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1.
Ann Rheum Dis ; 82(12): 1626-1634, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37652661

RESUMO

OBJECTIVES: To determine whether placebo is non-inferior to low-dose colchicine for reducing gout flares during the first 6 months of allopurinol using the 'start-low go-slow' dose approach. METHODS: A 12-month double-blind, placebo-controlled non-inferiority trial was undertaken. Adults with at least one gout flare in the preceding 6 months, fulfilling the American College of Rheumatology (ACR) recommendations for starting urate-lowering therapy and serum urate ≥0.36 mmol/L were recruited. Participants were randomised 1:1 to colchicine 0.5 mg daily or placebo for the first 6 months. All participants commenced allopurinol, increasing monthly to achieve target urate <0.36 mmol/L. The primary efficacy outcome was the mean number of gout flares/month between 0 and 6 months, with a prespecified non-inferiority margin of 0.12 gout flares/month. The primary safety outcome was adverse events over the first 6 months. RESULTS: Two hundred participants were randomised. The mean (95% CI) number of gout flares/month between baseline and month 6 was 0.61 (0.47 to 0.74) in the placebo group compared with 0.35 (0.22 to 0.49) in the colchicine group, mean difference 0.25 (0.07 to 0.44), non-inferiority p=0.92. There was no difference in the mean number of gout flares/month between randomised groups over the 12-month period (p=0.68). There were 11 serious adverse events in 7 participants receiving colchicine and 3 in 2 receiving placebo. CONCLUSIONS: Placebo is not non-inferior to colchicine in prevention of gout flares in the first 6 months of starting allopurinol using the 'start-low go-slow' strategy. After stopping colchicine, gout flares rise with no difference in the mean number of gout flares/month between groups over a 12-month period. TRIAL REGISTRATION NUMBER: ACTRN 12618001179224.


Assuntos
Gota , Adulto , Humanos , Gota/tratamento farmacológico , Alopurinol/uso terapêutico , Colchicina/uso terapêutico , Supressores da Gota/uso terapêutico , Ácido Úrico , Exacerbação dos Sintomas , Resultado do Tratamento
2.
Intern Med J ; 49(7): 838-842, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30426652

RESUMO

BACKGROUND: The management of gout in chronic kidney disease and end-stage renal disease is challenging and remains controversial. There are limited data on the use of urate-lowering therapy in people receiving dialysis. AIM: To estimate the point prevalence of gout, gout treatment and achievement of target serum urate (SU) among adults treated with long-term dialysis. METHODS: Three secular cohorts of adults receiving dialysis for at least 90 days on 1 February 2017, 1 January 2016 and 1 January 2015 were identified. Medical records were reviewed for SU concentrations. Results were compared between haemodialysis (HD) and peritoneal dialysis (PD), and participants prescribed and not prescribed urate-lowering therapy. The percentage reduction in SU 24- and 48-h post-HD was estimated based on data from a previous study. SU concentrations were then used to estimate the percentage time the SU was <0.36 mmol/L using linear interpolation. RESULTS: Of 216 dialysis patients, 61 (point prevalence 28.2%, 95% confidence interval 22.35-34.8%) had a diagnosis of gout. The mean (SD) age among those with gout was 61 years (14.4), 46 (75.4%) were men and 18 (31.1%) identified as Maori or Pacific Island. Forty-two (68.9%) were prescribed allopurinol (mean (SD) dose 116.0 ± 66.9 mg/day). 46% had a predialysis SU ≤0.36 mmol/L on less than 25% of occasions and 23% were below target on 76-100% of occasions. SU was below target 41% of time, with no statistically significant difference in those on HD or PD (P = 0.39), and those prescribed or not prescribed allopurinol (P = 0.55). CONCLUSIONS: Gout is experienced by approximately one in four adults treated with dialysis and two-thirds are prescribed allopurinol. A minority have SU at a target sufficient to prevent gout despite allopurinol and HD. A treat to target SU should be considered in those with SU above target.


Assuntos
Gota/sangue , Gota/tratamento farmacológico , Diálise Renal/tendências , Ácido Úrico/sangue , Idoso , Alopurinol/uso terapêutico , Estudos de Coortes , Estudos Transversais , Feminino , Gota/diagnóstico , Supressores da Gota/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
3.
J Clin Rheumatol ; 25(7): 284-287, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30001258

