Erosive Hand OsteoArthritis (EHOA): analysis of consecutive patients presenting with EHOA in a hospital-based rheumatology practice and its implications for an upcoming interventional study.

INTRODUCTION: Erosive Hand OsteoArthritis (EHOA) is a common rheumatological problem. We aim to determine characteristics of EHOA patients: comorbidities, radiographic erosivity and pain experienced after being diagnosed, in order to find which of these are potentially relevant in upcoming interventional trials. METHOD: Retrospective analysis of EHOA patients within the electronic database in one centre, with a telephone interview on pain as experienced even exceeding 12 months after being diagnosed. RESULTS: Eighty-four non-academic EHOA patients were found: 89% females (median age 69 years), 11% males (similar age distribution). Kellgren-Lawrence (KL) erosivity scores in both sexes were comparable; DIPs scored higher than PIP's. Comorbid conditions were crystal-induced arthritis, rheumatoid arthritis (RA) and psoriatic arthritis (PsA) in 8%, 5% and 1%, respectively; seropositivity for rheumatoid factor and anti-citrullinated protein antibodies in 8% and 1% respectively. Pain worst experienced often exceeded a visual analogue score of 5.0, but was unrelated to the total KL score. Some pain reduction was reached with non-steroidals (perorally/transcutaneously) as deduced from continued use in 1 in 3. CONCLUSIONS: In many EHOA patients, there is an unmet need regarding the treatment of pain, which per se was not directly correlated with erosivity score. Future studies may be designed considering the aforementioned characteristics, acting on the inflammatory process resulting in PIP/DIP erosions, with the exclusion of RA and PsA in order to get a clean study on EHOA. Several studies with monoclonal antibodies have been performed but demonstrated ineffectivity on the outcome of pain. Hope glooms with the arrival of innovative small molecules that may reach EHOA target cells. Key Points • Erosive handOA is a common problem in non-academic rheumatology; it is often associated with significant pain in both sexes exceeding a VASpain of 5.0 even years after being diagnosed; 1 in 3 found some relief in non-steroidals perorally/transcutaneously. • Future studies will have to focus on (episodic) inflammatory hand OA resulting in proven erosivity (EHOA) located in PIP plus DIP joints and may have to exclude comorbid active crystal-induced arthritis as well as rheumatoid/psoriatic arthritis and possibly even RF/ACPA seropositivity in order to get a clean study on EHOA. • As several big monoclonals have failed in EHOA, we may have to search for promising new drugs within the group of small molecules. These will have to show a significant pain-reducing effect and preferably also a disease-modifying osteoarthritis drug (DMOAD) effect.

Dapansutrile, an oral selective NLRP3 inflammasome inhibitor, for treatment of gout flares: an open-label, dose-adaptive, proof-of-concept, phase 2a trial.

BACKGROUND: Gout flares are driven by interleukin (IL)-1ß. Dapansutrile inhibits the NLRP3 inflammasome and subsequent activation of IL-1ß. In this study we aimed to investigate the safety and efficacy of orally administered dapansutrile in patients with a gout flare. METHODS: In this open-label, proof-of-concept, phase 2a trial, adult patients (aged 18-80 years) with a monoarticular monosodium urate crystal-proven gout flare were enrolled at an outpatient clinic in the Netherlands and sequentially assigned using a dose-adaptive design to receive 100 mg/day, 300 mg/day, 1000 mg/day, or 2000 mg/day oral dapansutrile for 8 days. The coprimary outcomes were change in patient-reported target joint pain from baseline to day 3 and from baseline to day 7, assessed in the per-protocol population (all patients who received at least 80% of the study drug and had no major protocol deviations). Safety was assessed in the intention-to-treat population. This trial is registered with the EU Clinical Trials Register, EudraCT 2016-000943-14, and is completed. FINDINGS: Between May 18, 2017, and Jan 21, 2019, 144 patients were assessed for eligibility, of whom 34 were enrolled and 29 were included in the per-protocol population (three patients were excluded due to receiving <80% of study drug and two had major protocol deviations): eight patients received 100 mg/day, seven received 300 mg/day, six received 1000 mg/day, and eight received 2000 mg/day. Between baseline and day 3, there was a mean reduction in patient-reported target joint pain of 52·4% (SD 32·94; p=0∙016) for the 100 mg/day group, 68·4% (34·29; p=0∙016) for the 300 mg/day group, 55·8% (44·90; p=0∙063) for the 1000 mg/day group, and 57·6% (38·72; p=0∙016) for the 2000 mg/day group. At day 7, there was a mean reduction of 82·1% (22·68; p=0∙031) for the 100 mg/day group, 84·2% (16·33; p=0∙016) for the 300 mg/day group, 68·9% (34·89; p=0∙031) for the 1000 mg/day group, and 83·9% (15·44; p=0∙008) for the 2000 mg/day group, compared to baseline. 25 (73·5%) of 34 patients reported a total of 45 treatment-emergent adverse events, most of which were metabolism and nutrition disorders (17 [37·8%]) and gastrointestinal disorders (ten [22·2%]). Two serious adverse events occurred during the study, admission to hospital because of worsening of gout flare at day 3, and admission to hospital because of coronary stenosis 18 days after the patient received their last dose; these were considered moderate in severity and unrelated to the study drug. INTERPRETATION: Dapansutrile is a specific NLRP3 inflammasome inhibitor with a satisfactory safety profile and efficacy in the reduction of target joint pain in this study. Future studies are needed to confirm the clinical potential of dapansutrile.

