Gout Flashcards
Pathophysiology of Gout
Abnormal deposit of urate in joints (can also impact kidneys as well)
What are key diagnostic features of gout?
- Male
- Use of gout-inducing medications
- Consumption of high-purine food
- Hx of medical conditions with high rate of cell turnover
- Rapid onset of pain
- Joint stiffness
- Foot-joint distribution
- Swelling, erythema, pain
- Tophi
What foods and beverages can precipitate gout?
High-purine foods and beverages:
- Organ meat
- seafood
- Sweetened Beverages
- Fructose
- Ethanol
- Beer
What medication can cause gout?
Thiazide and loop diuretics
Cyclosporins
Aspirin
What is Tophi?
Nodules created by monosodium urate crystals in a matrix of lipids, proteins, and monopolysaccharides
What is the uremic goal for a normal person?
< 6 mg/dL and to decrease attacks
What is the uremic goal for a person with increased risk factors?
<5 mg/dL
What joint is most often affected?
Big toe
What is the normal short-term treatment approach?
NSAIDs
Antigout drugs
corticosteroids
How do NSAIDs aid in gout treatment?
Inflammatory response:
• Urate crystal formation in the joint space –> destruction of the cell membrane –> release of chemical mediators by enzymes –> inflammation
Indomethacin:
MOA
Dose
Precautions/Cautions
Indomethacin: MOA: Anti-inflammatory Dose: 50 mg PO TID Precautions/Cautions: -- Take with food -- Same precautions as other NSAIDs --Caution with depression/psychiatric disorders
Allopurinol MOA
Dosing
Acts directly on purine metabolism
Allopurinol:start100mgQD,increaseby100 mg/day qwk until uric acid level <6 mg/dL; max 800 mg QD (for doses >300 mg divide BID–QID); give with food
Febuxostat (Uloric) MOA:
Dosing
Potent and selective inhibitor of xanthine oxidase –> reduces the formation of xanthine and uric acid
Febuxostat(Uloric):start40mgQD,may increase to 80 mg QD if uric acid level >6 mg/dL after 2 weeks (can take with NSAID or colchicine with flare)
Colchicine (Colcrys) MOA:
Dosing
Decreases deposition of uric acid and reduces phagocytesà decreased inflammation
• Metabolized in liver and excreted in kidneys
Colchicine(Colcrys):start1.2mgPOx1,then0.6 mg 1 hr later x 1; max 1.8 mg total dose/attack
Allopurinol Side Effects
Diarrhea N/V Abdominal pain Rash Pruritis Elevated ALT/AST, ALK, PHOS
*Rare: Aplastic anemia, hepatic toxicity, bone marrow suppression
Febuxostat Side Effects
Diarrhea N/V Abdominal pain Elevated ALT/AST Headache
*Rare: hepatic toxicity, Steven Johnson syndrome, Rabdo, Interstitial nephritis
Colchicine Side Effects
Diarrhea
N/V
Cramping/Abdominal pain
*Rare: Hepatic necrosis, Acute renal failure, DIC, Death
What are some cautions with anti-gout drugs?
Caution with (severe) renal and hepatic impairment
What drug are some drug interaction to be concerned about when prescribing Allopurinol?
Allopurinol inhibits probenecid and Anticoagulants.
Allopurinol increases hepatic iron concentrations
What labs need to monitored with Allopurinol?
Baseline and Monitor LFT’s
Test those of Asian descent for HLA-B5801 allele before starting
What kind of medication is Probenecid?
Uricosuric agent
Probenecid MOA
Increases renal excretion of uric acid and decreases serum uric acid levels
Is probenecid used for acute attacks?
NO, initiate 2-3 weeks after acute attack
Probenecid Side Effects
Nausea/vomiting Rash and pruritus Headache Fever Nephrotic syndrome *Aplastic or hemolytic anemia *Hepatic necrosis
Probenecid Contraindication/cautions
Underlying or recent h/o PUD Uric Acid Nephrolithiasis Acute gout attack CrCl <50 Avoid ASA or Salicylates --> Mutually antagonistic with Probenecid Sulfa --> allergy/sensitivity
Probenecid Dosage
Probenecid: start 250 mg PO BID x 7 days;
max 2–3 g/day
(CrCl <50 ineffective; avoid use with PCN when known renal impairment)
Take with food
What pregnancy Category is Probenecid?
Category B
Unknown in lactation
What pregnancy Category is Allopurinol?
Category C
Found in breast milk
What pregnancy Category is Colchicine (orally)
Category C
Unknown in lactation
What pregnancy Category is Febuxostat
Category C
Unknown in lactation
What pregnancy Category is Colchicine (parenterally)
Category D
What should be used in patients with renal calculi?
Allopurinol
What monitoring should be completed with anti-gout and uricosuric agents?
• Monitoring
– Serum uric acid levels
Men <7 mg/dL; Premenopausal woman <6 mg/dL
Every 2-5 weeks initially, every 6 months once
stable
– LFTs,
--BUN/Cr with allopurinol
– CBC with probenecidHow should acute attacks be managed?
Continue prophylactic med with addition of colchicine
What signs and symptoms should a patient stop taking the med call provider?
A sore throat, fatigue, jaundice, unusual bruising/bleeding, muscle weakness/pain
What lifestyle modifications can patients make to reduce gout attacks?
Lifestyle management: low-purine diet, low Na+, low Ca+, low ETOH, >3 liters/day of fluids
How are corticosteroids used in gout attacks?
- Used for acute flares
- Burst or flare
- Same s/e profile and considerations when used in RA
