Gout Flashcards
Gout
Inflammatory process in response to crystallization of monosodium urate in articular and non-articular tissues
Hyperuricemia: uric acid > 6.8 mg/dL
Epidemiology
Men are more likely to be affected by gout
Genetics
Dietary intake
Socioeconomic factors
Overproduction
regulatory enzyme variability
cytotoxic medications
increase dietary intake of purines
chronic alcohol intake
Underexcretion
Dehydration
Insulin resistance
Acute alcohol intake
Medications
Medications that can cause hyperuricemia
Diuretics
Cytotoxic drugs
Salicylates
Risk factors
Male
Post-menopausal women
Elderly
Obesity
Diet and alcohol intake
Sedentary lifestyle
Renal impairment
Presentation
Acute, inflammatory mono arthritis
Podagra: first metatarsal joint often involved
Uric acid can deposit elsewhere: fingers, wrist, cartilage, kidnets
Signs and symptoms
Fever
Intense pain
Erythema, warmth, edema, inflammation of the affected joints
Laboratory tests
Uric acid > 6.8 mg/dL
WBC > 11,000 cells/uL
Complications
Tophi: deposits of monosodium urate
Nephrolithiasis: kidney stones
Gouty nephropathy
General treatment approach
Treatment of pain and inflammation
Use of urate lowering therapy
Anti-inflammatory prophylaxis
Non-pharmacologic Therapy for acute attacks
Modify risk factors if able
Applying ice to the affected area
No supplement that shows benefit
Acute gouty attacks treatment
NSAID
Corticosteroids
Colchicine
NSAID adverse effects
GI bleeding
Kidney injury
CV effects
CNS effects
Corticosteroid formulations
Oral: medrol 4 mg dose pack, prednisone 0.5 mg/kg/day, tapered
IM: triamcinolone 60 mg x 1, methylprednisolone 100 mg x 1
Intra-articular: triamcinolone 10-40 mg (large joints), 5-20 (small joints)
If using IM/IA, follow with NSAID or PO corticosteroid
Corticosteroid considerations
Taper
Limit duration
Increase risk of GI bleed
Monitor DM
Avoid IA if infection is present
Colchicine
Administer within 24 hours of acute attack
Capsule, tablet, solution
DOSE:
Day 1: 1.2 mg PO once, then 0.6 mg one hour later
Day 2+: 0.6 mg BID until attack resolves
Colchicine side effects
N/V/D
Colchicine renal dose adjustments
CrCl < 30 mL/min
1.2 mg at onset, 0.6 mg 1 hour late (once)
Treatment course should be repeated no more than once every 2 weeks
Inadequate initial response
< 50% improvement in pain in 24 hours
Switch agents
Add a 2nd recommended agent: try to avoid NSAIDS with PO corticosteroids
Non-pharm for chronic management
Weight loss
DASH diet
Avoid foods high in saturated fats and sweetened beverages/food
Alcohol restriction
Limiting restriction of purine-rich foods
Indications for starting ULT
Frequent gout flare > or equal to 2 per year
> or equal to 1 tophus
Radiographic evidence
> 1 prior flare, but infrequent ( < 2 per year)
Patient experiencing first flare in the presence of 1 of the following: CKD stage 3-5, uric acid > 9 mg/dL
Who is not a candidate for ULT?
Asymptomatic hyperuricemia with no prior gout flares or tophi
First gout attack without risk factors
Xanthine oxidase inhibitors MOA
Reduces uric acid by impairing the ability of xanthine oxidase to convert hypoxanthine to xanthine and therefore uric acid
Allopurinol
Initial dose: 100 mg PO daily
Titrate every 2-4 weeks in < 100 mg increments as needed to achieve uric acid < 6
Febuxostat
Initial dose: 40 mg daily
Titrate to 80 mg daily if uric acid > 6 after 2 weeks
Allopurinol renal dose adjustments
CrCl < 60: initial dose
50 mg daily
Titrate slowly and in small increments, may consider doses > 300 mg with close monitoring
Allopurinol adverse reactions
rash
HA
hives
hepatotoxicity
hypersensitivity
Allopurinol hypersensitivity syndrome
Steven-Jonhson syndrome and toxic epidermal necrolysis
Risk factors:
Female
> 60 yo
High initial doses
CKD
CV disease
HLA-B* 5801 allele: Southeast Asian decent
Allopurinol monitoring
Uric acid every 2-5 weeks while titrating, every 6 months when stable
Renal function, LFTs
Allopurinol counseling
Drink plenty of fluids
Take this medication even when you do not have gout symptoms
Uricosuric Drugs MOA
Increase renal clearance of uric acid by inhibiting post-secretory renal proximal tubular reabsorption of uric acid
Probenecid
Initial dose: 250 mg PO BID x 1-2 weeks–>increase to 500 mg BID
Titrate by 500 mg increments every 1-2 weeks
Probenecid ADRs
Urolithiasis–>CI in patients with history
G6PD deficiency
Not recommended in eGFR < 60
Uricase Agents MOA
Recombinant form of urate-oxidase enzyme that converts uric acid to the more soluble metabolite, allantoin
Pegloticase
Used in SEVERE gout and hyperuricemia
> 3 gout flare within 18 months
1 tophi
Joint damage due to gout
IV infusion: 8 mg every 2 weeks
Pegloticase ADRs
BBW: anaphylaxis and infusion reactions, G6PD deficiency-associated hemolysis and methemoglobinemia
Pegloticase when to use
Patients who have failed xanthine oxidase inhibitors, uricosurics who continue to have gout flares
Patients with non-resolving tophi
Gout attack prophylaxis
Use when initiating ULT
Goal is to decrease attacks
First 3-6 months
Agents for prophylaxis
NSAIDS at the lowest effective dose
Prednisone < 10 mg/day
Colchicine: CrCl < 30–> 0.3 mg daily