Rare genetic variants in interleukin-37 link this anti-inflammatory cytokine to the pathogenesis and treatment of gout.

OBJECTIVE: Gout is characterised by severe interleukin (IL)-1-mediated joint inflammation induced by monosodium urate crystals. Since IL-37 is a pivotal anti-inflammatory cytokine suppressing the activity of IL-1, we conducted genetic and functional studies aimed at elucidating the role of IL-37 in the pathogenesis and treatment of gout. METHODS: Variant identification was performed by DNA sequencing of all coding bases of IL37 using molecular inversion probe-based resequencing (discovery cohort: gout n=675, controls n=520) and TaqMan genotyping (validation cohort: gout n=2202, controls n=2295). Predictive modelling of the effects of rare variants on protein structure was followed by in vitro experiments evaluating the impact on protein function. Treatment with recombinant IL-37 was evaluated in vitro and in vivo in a mouse model of gout. RESULTS: We identified four rare variants in IL37 in six of the discovery gout patients; p.(A144P), p.(G174Dfs*16), p.(C181*) and p.(N182S), whereas none emerged in healthy controls (Fisher's exact p-value=0.043). All variants clustered in the functional domain of IL-37 in exon 5 (p-value=5.71×10-5). Predictive modelling and functional studies confirmed loss of anti-inflammatory functions and we substantiated the therapeutic potential of recombinant IL-37 in the treatment of gouty inflammation. Furthermore, the carrier status of p.(N182S)(rs752113534) was associated with increased risk (OR=1.81, p-value=0.031) of developing gout in hyperuricaemic individuals of Polynesian ancestry. CONCLUSION: Here, we provide genetic as well as mechanistic evidence for the role of IL-37 in the pathogenesis of gout, and highlight the therapeutic potential of recombinant IL-37 for the treatment of gouty arthritis.

A systematic literature review of patient-reported outcome measures used in gout: an evaluation of their content and measurement properties.

BACKGROUND: Gout is a common, monosodium urate crystal-driven inflammatory arthritis. Besides its clinical manifestations, patients often also suffer from pain, physical impairment, emotional distress and work productivity loss, as a result of the disease. Patient-reported outcome measures (PROMs) are commonly used to assess these consequences of the disease. However, current instrument endorsements for measuring such outcomes in acute and chronic gout clinical settings are based on limited psychometric evidence. The objective of this systematic literature review was to identify currently available PROMs for gout, and to critically evaluate their content and psychometric properties, in order to evaluate the current status regarding PROMs for use in gout patients. METHODS: Systematic literature searches were performed in the PubMed and EMBASE databases. The methodological quality of included papers was appraised using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist, and evaluation of measurement properties (reliability, responsiveness, construct validity, floor and ceiling effects) was done in accordance with published quality criteria. Item content was appraised by linking health concepts to the International Classification of Functioning Disability and Health (ICF) framework. RESULTS: In total, 13 PROMs were identified, of which three were targeted specifically at gout patients. The majority of the PROMs were rated positively for content validity. For most instruments, limited evidence was available for construct validity and reliability. Instruments to assess pain scored well on responsiveness and floor and ceiling effects, but not much is known about their reliability in gout. CONCLUSIONS: The physical functioning subscale of the SF-36v2 (Short Form-36 item version 2) is the only PROM that had sufficient supporting evidence for all its psychometric properties. Many of the commonly used PROMs in gout are currently not yet well supported and more studies on their measurement properties are needed among both acute and chronic gout populations.

