PBL Pharmacology

Question 1

How should you treat uncomplicated HSP?

Answer 1

Supportive care

Question 2

When should you treat HSP with drugs (ex: steroids)?

Answer 2

When crescents are found on renal biopsy –> indicates crescentic glomerulonephritis

Question 3

What is the top treatment for crescenteric HSP?

Answer 3

High dose steroids + cyclophosphamide or daily mycophenolate mofetil

Question 4

What corticosteroid is usually used for HSP?

Answer 4

Prednisone

Question 5

What drug is Azathioprine similar to?

Answer 5

6-Mercaptopurine

Question 6

What is the MOA for Azathioprine?

Answer 6

Active metabolite (methyl-thioinosine monophosphate - MeTIMP) is a purine synthesis inhibitor that works by blocking the enzyme amidophosphoribosyl transferase –> functions as immunosuppressive agent

Question 7

What is the MOA for Cyclophosphamide?

Answer 7

• 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

Question 8

What is the mechanism of acetaminophen?

Answer 8

• Weak, reversible, non-specific COX inhibitor
• Doesn’t inhibit platelets
• Antipyritic, Analgesic
• CNS inhibition of prostaglandin synthetase –> dec. PGE2
• Possible inhibition of COX-3

Question 9

What is the MOA of Mycophenolate Mofetil?

Answer 9

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

Question 10

How does Mycophenolate Mofetil specifically target T and B cells?

Answer 10

Other cells use the salvage pathways to make purines and are thus more able to escape the effect

Question 11

What is the MOA for steroids?

Answer 11

• Stabilizes neutrophil lysozymes
• Lipocortin inhibits phospholipase A2 which inhibits prostaglandins and lipoxygenases
• Glucocorticoid receptors (in membrane) –> GRE (nucleus) –> Inc. transcription of anti-inflammatory genes

Question 12

What two OTC drugs can lead to renal damage?

Answer 12

• Aspirin

- Ibuprofen

Question 13

How does Prednisone work?

Answer 13

Corticosteroid

• Blocks glucocorticoid receptor
• Interacts with SRE –> inhibits many cytokines and proteins (including phospholipase A2 and COX)
• Immune suppression (may raise WBC though)