Lecture 7.1 - Gout 2 Flashcards
Allopurinol Hypersensitivity Syndrome Manifestation
Rash, chills, fever, leukopenia, leukocytosis, eosinophilia, and pruritus
Maybe severe and fatal ( hepatotoxicity, vasculitis, SJS and TEN)
AHS prevention
HLA-B*5801 screening
only in high risk, and those who are positive we won’t use allopurinol
AHS management
Discontinue allopurinol at 1st sign of rash
Supportive care
AHS mortality rate
~ 25%
Rare tho
Allopurinol CI
Allopurinol sensitivity
concurrent didanosine use
Allopurinol DI
Didanosine
Azathioprine + 6-mercaptourine (MUST reduce dose of both when used in combo with Allopurinol)
Theophylline
Pegloticase
Loop/thiazide diuretics
Allopurinol monitoring
Efficacy: SUA every few weeks till goal
Safety: HLA-B*5801 test prior to start in high risk pops
High risk pops for HLA-B*5801
Han chinese
Korean
Thai
AA
Allopurinol patient education
Signs and symptoms of allergic reaction
HLA testing
How to use
Febuxostat (Uric) MOA
non-purine inhib of XAI leading to reduced production of uric acid
Febuxostat ADR
Hepatic: abnormal LFTs
GI: nausea
Rheumatologic: Gout flares
Rash, Arthralgia
Febuxostat CI
concomitant use of Azathioprine or 6-mercaptopurine
Febuxostat Precuations
Acute gout flare
CVD events
Hepatoxicity
Serious skin reactions
Febuxostat DI
Azathioprine or 6-mercaptourine
Theophylline
pegloticase
didanosine
Febuxostat Monitoring
Efficacy: SUA after 2 weeks of treatment + periodically
Safety: LFTs at BL and if signs of hepatic injury
Febuxostat Pt education
use
ADR
dont use with azathioprine or 6-MP
Study that chose Allopurinol > Febuxostat in CV patients?
CARES Trial
Febuxastat as Black Box warning due to study
Uricosurics
Probenecid
Sulfinpyrzone
Benzbromerone
Losartan
Probenecid MOA (Benamid)
Competitively inhibits the postsecretory renal proximal tubular reabsorption of uric acid
When to avoid Probenecid?
CrCl < 50
Probenecid SE
Most common = GI, uric acid nephrolithiasis (Uric Acid kidney stones)
Hemolytic Anemia (in G6PD deficiency in Mediterranean & AA)
Probenecid CI
HX of urolithiasis Overproducer of uric acid Hypersensitivity to it Small & Large dose salicylate therapy Blood dyscrasias < 2 yrs old initiation during acute gout attack
Probenecid Precautions
Disease related: G6PD, PUD, Renal impairment
Drug-related: Methotrexate, penicillin, salicylate
Probenecid DI
Salicylates
Penicillins/Cephalosporins/Carbapenems
Methotrexate
Pegloticase