Crystal-proven gout patients have an increased mortality due to cardiovascular diseases, cancer, and infectious diseases especially when having tophi and/or high serum uric acid levels: a prospective cohort study.

OBJECTIVE: To investigate the cause-specific mortality and the possible involved clinical characteristics with increased mortality in a cohort of 700 patients with crystal-proven gout. The cause-specific mortality of gout was compared to the mortality of the general population. METHODS: Patients with arthritis referred for diagnosis were consecutively included in the Gout Arnhem-Liemers Cohort (GOAL). Joint fluid analysis was performed in all patients and only crystal-proven gout patients were included in this study. At inclusion clinical characteristics and laboratory values were collected. At follow-up patients who died were identified. Standardized mortality ratios (SMRs) were calculated for all-causes, cardiovascular diseases, cancer, and infectious diseases using indirect standardization methods for mortality outcomes and compared with the general population. The clinical characteristics of the patients who died were compared with those of the survivors and were analyzed by a logistic regression analysis to identify any associations with mortality. RESULTS: The study population at inclusion contained 573 (81.9%) men and 127 (18.1%) females with an average age of 62.0 (SD 13.4). During 3500 person-years from inclusion visit till 31 May 2016, in 700 gout patients, 66 deaths (27 cardiovascular deaths, 15 cancer-related deaths, 8 infectious deaths, 16 various other causes) occurred in this cohort. The all-cause standardized mortality ratio in gout patients was 2.21 (95% CI 1.68-2.74). In this cohort, gout patients had a higher SMR for death attributed to cardiovascular diseases (6.75; 95% CI 4.64-8.86), infectious diseases (4.66; 95% CI 1.51-7.82) and cancer (3.58; 95% CI 1.77-5.39). Corrected for confounders high serum uric acid levels (SUA; > 0,56 mmol/L), tophaceous gout, a history of peripheral vascular disease, myocardial infarction, and heart failure at the inclusion visit were associated with increased mortality during follow-up. CONCLUSION: Compared to the general population, gout patients have an increased association with all-cause disease mortality, especially attributed to cardiovascular diseases, cancer, and infectious diseases. This association is strongest in hyperuricemic (uric acid levels > 0,56 mmol/l) and tophaceous patients and in those with a history of peripheral vascular disease, myocardial infarction, and heart failure. Preventive measures like treatment of high SUA levels and treatment of cardiovascular risk factors need to be considered and evaluated.

Anakinra for the treatment of acute gout flares: a randomized, double-blind, placebo-controlled, active-comparator, non-inferiority trial.

OBJECTIVES: To evaluate the efficacy and safety of anakinra in treating acute gout flares in a randomized, double-blind, placebo-controlled, active comparator, non-inferiority (NI) trial. METHODS: Patients with a crystal-proven acute gout flare were randomized (1: 1) to treatment with anakinra or treatment as usual (free choice: either colchicine, naproxen or prednisone). The primary end point was the change in pain between baseline and the averaged pain score on days 2-4 measured on a five-point rating scale. NI of anakinra would be established if the upper bound of the 95% CI of the numeric difference in changed pain scores between treatment groups did not exceed the NI limit of 0.4 in favour of treatment as usual, in the per-protocol (PP) and intention-to-treat (ITT) populations, assessed in an analysis of covariance model. Secondary outcomes included safety assessments, improvement in pain, swelling, tenderness and treatment response after 5 days, assessed using linear mixed models and binary logistic regression models. RESULTS: Forty-three patients received anakinra and 45 treatment as usual. Anakinra was non-inferior (mean difference; 95% CI) to treatment as usual in both the PP (-0.13; -0.44, 0.18) and ITT (-0.18; -0.44, 0.08) populations. No unexpected or uncommon (serious) adverse events were observed in either treatment arm. Analyses of secondary outcomes showed that patients in both groups reported similar significant reductions in their gout symptoms. CONCLUSION: Efficacy of anakinra was shown to be non-inferior to treatment as usual for the treatment of acute gout flares, suggesting that anakinra is an effective treatment alternative for acute gout flares. TRIAL REGISTRATION: Het Nederlands Trial Register, www.trialregister.nl, NTR5234.