RESUMO

BACKGROUND/OBJECTIVE: The aim of this study was to determine whether reducing the dose of supplemental folic acid used in conjunction with methotrexate (MTX) therapy in people with active rheumatoid arthritis (RA) improved disease control and/or increased MTX-related adverse effects. METHODS: A randomized double-blind randomized controlled trial comparing 5 mg/wk and 0.8 mg/wk folic acid was undertaken. Rheumatoid arthritis patients on MTX for 3 months or more at a stable dose for 1 month or more were recruited. All participants had DAS28 of 3.2 or greater or required a change in therapy determined by the treating clinician. Disease activity, full blood count, liver function tests, red blood cell (RBC) folate, and RBC MTX polyglutamates were assessed at weeks 0, 4, 8, 16, and 24 along with reports of adverse events. RESULTS: Forty participants were recruited. The mean (SD) change in RBC folate between week 0 and 24 was +87.9 (57.4) nmol/L in the high-dose group and -113.3 (65.7) nmol/L in the low-dose group (p < 0.05). There was no significant difference in the change in DAS28 between the high- and low-dose groups at 24 weeks (-0.13 [95% confidence interval, -0.69 to 0.43] vs -0.25 [-0.87 to 0.37], respectively [p = 0.78]). There was no significant difference in MTX-related adverse effects between the 2 groups. CONCLUSIONS: A reduction in RBC folate secondary to reduction in folic acid dose was not associated with a change in RA disease activity or MTX-related adverse effects. The prevention of MTX-related adverse effects remains the primary reason for coprescribing folic acid with MTX. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR12610000739011).


Assuntos
Artrite Reumatoide , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Ácido Fólico/administração & dosagem , Metotrexato , Adulto , Antirreumáticos/administração & dosagem , Antirreumáticos/efeitos adversos , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/tratamento farmacológico , Relação Dose-Resposta a Droga , Método Duplo-Cego , Monitoramento de Medicamentos/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Feminino , Humanos , Masculino , Metotrexato/administração & dosagem , Metotrexato/efeitos adversos , Pessoa de Meia-Idade , Gravidade do Paciente , Projetos Piloto , Resultado do Tratamento , Complexo Vitamínico B/administração & dosagem
4.
Rheumatology (Oxford) ; 57(12): 2183-2189, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30107437

RESUMO

Objectives: To determine factors that predict inadequate serum urate (SU) lowering response in a randomized controlled trial of allopurinol dose escalation (DE) in gout. Methods: Participants undergoing allopurinol DE were classified as: complete response (CR)-reached target SU at month 9 and 12 of the DE phase or if still dose escalating at month 9 reached target SU by month 12; partial response (PR)-reached target at some stage but not fulfilling criteria for CR; or inadequate response (IR)-did not reach target SU at any time. Results: IR was uncommon, occurring in 13/150 (8.7%), compared with 82 (54.7%) CR, and 55 (36.6%) PR. Mean (s.e.m.) SU was higher at the end of the 12-month DE in IR compared with both CR and PR groups; 7.6 (0.31) vs 5.01 (0.06) and 5.97 (0.17) mg/dl respectively (P < 0.001). In univariate analysis, compete responders tended to be older, be receiving less allopurinol, have longer gout duration and were more likely to be New Zealand (NZ) European ethnicity, compared with IR+PR. Using multi-variate logistic regression analysis, only longer duration of gout and NZ European ethnicity remained significant independent predictors of CR. Baseline SU ⩾ 8 mg/dl had a sensitivity of 69.2% and specificity of 85.1% in predicting IR. The odds ratio for an IR if baseline SU was ⩾8 mg/dl was 11.7 (95% CI 3.3, 41.2). Conclusion: A minority of people with gout never reach target SU when allopurinol dose is increased in a treat-to-target manner. Approximately one-third of those with SU ⩾ 8mg/dl despite allopurinol ⩾300mg/d have an IR to DE. Trial registration: Australian New Zealand Clinical Trails Registry, https://www.anzctr.org.au, ACTRN12611000845932.


Assuntos
Alopurinol/administração & dosagem , Supressores da Gota/administração & dosagem , Gota/sangue , Gota/tratamento farmacológico , Ácido Úrico/sangue , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
5.
Ann Rheum Dis ; 76(12): 2065-2070, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28830881

RESUMO

OBJECTIVES: To determine the long-term safety and efficacy of allopurinol dose escalation (DE) to achieve target serum urate (SU) in gout. METHODS: People, including those with chronic kidney disease, who completed the first 12 months of a randomised controlled trial continued into a 12-month extension study. Participants randomised to continue current dose for the first 12 months began allopurinol DE at month 12 if SU was ≥6 mg/dL (control/DE). Immediate DE participants who achieved target SU maintained allopurinol dose (DE/DE). The primary endpoints were reduction in SU and adverse events (AEs) at month 24. RESULTS: The mean (SE) change in SU from month 12 to 24 was -1.1 (0.2) mg/dL in control/DE and 0.1 (0.2) mg/dL in DE/DE group (p<0.001). There was a significant reduction in the percentage of individuals having a gout flare in the month prior to months 12 and 24 compared with baseline in both groups and in mean tophus size over 24 months, but no difference between randomised groups. There were similar numbers of AEs and serious adverse events between groups. CONCLUSIONS: The majority of people with gout tolerate higher than creatinine clearance-based allopurinol dose and achieve and maintain target SU. Slow allopurinol DE may be appropriate in clinical practice even in those with kidney impairment. TRIAL REGISTRATION NUMBER: ACTRN12611000845932.


