Gout Flashcards
What is gout?
It is defined as a crystal arthropathy in which there is deposition of monosodium urate monohydrate in the synovium
What is the pathophysiological cause of gout?
It is related to chronic hyperuricaemia, with uric acid levels > 0.45 mmol/l.
What joint is most commonly affected by gout?
First metatarsophalangeal (MTP) joint, which is the base of the big toe
What are the three other joints commonly affected by gout?
Wrist joint
Knee Joint
Ankle joint
What eleven risk factors are associated with gout?
Middle Aged, 30 – 50 Years Old
Male Gender
Family History
Chronic Kidney Disease
Lesch Nyan Syndrome
Psoriasis
High Purine Diet
Obesity
Alcoholism
Thiazide Diuretic Administration
Chemotherapy
What is Lesch Nyhan syndrome?
It is defined as a congential condition, in which there is hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) deficiency
This leads to purine breakdown, leading to hyperuricaemia
What is the inheritance of Lesch Nyhan syndrome?
X-linked recessive
What are the four clincal features of Lesch Nyhan syndrome?
Gout
Renal Failure
Neurological Deficits
Learning Difficulties
What are the six clinical features of gout?
Severe Joint Pain
Joint Swelling
Joint Erythema
Joint Warmth
Joint Tophi
Reduced Joint Function
What are tophi?
They are subcutaneous deposits of uric acid, which present on small joints and connective tissues of the hands, elbows and ears
What three investigations are used to diagnose gout?
Blood Tests
Joint X-Ray
Joint Fluid Aspiration
When are blood tests used to diagnose gout? Why?
They should be conducted once the acute episode has settled, usually two weeks following
This is due to the fact that during an acute attack the uric acid level may be increased, normal or decreased
What blood test result indicates gout?
Increased Uric Acid Levels
What are the five features of gout on joint x-ray?
Normal Joint Space
Joint Effusion
Lytic Bone Lesions
Punched Out Erosions
Soft Tissue Tophi
Describe the puched out erosions of gout on joint x-rays
They have sclerotic boarders with overhanding edges
What are the four features of gout on joint fluid aspiration?
No Bacterial Growth
Needle Shaped Crystals
Negative Birefringent of Polarised Light
Monosodium Urate Crystals
What are the three pharmacologcial management options of acute gout attacks?
NSAIDs
Colchicine
Corticosteroids
When are NSAIDs used to manage acute gout attacks?
They are the first line management option
Name two NSAIDs used to manage acute gout attacks
Ibuprofen
Naproxen
When is colchicine used to manage acute gout attacks?
It is the second line management option of acute gout attacks, in which NSAIDs are contraindicated – such as renal impairment, heart disease, and peptic ulcers, etc
What is the mechanism of action of colchicine?
It is an anti-inflammatory drug, which inhibits microtubule polymerisation by binding to tubulin, interfering with mitosis
What is a contraindication of colchicine?
Renal Impairment, eGFR < 10ml/min
The dose should be reduced when the eGFR is between 10 - 15ml/min
What is a side effect of colchicine?
Diarrhoea
When are corticosteroids used to manage acute gout attacks?
They are the third line management option
Name a corticosteroid used to manage acute gout attacks
Prednisolone
When is prophylactic management of gout recommended?
It should be offered to all individuals who present with their first attack of gout
In which five circumstances is prophylactic management of gout particualrly recommended?
> 2 Gout Attacks In 12 Months
Gout Tophi
Chronic Kidney Disease
Uric Acid Renal Stones
Thiazide Diuretic Administration
What are the three prophylactic conservative management options of gout?
Reduce Alcohol Intake
Weight Loss
Low Purine Diet
When should prophylactic pharmacological management option of gout be commenced? Why?
When the inflammation has settled, and the patient is no longer in pain – usually 2- 4 weeks after the initial attack
This is due to the fact that starting pharmacological prophylaxis too early may precipitate a further attack
Do we continue prophylactic pharmacological management of gout during acute attacks when already administered?
Yes
What are the three prophylactic pharmacological management options of gout?
Allopurinol
Febuxostat
Urate Oxidase
When is allopurinol used to prophylactically manage gout?
It is the first line pharmacological management option
What is the mechanism of action of allopurinol?
It is a xanthine oxidate inhibitor, which means that it blocks uric acid production
How do we administer allopurinol to manage gout prophylactically?
It is initially commenced 100mg once daily, with gradual titration until a serum uric acid of 360umol/l is obtained
In which three circumstances should the target uric acid level be lowered to <300umol/l?
Gout tophi
Chronic gouty arthritis
Recurrent gout flares
What should allopurinol initially be administered with?
Colchicine cover
When colchicine is not tolerated, NSAIDs can alternatively be used
What drug does allopurinol interact with? What adverse reaction occurs?
Azathioprine
Azathioprine Toxicity
What are the four clinical features of azathioprine toxicity?
Bone Marrow Suppression
Depression
Nausea & Vomiting
Pancreatitis
When is febuxostat used to prophylactically manage gout?
It is the second line pharmacological management option
What is the mechanism of action of febuxostat?
It is a xanthine oxidate inhibitor, which means that it blocks uric acid production
When is urate oxidase used to prophylactically manage gout?
It is the third line pharmacological management
What is the mechanism of action of urate oxidase?
It is an enzyme which catalyses the conversion of urate to the degradation product allantoin