Gout lessons from 2018: CARES, a direct comparison of febuxostat vs allopurinol, and CANTOS, IL1 blocker for cardiovascular risk minimisation.

In the Cardiovascular Safety of Febuxostat and Allopurinol in Patients with Gout and Cardiovascular Morbidities (CARES) trial conducted by White et al. (March 29 issue from NEJM), all-cause mortality and cardiovascular mortality are found to be higher among patients randomly assigned to febuxostat compared to allopurinol, but significant flaws are a clear lack of treat to target strategy with more powered treatment in the febuxostat arm, dysbalance with cardiovascular risk factors selectively in again the febuxostat arm, and discontinuation of the trial regimen in over 50% of patients with discontinuation of follow-up in about 45%. With these flaws, conclusions such as febuxostat-associated higher mortality are potentially if not probably incorrect, and thus febuxostat to be used not as first-line therapy may well be an invalid consequence? The paper here describes potential lessons to be taken.

Quality of care in gout: a clinical audit on treating to the target with urate lowering therapy in real-world gout patients.

The current paper aimed to describe the quality of care for gout patients by showing the clinical outcomes achieved in two patient cohorts in which differing targeted urate lowering therapy (ULT) treatment approaches were employed, both aiming to reach the European League Against Rheumatism recommended serum urate (sUA) targets. A retrospective medical chart review study was conducted. Data from the medical records of gout patients from two clinical centers in The Netherlands, both applying targeted ULT treatments (albeit using different approaches), were reviewed. Patients in cohort A were given a combination of xanthine oxidase inhibitors with uricosurics if treatment with allopurinol monotherapy failed to reach sUA target levels, whereas patients in cohort B were treated with sequential monotherapy. Data on patient characteristics and clinical outcomes were collected. A total of 177 patient dossiers were included: 99 from cohort A and 78 from cohort B. The great majority (n = 146, 82.5%) of the patients in both cohorts had a current sUA level <360 µmol/L. In addition, more than half (n = 104, 58.8%) of the patients met the stringent sUA target level of <300 µmol/L. The largest reductions in mean sUA levels were observed for patients who were treated with combination therapy. This clinical audit of two cohorts of gout patients provides initial-yet promising-results regarding the proportion of real-world gout patients in whom recommended that sUA target levels can be achieved, and demonstrates the added value that a targeted treatment approach may have in reaching these goals.

2015 Gout classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative.

OBJECTIVE: Existing criteria for the classification of gout have suboptimal sensitivity and/or specificity, and were developed at a time when advanced imaging was not available. The current effort was undertaken to develop new classification criteria for gout. METHODS: An international group of investigators, supported by the American College of Rheumatology and the European League Against Rheumatism, conducted a systematic review of the literature on advanced imaging of gout, a diagnostic study in which the presence of monosodium urate monohydrate (MSU) crystals in synovial fluid or tophus was the gold standard, a ranking exercise of paper patient cases, and a multi-criterion decision analysis exercise. These data formed the basis for developing the classification criteria, which were tested in an independent data set. RESULTS: The entry criterion for the new classification criteria requires the occurrence of at least one episode of peripheral joint or bursal swelling, pain, or tenderness. The presence of MSU crystals in a symptomatic joint/bursa (ie, synovial fluid) or in a tophus is a sufficient criterion for classification of the subject as having gout, and does not require further scoring. The domains of the new classification criteria include clinical (pattern of joint/bursa involvement, characteristics and time course of symptomatic episodes), laboratory (serum urate, MSU-negative synovial fluid aspirate), and imaging (double-contour sign on ultrasound or urate on dual-energy CT, radiographic gout-related erosion). The sensitivity and specificity of the criteria are high (92% and 89%, respectively). CONCLUSIONS: The new classification criteria, developed using a data-driven and decision-analytic approach, have excellent performance characteristics and incorporate current state-of-the-art evidence regarding gout.

