Pharm: Gout Flashcards
What are the 3 recommended potent NSAIDs for treating acute gout and the selectivity of each?
- Naproxen (non-selective)
- Indomethacin (COX 1 > COX 2)
- Celecoxib (COX-2, high dose, if others not tolerated)
Using NSAIDs for acute gout is most effective if treatment is initiated when?
≤48 hours of onset
If there are more than a couple joints involved by gout or NSAIDs and colchicine are contraindicated, which drugs can be used?
Glucocorticoids (betamethasone + methylprednisone + triamcinolone)
What is the MOA of Colchicine used for gout?
- DIffuses into cells to bind to tubulin, blocks formation of microtubules
- Leads to inhibition of leukocyte migration and phagocytosis
What are the clinical indications for using Colchicine for gout?
- Used in pt’s with NSAID intolerance or absolute contraindication to NSAIDs
- Small doses, prophylactically to prevent recurrence
Use of Colchicine for gout is contraindicated in whom?
Pt’s w/ advanced renal or hepatic impairment
What are the common toxicities of the gout drug, Colchicine?
GI distress, diarrhea, N/V
If pt with gout is an underexcreter with good GFR and no tophi or stones, which drugs can be used?
Urate lowering therapy w/ allopurinol, febuxostat or uricosuric agent
What is the MOA of Allopurinol?
- Metabolite acts as competitive inhibitor of xanthine oxidase
- W/o conversion to urate, hypoxanthine and xanthine are excreted
What is a noteworthy serious AE of Allopurinol?
Stevens-Johnson Syndrome (epidermal necrolysis) –> ↑ risk if HLA-B*5801
What is the MOA of Febuxostat used for gout?
- Non-purine inhibitor of xanthine oxidase –> blocks conversion to urate
- Hypoxanthine and xanthine are excreted
What is the clinical indication for using Febuxostat for gout?
Typically well-tolerated by those who cannot tolerate allopurinol
What is the MOA of the gout drug, Pegloticase?
- Recombinant mammalian uricase, covalently attached to methoxy polyethylene glycol –> prolongs ciruclating half-life and diminished immunogenic response
- Converts uric acid to the far more soluble allantoin
What is the clinical indication for using Pegloticase?
Tx of chronic gout in those refractory to conventional therapy
Which AE’s are associated with Pegloticase and how can they be managed?
- Infusion rxns i.e., fever, chills, rash, angioedema, bronchospasm, hypo- or HTN
- Need to premedicate w/ glucocorticoids and anti-histamines
What is the MOA of Probenecid and Sulfinpyrazone used for gout?
- Organic acid that acts at anionic transport sites of renal tubule in manner that blocks urate reabsorption more than urate secretion
- ↑ the fractional excretion of urate –> ↓ plasma [urate]
What is the clinical inidication for using Probenecid for gout?
- Used in underexcreters w/ GFR >60 mL/min and no stones to ↓ body pool of urate in pt’s with:
- Hyperuricemia
- Frequent attacks
- Tophi (?)… some say OK, others say no
Why is low-dose aspirin not a good choice for gout?
Aspirin promotes urate reabsorption
What are some of the AE’s associated with Probenecid and Sulfinpyrazone used for gout; strategies for minimizing these effects?
- Acutely ↑ risk of kidney stones (both uric acid and calcium oxalate) –> minimize by keeping well-hydrated and urine pH >6
- May cause gouty arthritis flare
- Sulfur-containing drug, may cause hypersensitivity