Assuntos
Alopurinol/administração & dosagem , Supressores da Gota/administração & dosagem , Gota/sangue , Gota/tratamento farmacológico , Ácido Úrico/sangue , Idoso , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento
6.
Ann Rheum Dis ; 76(9): 1522-1528, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28314755

RESUMO

OBJECTIVES: To determine the efficacy and safety of allopurinol dose escalation using a treat-to-target serum urate (SU) approach. METHODS: A randomised, controlled, parallel-group, comparative clinical trial was undertaken. People with gout receiving at least creatinine clearance (CrCL)-based allopurinol dose for ≥1 month and SU ≥6 mg/dL were recruited. Participants were randomised to continue current dose (control) or allopurinol dose escalation for 12 months. In the dose escalation group, allopurinol was increased monthly until SU was <6 mg/dL. The primary endpoints were reduction in SU and adverse events (AEs). RESULTS: 183 participants (93 control, 90 dose escalation) were recruited. At baseline, mean (SD) urate was 7.15 (1.6) mg/dL and allopurinol dose 269 mg/day. 52% had CrCL<60 mL/min. Mean changes in SU at the final visit were -0.34 mg/dL in the control group and -1.5 mg/dL in the dose escalation group (p<0.001) with a mean difference of 1.2 mg/dL (95% CI 0.67 to 1.5, p<0.001). At month 12, 32% of controls and 69% in the dose escalation had SU <6 mg/dL. There were 43 serious AEs in 25 controls and 35 events in 22 dose escalation participants. Only one was considered probably related to allopurinol. Five control and five dose escalation participants died; none was considered allopurinol related. Mild elevations in LFTs were common in both groups, a few moderate increases in gamma glutamyl transferase (GGT) were noted. There was no difference in renal function changes between randomised groups. CONCLUSIONS: Higher than CrCL-based doses of allopurinol can effectively lower SU to treatment target in most people with gout. Allopurinol dose escalation is well tolerated. TRIAL REGISTRATION NUMBER: ANZCTR12611000845932; Results.


Assuntos
Alopurinol/administração & dosagem , Supressores da Gota/administração & dosagem , Gota/tratamento farmacológico , Planejamento de Assistência ao Paciente , Ácido Úrico/sangue , Idoso , Alanina Transaminase/sangue , Fosfatase Alcalina/sangue , Aspartato Aminotransferases/sangue , Doença Hepática Induzida por Substâncias e Drogas/sangue , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Relação Dose-Resposta a Droga , Feminino , Gota/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , gama-Glutamiltransferase/sangue
7.
Eur J Clin Pharmacol ; 73(1): 71-78, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27683090

RESUMO

PURPOSE: The aims of this study were to characterise the population pharmacokinetics of oxypurinol in patients receiving haemodialysis and to compare oxypurinol exposure in dialysis and non-dialysis patients. METHODS: Oxypurinol plasma concentrations from 6 gout people receiving haemodialysis and 19 people with gout not receiving dialysis were used to develop a population pharmacokinetic model in NONMEM. Deterministic simulations were used to predict the steady-state area under the oxypurinol plasma concentration time curve over 1 week (AUC7days). RESULTS: The pharmacokinetics of oxypurinol were best described by a one-compartment model with a separate parameter for dialytic clearance. Allopurinol 100 mg daily produced an AUC7days of 279 µmol/L h in dialysis patients, a value 50-75 % lower than the AUC7days predicted for patients with normal renal function taking 200 to 400 mg daily (427-855 µmol/L h). Dosing pre-dialysis resulted in about a 25-35 % reduction in exposure compared to post-dialysis. CONCLUSIONS: Oxypurinol is efficiently removed by dialysis. The population dialytic and total (non-dialytic) clearance of oxypurinol were found to be 8.23 and 1.23 L/h, standardised to a fat-free mass of 70 kg and creatinine clearance of 6 L/h, respectively. Our results suggest that if the combination of low-dose allopurinol and haemodialysis does not result in sustained urate lowering below treatment targets (serum urate ≤0.36 mmol/L), then allopurinol doses may be increased to optimise oxypurinol exposure.


Assuntos
Alopurinol/farmacocinética , Supressores da Gota/farmacocinética , Modelos Biológicos , Oxipurinol/sangue , Diálise Renal , Adulto , Idoso , Idoso de 80 Anos ou mais , Alopurinol/sangue , Feminino , Gota/sangue , Gota/tratamento farmacológico , Gota/metabolismo , Supressores da Gota/sangue , Humanos , Masculino , Pessoa de Meia-Idade
8.
Arthritis Rheum ; 65(6): 1636-42, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23681955