2015 Gout Classification Criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative.

OBJECTIVE: Existing criteria for the classification of gout have suboptimal sensitivity and/or specificity, and were developed at a time when advanced imaging was not available. The current effort was undertaken to develop new classification criteria for gout. METHODS: An international group of investigators, supported by the American College of Rheumatology and the European League Against Rheumatism, conducted a systematic review of the literature on advanced imaging of gout, a diagnostic study in which the presence of monosodium urate monohydrate (MSU) crystals in synovial fluid or tophus was the gold standard, a ranking exercise of paper patient cases, and a multicriterion decision analysis exercise. These data formed the basis for developing the classification criteria, which were tested in an independent data set. RESULTS: The entry criterion for the new classification criteria requires the occurrence of at least 1 episode of peripheral joint or bursal swelling, pain, or tenderness. The presence of MSU crystals in a symptomatic joint/bursa (i.e., synovial fluid) or in a tophus is a sufficient criterion for classification of the subject as having gout, and does not require further scoring. The domains of the new classification criteria include clinical (pattern of joint/bursa involvement, characteristics and time course of symptomatic episodes), laboratory (serum urate, MSU-negative synovial fluid aspirate), and imaging (double-contour sign on ultrasound or urate on dual-energy computed tomography, radiographic gout-related erosion). The sensitivity and specificity of the criteria are high (92% and 89%, respectively). CONCLUSION: The new classification criteria, developed using a data-driven and decision analytic approach, have excellent performance characteristics and incorporate current state-of-the-art evidence regarding gout.

Personalizing treatment targets in rheumatoid arthritis by using a simple prediction model.

OBJECTIVE: To develop a personalized treatment target approach in patients with rheumatoid arthritis (RA) based on baseline risk factors for joint damage progression in combination with disease activity over time. METHODS: Data were used from the Nijmegen early RA cohort. Presence or absence of anticyclic citrullinated peptide antibodies (anti-CCP), high erythrocyte sedimentation rate, and erosions were translated into 4 risk profiles: 0, 1, 2, and 3. Joint damage progression was assessed with the Ratingen score, and disease activity with the original Disease Activity Score (DAS) over 3 years. The probability for joint damage progression was calculated for each risk profile and each DAS category using logistic regression models. The probabilities were translated into personalized disease activity treatment targets. RESULTS: More risk factors at baseline as well as a higher DAS level resulted in a higher probability for joint damage progression in a dose-dependent way. Low DAS corresponded with a probability of 0.0, 0.08, 0.20, and 0.58 in patients with 0, 1, 2, and 3 risk factors, respectively. Moderate DAS corresponded with a probability of 0.06 in patients with 0 risk factors and 0.35 with 1 risk factor. High DAS resulted in a probability of 0.50 with no risk factors present at baseline. CONCLUSION: Presence of anti-CCP, acute-phase response, and erosions at baseline can be used to set individual treatment targets in RA. In patients without these risk factors, a moderate DAS as a target is sufficient, while for patients with all 3 risk factors, a low DAS is not strict enough to limit the risk for joint damage.

[The multidisciplinary practice guideline "The responsible use of biologicals"]. / Multidisciplinaire richtlijn "Verantwoord gebruik van biologicals".

A multidisciplinary working group has developed a practice guideline containing various recommendations on the responsible and efficient use of biologicals. These biologicals include both soluble immune-receptor proteins and monoclonal antibodies that are aimed at immune mediators, receptors or cells. They are produced by biotechnology. Biologicals are used to treat patients with immune-mediated inflammatory disorders (IMIDs) such as rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis, juvenile idiopathic arthritis (JIA), psoriasis, ulcerative colitis, Crohn's disease, uveitis and sarcoidosis. This article summarises the most important recommendations contained in the practice guideline. The practice guideline is intended for members of the medical profession in addition to patients, who are considering, or are already, using biologicals.

Rituximab in cryoglobulinaemic vasculitis, evidence for its effectivity: a case report and review of literature.

