Pharmacotherapy of Gout
- 2. CLASSIFICATION In acute gout • Colchicine • NSAIDs In chronic gout • 1. Uric acid synthesis inhibitors- • Allopurinol • Febuxostat • 2. Uricosuric drugs- • Probenecid • Sulphinpyrazone • Benzbromarone
- 3. • Gout- metabolic disorder, high levels of uric acid in blood • Leads to deposition of uric acid crystals in tissues, joints, kidney. • Therapeutic strategies- lowering uric acid levels below saturation point- 6mg/ml
- 4. 1. COLCHICINE TREATMENT OF ACUTE GOUT •Alkaloid obtained from Colchicum •Highly effective in treatment of acute gouty arthritis
- 7. DRUG INTERACTIONS • Cimetidine and Erythromycin reduces metabolism of Colchicine and increases its toxicity
- 8. THERAPEUTIC USES • Orally, 2 doses of 1.2mg, foll by .6mg hr later • Relieves pain 24-48hrs later Treatment of acute attacks of gouty arthritis • Prophylactically- 0.6mg twice daily • Reduces frequency of attacks in pts having 3 or more attacks a year Prevention of acute attacks of gouty arthritis
- 9. 2. INDOMETHACIN Dose- 25-50mg tid for 5-7 days- relieves pain Gastric intolerance-high Alternatives- Naproxen, Sulindac, Ibuprofen
- 10. 3. GLUCOCORTICOIDS • Very severe cases • Action- not specific • Prednisolone- 30-40mg first day, reduced by 5- 10mg every day
- 11. • Reduce plasma urate levels • Do not prevent acute attacks • Diminish incidence of renal damage • Therapy started only after subsidence of acute attacks as it may delay recovery • But pre existing therapy should not be stopped in case of acute attack LONG TERM TREATMENT OF GOUT
- 12. I. URICOSURIC DRUGS A. PROBENECID • Orally, initial dose- 0.5g once daily, increasing to 3 times daily • Small dose- decrease distal tubule secretion of uric acid • Large dose- increase excretion, blocks reabsorption • ADR- Well tolerated, dyspepsia, skin rashes
- 13. DRUG INTERACTIONS • Inhibits renal excretion of Penicillin, Indomethacin, Dapsone • Impairs heparin metabolism • 0.5-1g OD • BENCID 500mg tab DOSE
- 14. B. SULPHINPYRAZONE • Actions, ADR- Same as Probenecid • Once/Twice daily • Chronic gout- 200mg/day, increased to 400- 800mg/day • ANTURAN 100, 200 mg tab C. BENZBROMARONE • Inhibits tubular reabsorption of uric acid • 40-80mg once daily • Comb with allopurinol
- 15. II. XANTHINE OXIDASE INHIBITORS A. ALLOPURINOL •Analogue of hypoxanthine •Inhibits biosynthesis of uric acid PHARMACOKINETICS •80% absorbed orally •T1/2- 2-3 hr
- 17. ADR GI irritation Nausea Headache Hypersensitivity reactions- Rashes
- 18. DRUG INTERACTIONS • Anti cancer drugs- 6-mercaptopurine, Azathioprine are metabolized by xanthine oxidase • So, dose of anti cancer drugs should be reduced when Allopurinol is used • Initial dose- 100mg/day, increased to 300mg/day • Tophi resorbed, renal stones prevented • ALORIC, ALURID, CIPLORIC 100,300mg tab USES
- 19. B. FEBUXOSTAT • Reduces formation of xanthine an uric acid • ADR- gout flares, nausea, diarrhoea • Dose- 80-120mg
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