RESUMO

OBJECTIVE: Studies in human volunteers have shown that vitamin C reduces serum urate (SU) levels. The aim of this study was to determine the effects of vitamin C on SU levels in patients with gout. METHODS: Patients with gout and an SU level >0.36 mmoles/liter (6 mg/dl) were recruited. Twenty patients already taking allopurinol were randomized to receive an increase in the dose of allopurinol or to commence taking vitamin C (500 mg/day). Twenty patients who had not been taking allopurinol were randomized to start receiving either allopurinol (up to 100 mg/day) or vitamin C (500 mg/day). Levels of plasma ascorbate, creatinine, and SU were measured on day 0 and week 8. RESULTS: There was no significant difference in the baseline SU level or estimated glomerular filtration rate (eGFR) between those who received vitamin C and those who did not (for SU, mean ± SEM 0.50 ± 0.11 mmoles/liter [8.4 ± 1.8 mg/dl] versus 0.50 ± 0.09 mmoles/liter [8.4 ± 1.5 mg/dl]; for eGFR, mean ± SEM 65.5 ± 3.5 ml/minute/1.73 m(2) versus 67.9 ± 4.6 ml/minute/1.73 m(2) ). Among the randomized patients, 30% in the vitamin C group and 25% in the no vitamin C control group were receiving diuretics. In the patients receiving vitamin C, there was a significant increase between day 0 and week 8 in the plasma ascorbate level. The reduction in SU level over 8 weeks was significantly less in those patients receiving vitamin C compared to those who started or increased the dose of allopurinol (mean reduction 0.014 mmoles/liter [0.23 mg/dl] versus 0.118 mmoles/liter [1.9 mg/dl]; P < 0.001). CONCLUSION: A modest dosage of vitamin C (500 mg/day) for 8 weeks had no clinically significant urate-lowering effects in patients with gout, despite the fact that plasma ascorbate levels increased. These results differ from previous findings in healthy control subjects with hyperuricemia. The uricosuric effect of modest-dose vitamin C appears to be small in patients with gout, when administered as monotherapy or in combination with allopurinol.


Assuntos
Ácido Ascórbico/administração & dosagem , Suplementos Nutricionais , Gota/tratamento farmacológico , Ácido Úrico/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Alopurinol/administração & dosagem , Ácido Ascórbico/sangue , Creatinina/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Projetos Piloto , Resultado do Tratamento
9.
Rheumatology (Oxford) ; 52(1): 34-44, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22949727

RESUMO

Gout is a common form of arthritis. It is associated with a number of comorbidities, including hypertension, cardiovascular disease, renal impairment, diabetes, obesity, hyperlipidaemia and frequently in a combination known as the metabolic syndrome. These comorbidities and their treatment may have an effect on the development of gout and on the choice of therapeutic agent. Treatment of acute gout with short-term corticosteroids may be a safer option than either NSAIDs or colchicine in patients with significant renal and/or cardiac impairment. Sustained reduction of serum urate <0.36 mmol/l is required for long-term management of gout. The optimal dosing regimen for patients with renal impairment is the subject of on-going investigation. There is less experience with newer urate-lowering therapies. This review will consider the relationship between comorbidities and gout with a particular focus on the treatment of gout and the potential interactions between drugs used for gout and those for comorbid conditions.


Assuntos
Supressores da Gota/uso terapêutico , Gota/complicações , Corticosteroides/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Colchicina/uso terapêutico , Gota/tratamento farmacológico , Humanos , Fatores de Risco
10.
Rheumatology (Oxford) ; 51(9): 1670-6, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22539486

RESUMO

OBJECTIVE: To determine the effects of furosemide on serum urate (SU), plasma oxypurinol and urinary urate. METHODS: Twenty-three cases with gout receiving furosemide and allopurinol were recruited. Twenty-three controls with gout receiving allopurinol but no diuretics were matched on age, gender, estimated glomerular filtration rate and allopurinol dose. SU, plasma oxypurinol and urinary urate were assessed on a single occasion. The effects of a single dose of furosemide 40 mg were examined in a separate group of 10 patients receiving allopurinol but not diuretic. RESULTS: Cases had significantly higher SU and plasma oxypurinol compared with controls despite receiving similar doses of allopurinol. There was no difference in urinary urate excretion. There was a significant increase in area under the curve (AUC)(0-24) for oxypurinol after administration of furosemide 40 mg. CONCLUSION: The interaction between allopurinol and furosemide results in increased SU and plasma oxypurinol. The exact mechanisms remain unclear but complex interactions that result in attenuation of the hypouricaemic effects of oxypurinol are likely. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, www.anzctr.org.au, 12609000529246.