Cryoglobulinaemia associated with systemic vasculitis mediated by immune complexes is a rare combination. These immune complexes are composed of immunoglobulins and precipitate when exposed to cold temperature. Cryoglobulinaemic vasculitis, treated or untreated, may lead to substantial morbidity and even mortality. Novel targeted therapies may well provide new therapeutic options following or perhaps even prior to the classical cytotoxic therapies. Systemic B cell depletion with rituximab, a chimeric monoclonal antibody against CD20 antigen, is commonly applied in patients with non-Hodgkin's lymphoma or in refractory rheumatoid factor-positive rheumatoid arthritis. Since B cell clones are the source of cryoglobulins, therapeutic effectiveness of rituximab in cryoglobulinaemic vasculitis may be expected. We describe a 72-year-old woman with mixed cryoglobulinaemia type 2, who has successfully been treated with rituximab infusions after failing on prednisone and azathioprine. We reviewed the literature and found 142 cases of cryoglobulinaemic vasculitis, 138 mixed (type 2 or 3) and four, type 1. Rituximab was applied mostly after failure on other treatments. Significant reduction in levels of rheumatoid factor, cryoglobulins and IgM were reported after rituximab therapy. Of the total 142, cases 119 could be evaluated for the response on rituximab therapy, the other 23 cases only regarding side effects. Of the 119 evaluated patients, 71 (60%) had complete response; 28 (23%), partial response and 20 patients (17%), no response. Data were not blinded or placebo-controlled. Side effects were seen in 27 of the 142 patients. Occurrence of the side effects was associated with high baseline levels of cryoglobulins, with a high dose of rituximab infusion of 1,000 mg and with a high level of complement activation. Death was reported four times and was related with the disease.

New advances in the treatment of gout: review of pegloticase.

Treatment-failure gout (TFG) affects approximately 50,000 patients or about 1% of the overall population of patients with gout in the United States of America. The severity of TFG is manifested by frequent acute attacks of disabling arthritis, chronic deforming joint disease, destructive masses of urate crystals (tophi), progressive physical disability, and poor health-related quality of life. Pegloticase (Krystexxa(®); Savient Pharmaceuticals, Inc), a novel PEGylated urate oxidase (uricase) enzyme, has been resubmitted for US Food and Drug Administration approval. In a 6-month, placebo-controlled clinical trial, 8 mg of pegloticase for every 2 weeks induced a lytic decrease of serum urate (sUr) concentrations, leading to dissolution of tophi in 40% of patients at final visit. However, 58% were nonresponders to the defined target sUr of 0.36 mmol/L (80% were nonresponders during months 3 and 6), possibly due to anti-body formation. Also, 26%-31% experienced infusion reactions (IRs) and 77% suffered from gout flares. Although long-term data are awaited, an anti-inflammatory strategy, eg, based on glucocorticosteroids, is needed to prevent pegloticase antibody formation leading to IRs and diminished or shortened efficacy, and might also prevent gout flares. According to the current clinical data, pegloticase might have an important role as a (bridging) treatment in sUr-responsive patients for tophi clearance in severe chronic refractory gout.

Management of hyperuricemia in gout: focus on febuxostat.

Gout is the most common inflammatory arthritis in an elderly population, and can be diagnosed with absolute certainty by polarization microscopy. However, diagnosis may be challenging because atypical presentations are more common in the elderly. Management of hyperuricemia in the elderly with gout requires special consideration because of co-medication, contra-indications, and risk of adverse reactions. Urate-lowering agents include allopurinol and uricosuric agents. These also must be used sensibly in the elderly, especially when renal function impairment is present. However, if used at the lowest dose that maintains the serum urate level below 5.0 to 6.0 mg/dL (0.30 to 0.36 mmol/L), the excess urate in the body will eventually be eliminated, acute flares will no longer occur, and tophi will resolve. Febuxostat, a new xanthine oxidase inhibitor, is welcomed, as few alternatives for allopurinol are available. Its pharmacokinetics and pharmacodynamics are not significantly altered in patients with moderate renal function or hepatic impairment. Its antihyperuricemic efficacy at 80 to 120 mg/day is better than "standard dosage" allopurinol (300 mg/day). Long-term safety data and efficacy data on tophus diminishment and reduction of gout flares have recently become available. Febuxostat may provide an important option in patients unable to use allopurinol, or refractory to allopurinol.

