Lecture 49: Pharmaceutical care of gout

How is gout classified within the spectrum of musculoskeletal disorders?

Gout is defined as a crystal arthropathy associated with hyperuricaemia.

What is important to find out in clinical history taking to discover if someone has gout?

Current symptoms - how many joints affected?

and where?

Symptom severity and onset of symptoms

Frequency and duration of attack

Diet

Function and impact on work

Family history of gout, hyperuricaemia, kidney

stones, renal disease

Comorbidities/other risk factors

What are the differential diagnosis of gout?

Bursitis, tenosynovitis, cellulitis, osteoarthritis, reactive arthritic, septic arthritis

Which specific joint is the most common site for a first presentation of gout and what is the specific term?

The first metatarsophalangeal (MTP) joint, commonly known as the big toe

Podagra

Which joints in the hand are most frequently affected by gouty inflammation?

The distal interphalangeal joints (DIPs)

The firm, white nodules under translucent skin caused by urate deposition are known as _.

Subcutaneous gouty tophi.

Name two common anatomical locations for tophi on the upper body, excluding the hands.

The helix of the ear and the olecranon process of the elbow.

According to NICE guidelines, what serum urate level (in $\mu mol/L$) confirms a diagnosis of gout?

360micromol/L

If a patient has a suspected gout flare but their serum urate is below 360 micromol/L when should the test be repeated?

2-4 weeks after the flare has settled.

Which three pro-inflammatory cytokines are primarily released when urate crystals are exposed in a joint?

TNFa, IL-1, IL-6

How do diuretics like loop and thiazide diuretics contribute to the pathogenesis of gout?

They increase the risk by reducing the renal excretion of urate.

What are the 3 main phases of gout and what are the characterisations of these?

1. Asymptomatic hyperuricaemia: a prolonged phase where uric acid levels are elevated without symptoms

2. Acute gouty arthritis: characterized by sudden and severe attacks of joint pain, often with intervals of no symptoms in between (months to years)

3. Chronic tophaceous gout: a late stage where tophi (urate crystal deposits) form, leading to joint damage and significant quality of life impairment

What is pseudogout?

Involves the deposition of calcium pyrophosphate crystals, typically affecting larger joints like the knee

Diagnosis confirmed through joint aspiration and analysis of the crystal type present in the synovial fluid

What condition must be ruled out if a patient is systemically unwell with a hot, swollen joint?

Septic arthritis.

What is the management for acute gout attacks?

Rest and elevate limb, keep joint exposed in cool environment, ice pack

Prevent using non-pharmacological measures, hydration, modification of diet/lifestyle

Colchicine, NSAIDs

Steroid injection

IV uricase

Which dietary item should patients avoid consuming while taking colchicine due to potential interactions?

Grapefruit or grapefruit juice.

Why is immediate hospital transfer required if a colchicine overdose is suspected, even if the patient appears well?

The signs and symptoms of toxicity are often delayed, and it is highly toxic with a narrow therapeutic window.

When starting Urate-Lowering Therapy (ULT) after a flare, what is the recommended waiting period?

Wait at least 2-4 weeks after the gout flare has settled.

For patients with chronic tophaceous gout, what is the target serum urate level (in micromol/L)?

<300 micromol/L

Why is Allopurinol preferred over Febuxostat as a first-line treatment for patients with major cardiovascular disease?

Some studies suggest Febuxostat increases the risk of cardiovascular death and all-cause mortality.

What severe dermatological reaction is a known safety issue associated with Febuxostat?

Stevens-Johnson syndrome.

What is the clinical indication for the biologic agent Canakinumab in gout management?

Symptomatic treatment of frequent attacks (at least 3 in 12 months) in patients who failed or are intolerant to NSAIDs/colchicine

Which enzyme converts urate into allantoin, a substance more soluble in urine?

Urate oxidase (Uricase).

Name three high-purine food types that patients with gout should reduce or avoid.

Red meat, offal (liver/kidney), and shellfish.

What is the 'treat-to-target' strategy in the long-term management of gout?

Starting low-dose ULT and increasing the dose monthly until the target serum urate level is reached.

What is gout a risk factor for?

Chronic kidney disease, myocardial infarction, and cardiovascular disease.

Why should 'crash diets' or high-protein diets be avoided by patients with gout?

They can cause rapid changes in urate levels, potentially triggering acute flares.

Advise patients to lose maximum

The 'butterfly rash' is a clinical sign that helps differentiate which condition from gout?

Systemic Lupus Erythematosus (Lupus).