Assuntos
Alopurinol/farmacocinética , Diuréticos/farmacocinética , Furosemida/farmacocinética , Supressores da Gota/farmacocinética , Gota/tratamento farmacológico , Oxipurinol/sangue , Ácido Úrico/sangue , Adulto , Idoso , Alopurinol/uso terapêutico , Área Sob a Curva , Estudos de Casos e Controles , Diuréticos/uso terapêutico , Interações Medicamentosas , Quimioterapia Combinada , Feminino , Furosemida/uso terapêutico , Gota/metabolismo , Supressores da Gota/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Micção/efeitos dos fármacos
11.
Curr Rheumatol Rep ; 14(2): 165-72, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22258500

RESUMO

Acute and chronic gout are common complications following organ transplantation. Risk factors include those shared with the general population (eg, diuretic use) and transplant-specific risk factors (eg, cyclosporine). Clinical features of gout are similar to those seen in the general population, although tophi may be more common. A definitive diagnosis requires demonstration of monosodium urate crystals within synovial fluid or tophi. Treatment is often empiric, although a poor response should prompt joint aspiration to exclude septic arthritis. Corticosteroids are commonly used to treat acute gout due to the adverse profile and drug interactions with NSAIDs and colchicine. Sustained reduction of serum urate (≤6 mg/dL) is critical in long-term management. Allopurinol is the most commonly used agent, although vigilant monitoring is required if combined with azathioprine. Other options include febuxostat and benzbromarone. The role of newer agents such as interleukin-1 inhibitors and uricases remains to be determined. General measures should include minimizing diuretic use.


Assuntos
Gota/etiologia , Transplante de Órgãos/efeitos adversos , Corticosteroides/uso terapêutico , Colchicina/uso terapêutico , Gota/diagnóstico , Gota/tratamento farmacológico , Supressores da Gota/uso terapêutico , Humanos
12.
Arthritis Rheum ; 63(2): 412-21, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21279998

RESUMO

OBJECTIVE: To determine the efficacy and safety of increasing the allopurinol dose above the proposed creatinine clearance-based dose in patients with gout. METHODS: Patients with gout who had been receiving a stable dose of allopurinol for ≥ 1 month were recruited. The dose of allopurinol was increased to obtain the target serum urate level of <0.36 mmoles/liter (<6 mg/dl). Patients were seen monthly until the serum urate concentration was <0.36 mmoles/liter for 3 consecutive months and then were seen every 3 months for at least 12 months. Data were analyzed using the dosage of allopurinol (mg/day) greater than the recommended dosage, as defined by the Hande criteria. RESULTS: Ninety patients were enrolled. The mean age of the patients was 58.7 years (range 27-83 years), 87.9% were male, and 81.9% were of European ancestry. Forty-five patients had a serum urate concentration of ≥ 0.36 mmoles/liter, and the dose of allopurinol was increased in these patients. Rashes developed in 3 patients, and either allopurinol was discontinued or dose escalation was ceased in these patients. Seven patients were lost to followup or developed intervening medical problems that precluded dose escalation. In 31 (88.8%) of 35 patients who completed the study, the serum urate level was <0.36 mmoles/liter at 12 months. Two of the 5 patients who had a serum urate level ≥ 0.36 mmoles/liter had undetectable levels of plasma oxypurinol, indicating noncompliance with allopurinol treatment. A significant reduction in the serum urate concentration was observed for all allopurinol doses above the recommended dose. Eighteen of 45 patients were receiving furosemide; those receiving furosemide were just as likely as those not receiving furosemide to achieve a serum urate concentration of <0.36 mmoles/liter (72% versus 88.5%; P = 0.24). Patients receiving furosemide required a higher dose of allopurinol to achieve the target serum urate concentration. No serious adverse events were observed. CONCLUSION: Increasing the dose of allopurinol above the proposed creatinine clearance-based dose led to a significant reduction in the serum urate concentration. Approximately 89% of patients achieved a serum urate concentration of <0.36 mmoles/liter. In this cohort, toxicity was not increased in patients receiving higher doses of allopurinol, including those with renal impairment.


Assuntos
Alopurinol/uso terapêutico , Creatinina/metabolismo , Supressores da Gota/uso terapêutico , Gota/tratamento farmacológico , Hiperuricemia/tratamento farmacológico , Nefropatias/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Monitoramento de Medicamentos , Feminino , Gota/sangue , Gota/complicações , Humanos , Hiperuricemia/sangue , Hiperuricemia/complicações , Nefropatias/complicações , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Ácido Úrico/sangue
13.
Front Med (Lausanne) ; 9: 1057917, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36482913

RESUMO

Background/aim: To determine the epidemiology and clinical features of giant cell arteritis (GCA) in Canterbury, Aotearoa New Zealand, with a particular focus on extra-cranial large vessel disease. Methods: Patients with GCA were identified from radiology and pathology reports, outpatient letters and inpatient hospital admissions in the Canterbury New Zealand from 1 June 2011 to 31 May 2016. Data was collected retrospectively based on review of electronic medical records. Results: There were 142 cases of GCA identified. 65.5% of cases were female with a mean age of 74.2 years. The estimated population incidence for biopsy-proven GCA was 10.5 per 100,000 people over the age of 50 and incidence peaked between 80 and 84 years of age. 10/142 (7%) people were diagnosed with large vessel GCA, often presenting with non-specific symptoms and evidence of vascular insufficiency including limb claudication, vascular bruits, blood pressure and pulse discrepancy, or cerebrovascular accident. Those with limited cranial GCA were more likely to present with the cardinal clinical features of headache and jaw claudication. Patients across the two groups were treated similarly, but those with large vessel disease had greater long-term steroid burden. Rates of aortic complication were low across both groups, although available follow-up data was limited. Conclusion: This study is the first of its kind to describe the clinical characteristics of large vessel GCA in a New Zealand cohort. Despite small case numbers, two distinct subsets of disease were recognized, differentiating patients with cranial and large vessel disease. Our results suggest that utilization of an alternative diagnostic and therapeutic approach may be needed to manage patients with large vessel disease.