An evidence-based assessment of the clinical significance of drug-drug interactions between disease-modifying antirheumatic drugs and non-antirheumatic drugs according to rheumatologists and pharmacists.

BACKGROUND: Clinically relevant drug-drug interactions (DDIs) must be recognized in a timely manner and managed appropriately to prevent adverse drug reactions or therapeutic failure. Because the evidence for most DDIs is based on case reports or poorly documented clinical information, there is a need for better assessment of their clinical relevance. OBJECTIVE: This study evaluates the interdisciplinary agreement between rheumatologists and clinical (hospital) pharmacists in assessing the clinical relevance of DDIs with disease-modifying antirheumatic drugs (DMARDs) and non-DMARD medications. METHODS: Potential DDIs were identified from the medical literature using MEDLINE and EMBASE for the years 1968-2009. The following search terms were used for the key word, title, and abstract sections of the publications: interaction(s), DMARD, disease-modifying antirheumatic drug(s), antirheumatic, rheumatology, rheumatoid arthritis, and the names of the individual DMARDs of interest (abatacept, adalimumab, anakinra, auranofin, aurothioglucose, aurothiomalate, d-penicillamine, etanercept, gold, [hydroxy]-chloroquine, interleukin-1 receptor antagonist, IL1-RA, infliximab, leflunomide, methotrexate, rituximab, and sulfasalazine/sulphasalazine). Reference lists of the retrieved publications were searched for further information on potential DDIs. All pharmacodynamic or pharmacokinetic DDIs between a DMARD and a non-DMARD identified were included in the study, with the exception of evidence regarding DMARD doses higher than used in the treatment of rheumatoid arthritis and interactions with phytotherapeutic or homeopathic preparations. Using a standard information set for each DDI (eg, from product labeling, textbooks, and the medical literature), a group of rheumatologists and a group of clinical pharmacists independently assessed whether the individual drug-DMARD combinations interacted and whether they required immediate intervention. Both groups consisted of 3 members (2 men and 1 woman), aged 40 to 60 years, who had >5 years of clinical experience and were currently involved in clinical practice in large, nonacademic teaching hospitals in the Netherlands. RESULTS: Forty potential DDIs with DMARDs were retrieved and assessed by the 2 groups. For 30 (75%) of these, rheumatologists and clinical pharmacists agreed about the requirement for immediate intervention. Specifically, 17 drug combinations (43%) were judged to interact and to require immediate intervention, and 13 combinations (33%) were judged either not to interact or to interact but not to require immediate intervention. For 10 combinations (25%), rheumatologists and clinical pharmacists were not in agreement. Overall, agreement between the groups was good (kappa = 0.80) for judging whether the drug combinations were interactions, and agreement was fair (kappa = 0.39) for judging whether immediate intervention was required. Prospective analysis of the data showed that rheumatologists tended to recommend immediate intervention more often when the adverse reaction to the DDI involved an increased risk of toxicity of the DMARD. In contrast, clinical pharmacists more often advocated immediate intervention when the adverse reaction involved decreased effectiveness of the DMARD. CONCLUSION: For a subset of DMARD-drug combinations, rheumatologists and clinical pharmacists differed in their assessments of clinical relevance.

A simple method for quantification of allopurinol and oxipurinol in human serum by high-performance liquid chromatography with UV-detection.

