gout Flashcards
pathophysiology of gout
- imbalances in purine metabolism
- deposition of monosodium urate crystals in articular and periarticular tissues
lifestyle risk factors
alcohol consumption
sugary beverages
red meat
sedentary lifestyle/obesity
males (gender narrows after menopause)
drugs decreasing uric acid clearance
Diuretics (thiazides, loop diuretics)
Low dose salicylates
Ethambutol
Pyrazinamide
Levodopa
diet induced purine/urate overproduction
excess ethanol, dietary purine, fructose, cytotoxic drugs
examples of purine rich foods (name 3)
anchovies, asparagus, mushrooms, red meat, peanuts, durian, organ meat, cockles, mussels
confirmatory diagnosis for gout
presence of uric acid crystals in joint aspirate
treatment goals of gout
safe, effective pain relief
reduce future attacks
prevent joint destruction and tophi formation
increase qol
avoid concurrent nsaids with…
steroids
colchicine dosage for acute flare
1mg LD + 0.5mg 1hr later
or
0.5mg BD/TDS until acute flare resolves
colchicine main AE
gi
non pharm for gout
topical ice, max 15 mins, do not put directly over
alternative to nsaids/colchicine
intra-articular/IM corticosteroids
treatment target for non-tophaceous gout
< 360 µmol/L (6mg/dL)
when to initiate ult
- at least two gout flares per year
- presence of tophus
- clinical or imaging findings of gouty arthropathy
- urolithiasis hx
clinical remission means
no flares for ≥1 year and no tophi
colchicine moa
Anti-mitotic;
Binds to tubulin, prevents polymerisation into microtubules
Inhibits leukocyte migration and phagocytosis
Inhibiting leukotriene B4 and PG production
precautions of colchicine
renal impairment (especially when paired with NSAIDs)
colchicine metabolism and common ddi
cyp3a4
statins, azoles, macrolides
colchicine ci
crcl<30ml/min
colchicine adverse reactions
GI (NVD), ab pain, muscle weakness, unusual bleeding
allopurinol and febuxostat moa
Xanthine Oxidase inhibitors, prevent production of uric acid
initiation dose of allo
maximum 100 mg/d
how to titrate allo
50 to 100 mg every 2-8 weeks
maintenance dose of allo
at least 300 mg/d
what drugs with allo can increase bone marrow suppression?
6 mercaptopurine
Azathioprine
Cyclophosphamide
what drugs with allo can increase toxicity of allo?
ACEi
Loop/thiazides
Ampicillin
Amoxicillin
allopurinol / febuxostat AE
Risk of SCAR (Allo>Feb)
NVD, fever, sore throat, dark urine, jaundice
Higher risk of death in patients with gout and major CVS (Feb>Allo)
sjs ten symptoms
Fever, lesions leading to necrosis and sloughing of epidermis
dress symptoms
Fever, rash, multiorgan failure
gene involved with increased scar risk
hlab*-5801(Han Chinese, Thai, Korean)
other clinically significant ddi
CBZ, Warfarin, Theophylline (increased concentration)
initiation of ULT should be accompanied by? and what doses?
Anti-inflammatory prophylaxis for 3-6 months
Colchicine 0.5mg OD
PO Celecoxib 200 mg OD
PO Prednisolone 5-7.5 mg OD
febuxostat how to initiate
max 40mg/d
titrate febuxo
up to 80mg/d if target not met after 2-4 weeks
febuxostat metab
liver
febuxo caution in
hf/chd
probenecid moa
Uricosuric agents.URAT1 [& GLUT9 inhibitor. Inhibit proximal tubule anion transport and uric acid reabsorption.
initiate probenecid
250mg BD x 1wk then 500mg BD
titrate probenecid
500 mg/mth
maintain probenecid
≤2 g/d
probenecid ci
Urolithiasis
CrCl <50ml/min (ESRF)
probenecid ae
NV, painful urination, rash, lower back pain
haemolytic anemia (pts with g6pd)
probenecid admin instructions
hydrate at least 2L a day to prevent formation of kidney stones
ensure urine pH >6 by administering alkaline
are opioids preferred for gout/ra/oa
not anti-inflammatory
opioids ae
gi (nv, constipation)
hormonal effects
depression
respiratory effects
overdose and death
fractures
sedation
tolerance, addiction
opioid-induced hyperalgesia
precautions for opioids
cns depressants, renal/hepatic insufficiency, >65 yo, pregnancy, hx of substance use disorder