14.
Pharmacogenet Genomics ; 20(6): 367-76, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20386493

RESUMO

OBJECTIVES: To determine whether genetic polymorphisms within the folate pathway are associated with red blood cell (RBC) methotrexate (MTX) polyglutamate concentrations, RBC folate concentrations and MTX efficacy/toxicity. METHODS: Disease activity in 200 rheumatoid arthritis patients on MTX was assessed by swollen and tender joint counts and Disease Activity Score 28. Genetic polymorphisms shown to have an effect on gene expression or protein function were examined. RESULTS: RBC folate concentrations were significantly associated with MTHFR 677C>T (P=0.002), MTRR 66A>G (P<0.0001), MTHFD1 1958G>A (P=0.001) and SHMT 1420C>T (P=0.012), whereas no association of these polymorphisms with disease activity was observed. None of the polymorphisms tested predicted RBC MTX polyglutamate concentrations. There were weak associations between central nervous system adverse effects and AMPD1 34C>T (P=0.04) and between gastrointestinal adverse effects and MTHFD1 1958G>A (P=0.03) and ABCC2 IVS23+56T>C (P=0.045). There was a stronger association between any adverse effect and ABCG2 914C>A (P=0.004). CONCLUSION: Although RBC folate concentrations are associated with genetic polymorphisms within the folate pathway, these variants do not predict disease activity. To accurately evaluate whether any polymorphisms are reliable predictors of MTX efficacy or toxicity, large prospective clinical trials are required. Furthermore, application of a genome-wide association strategy is likely to uncover novel predictors of MTX response.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/genética , Ácido Fólico/metabolismo , Metotrexato/uso terapêutico , AMP Desaminase/genética , AMP Desaminase/metabolismo , AMP Desaminase/uso terapêutico , Artrite Reumatoide/sangue , Eritrócitos/metabolismo , Ferredoxina-NADP Redutase , Ácido Fólico/genética , Ácido Fólico/uso terapêutico , Estudo de Associação Genômica Ampla , Glicina Hidroximetiltransferase/genética , Glicina Hidroximetiltransferase/metabolismo , Humanos , Estudos Longitudinais , Metotrexato/efeitos adversos , Metotrexato/análogos & derivados , Metotrexato/metabolismo , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Proteína 2 Associada à Farmacorresistência Múltipla , Ácido Poliglutâmico/análogos & derivados , Polimorfismo Genético
15.
Best Pract Res Clin Rheumatol ; 34(4): 101501, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32265121

RESUMO

Allopurinol, a first line urate-lowering therapy, has been associated with serious cutaneous reactions that have a high mortality. A number of risk factors for these serious adverse reactions have been identified including ethnicity, HLA-B∗5801 genotype, kidney impairment, allopurinol starting dose, and concomitant diuretic use. There is a complex interplay between these risk factors, which may (albeit rarely) lead to allopurinol-related serious adverse events. Although oxypurinol, the active metabolite of allopurinol, has been implicated, there is no defined drug concentration at which the reaction will occur. There is no specific treatment other than the cessation of allopurinol and supportive care. Whether hemodialysis, which rapidly removes oxypurinol, improves outcomes remains to be determined. Strategies to help reduce this risk are therefore important, which includes screening for HLA-B∗5801 in high-risk individuals, commencing allopurinol at low dose, and educating patients about the signs and symptoms of severe cutaneous adverse reactions, and what to do if they occur.


Assuntos
Alopurinol/efeitos adversos , Hipersensibilidade a Drogas , Gota , Hipersensibilidade a Drogas/diagnóstico , Hipersensibilidade a Drogas/etiologia , Hipersensibilidade a Drogas/prevenção & controle , Gota/tratamento farmacológico , Supressores da Gota/efeitos adversos , Humanos , Oxipurinol/uso terapêutico
16.
Clin Transl Sci ; 13(1): 110-115, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31444839

