Overview of Gout and It's Treatment

Overview of Gout

• Gout: A form of inflammatory arthritis due to deposition of monosodium urate crystals.
• Cause: Hyperuricemia (serum uric acid > 6.8 mg/dL)
• Management goals:
• Terminate acute attacks
• Prevent future attacks
• Lower serum uric acid levels

Classification of Anti-Gout Drugs

1. Acute Attack Treatment:
• Colchicine
• NSAIDs
• Corticosteroids
2. Chronic Management:
• Uricostatic agents (e.g., Allopurinol, Febuxostat)
• Uricosuric agents (e.g., Probenecid, Sulfinpyrazone)

Allopurinol

• Class: Xanthine oxidase inhibitor
• Mechanism of Action:
• Inhibits xanthine oxidase enzyme
• Decreases production of uric acid
• Indications:
• Chronic gout
• Prevention of uric acid nephropathy
• Tumor lysis syndrome
• Adverse Effects:
• Rash (can be severe - SJS)
• GI upset
• Hepatotoxicity
• Hypersensitivity syndrome
• Drug Interactions:
• Increases effect of azathioprine and 6-mercaptopurine
• Requires dose reduction with these drugs

Febuxostat

• Class: Selective xanthine oxidase inhibitor
• Mechanism of Action:
• Non-purine selective inhibitor of xanthine oxidase
• Reduces serum uric acid
• Indications:
• Chronic hyperuricemia in gout
• Adverse Effects:
• Liver function abnormalities
• Cardiovascular events (boxed warning)
• Rash, nausea
• Drug Interactions:
• Same as allopurinol (azathioprine, mercaptopurine)

Colchicine

• Class: Microtubule inhibitor
• Mechanism of Action:
• Binds tubulin, inhibits neutrophil motility and activity
• Reduces inflammation in gouty arthritis
• Indications:
• Acute gout attacks
• Gout prophylaxis
• Adverse Effects:
• GI upset (diarrhea, nausea, vomiting)
• Myopathy and neuropathy (especially with renal impairment)
• Bone marrow suppression (rare)
• Drug Interactions:
• CYP3A4 and P-gp inhibitors (e.g., clarithromycin, cyclosporine) increase toxicity

Probenecid

• Class: Uricosuric agent
• Mechanism of Action:
• Inhibits reabsorption of uric acid in renal tubules
• Increases urinary excretion of uric acid
• Indications:
• Chronic gout (underexcreters of uric acid)
• Adverse Effects:
• Uric acid kidney stones
• GI irritation
• Rash
• Drug Interactions:
• Inhibits excretion of many drugs (penicillin, NSAIDs)
• Increases risk of toxicity

Sulfinpyrazone

• Class: Uricosuric agent
• Mechanism of Action:
• Similar to probenecid
• Promotes renal excretion of uric acid
• Indications:
• Chronic gout
• Adverse Effects:
• GI irritation
• Rash
• Agranulocytosis (rare)
• Drug Interactions:
• Displaces other drugs from plasma proteins
• Inhibits metabolism of warfarin

Presentation for Drugs for Gout 

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