OBJECTIVES: Allopurinol is a uric acid lowering drug used in the treatment of gout and the prevention of tumor lysis syndrome. Allopurinol and its active metabolite oxipurinol inhibit xanthine oxidase, which forms uric acid from xanthine and hypoxanthine. Therapeutic drug monitoring is an important option for evaluation and optimization of allopurinol treatment in case of renal impairment, interaction with uricosuric drugs or to verify patient adherence. In this study we developed and validated a simple quantitative assay using reverse phased high-performance liquid chromatography (HPLC) with UV-detection as a method for quantification of allopurinol and oxipurinol in human serum in the presence of different frequently used drugs. METHODS: The HPLC-UV method uses a mobile phase consisting of sodium acetate (0.02 M; pH 4.5), at a flow rate of 1.0 mL/min. Allopurinol and oxipurinol are detected by UV-absorption at 254 nm with a retention time of 9.9 min for oxipurinol and 12.3 min for allopurinol. Aciclovir is used as internal standard. RESULTS: Validation showed for allopurinol lower and upper limits of quantification of 0.5 and 10mg/L and for oxipurinol 1 and 40 mg/L, respectively. The assay was linear over the concentration range of 0.5-10mg/L (allopurinol) and 1-40 mg/L (oxipurinol). Intra- and inter-day precision showed coefficients of variation <15% over the complete concentration range; accuracy was within 5% for allopurinol and oxipurinol. Endogenous purine-like compounds were separated from allopurinol, oxipurinol and aciclovir with a resolution factor >1.5. Exogenous purine-like compounds and co-medication frequently used by gout patients did not hinder the analysis due to the dichloromethane washing step or to low UV-absorpion at 253 nm. Serum levels of 66 patients prescribed allopurinol 300 mg/day were determined using this HPLC-UV method. Measured serum allopurinol and oxipurinol concentrations in clinical practice showed large variability with a range of <0.5-4.3 mg/L for allopurinol and <1.0-39.2 mg/L for oxipurinol, respectively. CONCLUSION: We developed an easy-to-operate and validated HPLC-UV method for the quantification of allopurinol and oxipurinol in human serum. This method was proven to be valid for samples of gout patients frequently using concomitant medications.

Biochemical effectiveness of allopurinol and allopurinol-probenecid in previously benzbromarone-treated gout patients.

In 2003, the uricosuric drug benzbromarone was withdrawn from the market. The first alternative drug of choice was the xanthine oxidase inhibitor allopurinol. The purpose was to (1) investigate the efficacy of allopurinol (standard dosage) compared with previous treatment with benzbromarone; and (2) investigate the combination therapy allopurinol-probenecid as an effective alternative treatment compared with previous benzbromarone treatment. A prospective, open study was carried out in a cohort of 51 gout patients who discontinued benzbromarone therapy because of market withdrawal. Patients were given 200-300 mg allopurinol (stage 1). When allopurinol failed to attain the target serum urate (sUr) levels

Leflunomide for the treatment of rheumatoid arthritis in clinical practice: incidence and severity of hepatotoxicity.

OBJECTIVE: Leflunomide is a novel disease modifying antirheumatic drug (DMARD). Because of reports on possible hepatotoxicity and adaptations in the recommendations for monitoring liver function during leflunomide treatment, we conducted a study to evaluate the incidence and severity of hepatotoxicity. METHODS: We included consecutive rheumatoid arthritis patients starting treatment with leflunomide in the region of Friesland (The Netherlands) between January 2000 and January 2002. During follow-up patient characteristics, disease characteristics, and clinical and laboratory data on liver functions were registered. Severity of hepatotoxicity was categorised using the National Cancer Institute Common Toxicity Criteria, as moderate (grade 2), severe (grade 3) or life threatening (grade 4). RESULTS: One hundred and one patients were followed for a median period of 10 months (range 0.5-12). Grade 2 or 3 elevations in any liver function blood test were recorded in a total of nine patients (8.9%). No grade 4 elevations were recorded. Four patients (4%) showed grade 2-3 aminotransferase elevations. Due to grade 2 hepatotoxicity one patient (1%) was withdrawn from leflunomide treatment, and one patient continued leflunomide at a reduced dose. In eight of nine patients with grade 2-3 liver function blood tests, these elevated liver function tests occurred within 6 months after starting leflunomide. None of the patients with grade 2 or 3 toxicity had a history of hepatic disease, eight patients concomitantly used potential hepatotoxic co-medication. Eight (8%) patients used leflunomide in combination with methotrexate, and one of these patients developed hepatotoxicity. No clinical signs of serious hepatotoxicity were recorded during follow-up. DISCUSSION: In 8.9% of the patients, grade 2 or 3 hepatotoxicity was recorded within the first year after the start of leflunomide therapy based on liver enzyme determinations. In the majority of the patients liver enzyme elevations occurred within the first 6 months of therapy and resolved during continued follow-up. None of the patients showed clinical signs of hepatotoxicity. CONCLUSION: Under continued monitoring of liver functions hepatotoxicity during leflunomide use does not seem to be a major problem in our population.