RESUMO

The aims of this study were to determine factors that predict serum urate (SU) lowering response to allopurinol and the conversion of allopurinol to oxypurinol, and to determine a minimum therapeutic oxypurinol concentration. Data from 129 participants in a 24-month open, randomized, controlled, parallel-group, comparative clinical trial were analyzed. Allopurinol dose, SU, and plasma oxypurinol concentrations were available at multiple time points. The slope for the association between allopurinol dose and SU was calculated as a measure of sensitivity to allopurinol. The slope for the association between allopurinol dose and oxypurinol was calculated as a measure of allopurinol metabolism. Receiver operating characteristic (ROC) curves were used to identify a minimum oxypurinol concentration predictive of SU < 6 mg/dL. There was a wide range of SU concentrations for each allopurinol dose. The relationship between sensitivity to allopurinol and allopurinol metabolism for each 100 mg allopurinol dose increase varied between individuals. Body mass index (P = 0.023), creatinine clearance (CrCL; P = 0.037), ABCG2 Q141K (P = 0.019), and SU (P = 0.004) were associated with sensitivity to allopurinol. The minimum oxypurinol concentration for achieving the urate target was found to be about 104 µmol/L, but predictive accuracy was poor (ROC curve area under the curve (AUC) 0.65). The minimum therapeutic oxypurinol concentration was found to increase with decreasing renal function. Although there is a positive relationship between change in oxypurinol and change in SU concentration, a minimum therapeutic oxypurinol is dependent on CrCL and cannot reliably predict SU target. Other variables, including ABCG2 Q141K genotype, impact on sensitivity to allopurinol (ACTRN12611000845932).


Assuntos
Alopurinol/administração & dosagem , Supressores da Gota/administração & dosagem , Gota/tratamento farmacológico , Oxipurinol/sangue , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Idoso , Alopurinol/farmacocinética , Índice de Massa Corporal , Creatinina/sangue , Creatinina/metabolismo , Relação Dose-Resposta a Droga , Feminino , Gota/sangue , Gota/diagnóstico , Gota/genética , Supressores da Gota/farmacocinética , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Oxipurinol/metabolismo , Curva ROC , Eliminação Renal , Resultado do Tratamento , Ácido Úrico/sangue
17.
Arthritis Care Res (Hoboken) ; 71(3): 427-434, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29799677

RESUMO

OBJECTIVE: The language currently used to describe gout lacks standardization. The aim of this project was to develop a consensus statement on the labels and definitions used to describe the basic disease elements of gout. METHODS: Experts in gout (n = 130) were invited to participate in a Delphi exercise and face-to-face consensus meeting to reach consensus on the labeling and definitions for the basic disease elements of gout. Disease elements and labels in current use were derived from a content analysis of the contemporary medical literature, and the results of this analysis were used for item selection in the Delphi exercise and face-to-face consensus meeting. RESULTS: There were 51 respondents to the Delphi exercise and 30 attendees at the face-to-face meeting. Consensus agreement (≥80%) was achieved for the labels of 8 disease elements through the Delphi exercise; the remaining 3 labels reached consensus agreement through the face-to-face consensus meeting. The agreed labels were monosodium urate crystals, urate, hyperuric(a)emia, tophus, subcutaneous tophus, gout flare, intercritical gout, chronic gouty arthritis, imaging evidence of monosodium urate crystal deposition, gouty bone erosion, and podagra. Participants at the face-to-face meeting achieved consensus agreement for the definitions of all 11 elements and a recommendation that the label "chronic gout" should not be used. CONCLUSION: Consensus agreement was achieved for the labels and definitions of 11 elements representing the fundamental components of gout etiology, pathophysiology, and clinical presentation. The Gout, Hyperuricemia, and Crystal-Associated Disease Network recommends the use of these labels when describing the basic disease elements of gout.


Assuntos
Consenso , Artropatias por Cristais/diagnóstico , Técnica Delphi , Gota/diagnóstico , Hiperuricemia/diagnóstico , Artropatias por Cristais/classificação , Gota/classificação , Humanos , Hiperuricemia/classificação , Ácido Úrico/análise
18.
Arthritis Res Ther ; 20(1): 255, 2018 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-30446002

RESUMO

OBJECTIVE: Allopurinol dosing has frequently been limited based on creatinine clearance (CrCL), resulting in failure to achieve target serum urate (SU). The aim of this analysis was to determine how many milligrams of allopurinol above the recommended CrCL-based dose (R+) are required to achieve target SU and to investigate the factors that influence R+. METHODS: We analysed data from participants in a 24-month open, randomized, controlled, parallel-group, comparative clinical trial. Data obtained during the 12-month dose escalation (DE) phase of the study (year 1 for DE/DE and year 2 for control/DE) were combined. R+ dose was defined as the number of milligrams of allopurinol above the CrCL-based dose at the final visit. RESULTS: Of the 132 participants, R+ allopurinol dose at the final visit was ≤ 100 mg/day in 38 (28.8%), 101-200 mg/day in 46 (34.8%) and > 200 mg/day in 48 participants (37.1%). There was no significant difference between the R+ groups in the number of participants achieving target SU. There was an increase in plasma oxypurinol and a larger percentage and absolute change in SU as R+ increased. Multivariate analysis revealed CrCL, weight, baseline SU and allopurinol dose, were significantly positively associated with allopurinol dose at 12 months. There were no significant differences across R+ groups in renal or liver function adverse events, although there were numerically more serious adverse events in the higher R+ groups. CONCLUSION: A wide range of R+ doses are required to achieve target SU. Four easily obtained clinical variables (baseline SU, CrCL, weight, and allopurinol dose) may be helpful to predict allopurinol dose. TRIAL REGISTRATION: ANZCTR, ACTRN12611000845932 . Registered on 10 August 2011.


