allopurinol and Anorexia-Nervosa

BACKGROUND Gout is characterized by deposition of uric acid crystals (monosodium urate) in tissues and fluids. This can cause acute inflammatory arthritis. The 2015 ACR/EULAR criteria for the diagnosis of gout include dual energy computed tomography (DECT)-demonstrated monosodium urate crystals as a new criterion. DECT is a spectral decomposition that permits recognition of different types of tissues based on their characteristic energy-dependent photon attenuation. A positive scan is defined as the presence of urate at articular or periarticular sites. CASE REPORT We describe a 51-year-old woman known to have anorexia nervosa. During our clinical examination, we detected plenty of tophi on both hands, but no swollen joints. The diagnosis of gout was made by visualizing crystals in a biopsy from a tophus. The first line of treatment was allopurinol, the second line was rasburicase, and the current treatment is febuxostat 80 mg/day, allopurinol 300 mg twice a day, and colchicine 0.5 mg twice a day. The patient has unchanged arthralgia and the size and number of tophi remain the same as before treatment in spite of active treatment for 3 years. Previously the patient had problems with adherence, but now she claims that she follows the proposed treatment. The last plasma urate (P-urate) was 0.57 mmol/L. Following two years of treatment, DECT of hands visualized monosodium urate crystal deposits in the tophi, as seen on the clinical photos, but also crystals in relation to the tendons and soft tissue.  CONCLUSIONS DECT is an imaging modality useful to assess urate crystal deposits at diagnosis of gout and could be considered during treatment evaluation. Lack of adherence to treatment should be considered when P-urate values vary significantly and when DECT scans over years persistently visualize monosodium urate crystals.

Topics: Absorptiometry, Photon; Allopurinol; Anorexia Nervosa; Biomarkers; Biopsy; Colchicine; Drug Therapy, Combination; Febuxostat; Female; Gout; Gout Suppressants; Humans; Middle Aged; Patient Compliance; Predictive Value of Tests; Sensitivity and Specificity; Urate Oxidase; Uric Acid

A 49 year old female patient with anorexia nervosa was admitted to the hospital because of treatment-refractory hyperuricemia and gout. Medical history and clinical findings were compatible with primary gout and uric acid nephropathy. The patient stated that she regularly took allopurinol. In the hospital she initially received 300 mg allopurinol daily after breakfast. In order to ensure allopurinol ingestion and absorption the plasma concentrations of both allopurinol and its active metabolite oxipurinol were determined in addition to serum uric acid and further clinical chemistry data. Despite allopurinol treatment no decrease of serum uric acid was observed for three days. Therefore the head nurse was instructed to supervise the intake of allopurinol carefully. During the following days serum uric acid decreased and plasma oxipurinol concentrations rose. On day 9 of treatment serum uric acid fell into the upper normal range. Therefore the patient was allowed to leave the hospital within a few days. However serum uric acid thereafter increased again while plasma oxipurinol declined. Later on it became evident that the patient had vomited self-induced approximately 15 minutes after allopurinol intake. In the meantime her husband had urged her to return home. Starting with day 18 benzbromarone treatment was added. Combined therapy with 400 mg allopurinol and 50 mg benzbromarone daily finally resulted in a serum uric acid concentration of 4.5 mg/dl at discharge from the hospital. About three weeks later the private physician again diagnosed hyperuricemia with serum uric acid values between 10 and 12 mg/dl. Meanwhile the patient needs to be dialysed due to end stage renal disease. Our observations show that self-induced vomiting to prevent effective treatment may be a disease-specific pattern of noncompliance with drug therapy in anorexia nervosa.

Topics: Allopurinol; Anorexia Nervosa; Female; Gout; Humans; Middle Aged; Patient Compliance; Treatment Failure; Uric Acid; Vomiting