HPE Grunenthal handbook - Page 11

and with 600mg allopurinol daily, his serum urate dropped to 320 micromolar (5.37mg/dl) with urate excretion 1.2mM (20mg/dl) and FeUA 2.6% (a very low urate clearance enabling hyperuricaemia) with GFR >60. The serum urate level reached was < 360 micromolar (<6mg/dl) range recommended by ACR EULAR demand, so can be called adequate. With the available guidelines for gout treatment (BSR, ACP, EULAR), we need to treat up to a predefined target and thus escalate doses of XOIs to achieve success. In similar complex gout cases having specialised care, the serum urate target often is set at 300 micromolar (5mg/dl); particularly in young persons with an adequate renal function, an escalation regimen with allopurinol is the rational course of action. In some patients, the pre-defined target of 300 micromolar is not reached and adding a uricosuric should be considered at some stage. But if the clinical situation reached is adequate, there is no requirement to pursue the <300 micromolar target (<5mg/dl) as literature lacks clear evidence for doing so. Case study 3 cartilage, tophaceous debris (in subcutaneous tissue) and gout attacks. These attacks may vary from mild arthropathy to severe debilitating attacks and can be sporadic, recurrent or continous. Even in the milder cases, treating to a significantly lower serum urate target resolves locomotor problems fully. Common doses of XOIs can help with this eradication perfectly. Many general practitioners therefore prescribe up to 300mg allopurinol (to reach the treatment goal of serum uric acid <0.36mmol/l (<6mg/dl)) . Up-titration of the allopurinol dose in such cases is often not needed; what is needed, however, is a second measurement of serum urate in order to know whether the predefined serum urate target has been reached. Case study 2 An overweight 50-year-old man with hypertension and a family history of gout (father had gout) who suffered from an annual gout attack in the big toe over a three-year period, now presenting with a debilitating gonarthritis. He was unable to walk without assistance and could not work. He used a betablocker and thiazide, and regularly consumed alcohol, particularly at weekends. Physical examination Healthy appearance, BMI 31.5 with some residual redness over his knee joint, unilaterally Ultrasonography Double contour sign leftsided MTP1 and affected knee with grade 2 power Doppler X-rays forefeet Slight degeneration MTP1 with a subcortical cyst Gout calculator Score 9.5 (highly suggestive for gout) Laboratory test Serum urate 640 micromolar (10.76mg/dl) with GFR >60 serum creatinine 90 ESR 30 and CRP 15.0; urate excretion 4.0mM (67.2mg/dl); fractional urate excretion 2.6% (urine portion) Course Dietary advice with colchicine 0.5mg twice daily. Glucocorticoid injection in the knee provided instant relief and allowed the opportunity to look for crystals under polarised light microscopy. Allopurinol also initiated: with 300mg daily, his urate dropped to 400 micromolar (6.72mg/dl), A 59-year-old man (slightly overweight) and a family history of gout (father had gout) and suffering from an protracted gout attack in the big toe during several months. He had suffered gout for for more than ten years, having just one attack annually. However, he was now unable to do his job, and had difficulty walking and sleeping. He used simvastatin for his elevated serum cholesterol and a puffer for bronchial hyper-reactivity, had a normal diet with regular, moderate alcohol consumption, particularly in the weekends. Physical examination A healthy man with weight 83kg and BMI 26.8 with some redness over his painful MTP1 joint, unilaterally. Ultrasonography Double contour sign leftsided MTP1 with grade 2 power Doppler X-rays forefeet Slight degeneration MTP1 with a subcortical cyst and overhanging edge. Gout calculator: score 10.5 ( highly suggestive for gout) Laboratory test Serum urate 620 micromolar (10.42mg/dl) with GFR>60 serum creatinine 90 ESR 40 and CRP 20.0; fractional urate excretion 2.6% (urine portion). This is a very low urate clearance leading to hyperuricaemia. Course Initially dietary advice (reduce calories and purine ingestion/stop beer and increase coffee intake) and stick to 100 grams of meat daily with colchicine 0.5mg twice daily. Started allopurinol: with 300mg daily, his urate dropped to 370 micromolar (6.22mg/dl) with urate excretion 0.4mM (6.72mg/dl), and with 300mg allopurinol plus 100mg benzbromarone daily, his serum urate dropped to 190 micromolar (3.19mg/ dl), with fractional urate excretion 12.1% with GFR >60. After one year, ultrasonography showed no double contour sign. Advised continuation of 300mg allopurinol monotherapy, resulting in an asymptomatic disease The combined use of XOI plus uricosuric can be very useful for rapid debulking. Most patients do tolerate the combination and will reach serum urate levels <200 micromolar, enabling a rapid dissolution of monosodium urate crystals. This, of course, can be performed safely when renal function is still adequate as uricosuria is a challenge for the tubules and renal function in general. Not all patients require lifelong XOIs plus uricosurics, but it can hospitalpharmacyeurope.com | 2018 | 11