Assuntos
Alopurinol/administração & dosagem , Creatinina/sangue , Supressores da Gota/administração & dosagem , Gota/sangue , Taxa de Depuração Metabólica/efeitos dos fármacos , Ácido Úrico/sangue , Adulto , Idoso , Relação Dose-Resposta a Droga , Sistemas de Liberação de Medicamentos/métodos , Feminino , Gota/tratamento farmacológico , Humanos , Masculino , Taxa de Depuração Metabólica/fisiologia , Pessoa de Meia-Idade , Ácido Úrico/antagonistas & inibidores
19.
Pathology ; 39(2): 258-63, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17454758

RESUMO

AIM: To compare the performance of a capture proteinase 3 enzyme linked immunosorbent assay (PR3 ELISA) with a direct PR3 ELISA in the measurement of PR3 antineutrophil cytoplasmic antibodies (ANCA). METHOD: The performance of both assays systems was compared using two sets of sera. Sera from patients (n = 49) suffering from Wegener's granulomatosis (WG) and fulfilling the American College of Rheumatology classification criteria (or a modification of those criteria that allowed for ANCA positivity) were used along with sera from a group of patients (n = 48) considered to have a clinically false positive PR3 ANCA result when measured by routine direct ELISA. RESULTS: Using the assay specific cut-offs, the direct ELISA gave a positive result in 92% on repeat testing and the capture ELISA a positive result in 84% of sera from patients with WG. The capture ELISA was negative in 75% of patients considered to have a false positive PR3 ANCA on initial testing by direct ELISA (27% were negative on repeat testing by direct ELISA). The mean concentration of PR3 ANCA in WG patient sera measured by the capture ELISA was significantly higher than that measured by the direct ELISA. The capture PR3 ELISA had a broader analytical range which was also reflected in PR3 ANCA concentrations measured in serial serum samples from WG patients. CONCLUSION: In this study the direct PR3 ELISA performed better as a screening test for PR3 ANCA compared with the capture PR3 ELISA, mainly because the cut-off for the capture ELISA needed to be set higher to avoid non-specific binding. In contrast, the improved analytical range of the capture ELISA made it a potentially more useful method for monitoring serial PR3 ANCA concentrations. In specific serum samples the capture ELISA was better able to discriminate 'false positive' PR3 ANCA.


Assuntos
Anticorpos Anticitoplasma de Neutrófilos/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Mieloblastina/imunologia , Anticorpos Monoclonais , Reações Falso-Positivas , Granulomatose com Poliangiite/diagnóstico , Humanos , Sensibilidade e Especificidade
20.
J Rheumatol ; 44(10): 1493-1498, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28765252

RESUMO

OBJECTIVE: Management of gout is frequently suboptimal. The aim of this study was to determine the proportion of patients presenting to Christchurch Hospital for a gout flare and to determine whether management for both acute flares and urate lowering was in accordance with international recommendations. METHODS: A retrospective audit was undertaken of all admissions to Christchurch Hospital from June 1, 2013, to May 31, 2014, in which gout was coded as a primary or secondary discharge diagnosis. Information including demographics, comorbidities, concomitant medications, treatment of acute gout, and urate lowering was collected. RESULTS: A total of 235 acute admissions for gout in 216 individuals were identified. Eleven individuals had 2 admissions and 4 individuals had 3 admissions. In 95/235 admissions (40.4%), gout was the primary diagnosis. Gout accounted for 95/77,321 (0.12%) of acute admissions. The treatment of acute gout was prednisone monotherapy in 170/235 (72.3%) of admissions. Serum urate was measured at some point during 123/235 (52.3%) of admissions, with only 19/123 (15.4%) at target urate level (< 0.36 mmol/l). At 60 of the 235 admissions, urate-lowering therapy was already being prescribed. Nine out of 175 patients (5.1%) not treated with urate-lowering therapy at admission commenced allopurinol and 32/174 (18.4%) had commencement of urate-lowering therapy recommended in the discharge plan. CONCLUSION: Rates of admission for gout are similar to that observed in other studies. Failure to initiate, change, or recommend alterations in urate-lowering therapy to achieve target urate in people with gout admitted to hospital represents a significant lost opportunity to improve longterm gout management.


Assuntos
Supressores da Gota/uso terapêutico , Gota/tratamento farmacológico , Ácido Úrico/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Gerenciamento Clínico , Feminino , Gota/sangue , Fidelidade a Diretrizes , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Estudos Retrospectivos , Resultado do Tratamento
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