agent
- Alkylating agent, may cross-link DNA –> interfering with DNA replication and transcription of RNA –> disrupts nucleic acid function
- Active metabolites interfere with rapidly proliferating malignant cells
What is the mechanism of acetaminophen?
- Weak, reversible, non-specific COX inhibitor
- Doesn’t inhibit platelets
- Antipyritic, Analgesic
- CNS inhibition of prostaglandin synthetase –> dec. PGE2
- Possible inhibition of COX-3
What is the MOA of Mycophenolate Mofetil?
Reversibly inhibits inosine monophosphate dehydrogenase (enzyme that controls rate of synthesis of guanine monophosphate in the de novo pathway of purine synthesis –> used in proliferation of B and T lymphocytes)
-Inhibits T and B cells –> also inhibits antibody formation by B cells
How does Mycophenolate Mofetil specifically target T and B cells?
Other cells use the salvage pathways to make purines and are thus more able to escape the effect
What is the MOA for steroids?
- Stabilizes neutrophil lysozymes
- Lipocortin inhibits phospholipase A2 which inhibits prostaglandins and lipoxygenases
- Glucocorticoid receptors (in membrane) –> GRE (nucleus) –> Inc. transcription of anti-inflammatory genes
What two OTC drugs can lead to renal damage?
- Aspirin
- Ibuprofen
How does Prednisone work?
Corticosteroid
- Blocks glucocorticoid receptor
- Interacts with SRE –> inhibits many cytokines and proteins (including phospholipase A2 and COX)
- Immune suppression (may raise WBC though)