Drug-induced gout

Risk of gout flare after medication: prescription symmetry sequence analysis

OBJECTIVES

The research aimed to study the following questions: (1) five well-known gout-related medications were selected to test the validity of the prescription symmetry sequence analysis in Taiwan; (2) four exploratory medications were selected to test their relation to gout flares.

METHODS

We utilized the 2003-2017 dataset of the Taiwan National Health Insurance Program containing all claims data with 2 million beneficiaries as a data source. In order to explore the temporal association, we designed a scenario of medication-induced gout flares. Nine medications were selected as the index agent, including aspirin (low-dose), thiazide diuretics, loop diuretics, ethambutol, pyrazinamide, metformin, pioglitazone, fenofibrate, and losartan. The gout flare was defined as subjects with use of the marker agent for treatment of gout flares. The observation-window period between initiation of the index agent and initiation of the marker agent was 1 year. Subjects who used an index agent and a marker agent on the same day were excluded. The prescription symmetry sequence analysis was carried out to compare the observed number of persons who took an index agent prior to starting a marker agent with the observed number of persons who took a marker agent before starting an index agent. The adjusted sequence ratio (adjusted SR) with 95% confidence interval was applied to estimate the relation between an index agent and the marker agent.

RESULTS

Among five medications including aspirin (low-dose), thiazide diuretics, loop diuretics, ethambutol, and pyrazinamide, the adjusted sequence ratio ranged from 1.15 to 3.35 and all reached statistical significance. Fenofibrate use and losartan use were associated with a lower probability of gout flares, with reaching statistical significance (adjusted SR = 0.60 for fenofibrate and adjusted SR = 0.92 for losartan). Metformin use was associated with a greater probability of gout flares, with reaching statistical significance (adjusted SR = 1.14). Pioglitazone use did not reach statistical significance.

CONCLUSION

Based on the confirmatory analysis including five well-known gout-related medications, this study supports that the prescription symmetry sequence analysis can be used to detect an adverse drug event associated with one potential offending agent. The exposure to fenofibrate or losartan might be a protective factor against gout flares. Metformin use could be associated with a greater probability of gout flares, but this finding should be validated by other studies.

KEY POINTS

• What is already known about this subject? 1. The prescription symmetry sequence analysis is a useful method for detecting an adverse drug reaction associated with one potential offending drug. 2. Numerous medications are found to induce gout flares. • What does this study add? 1. The prescription symmetry sequence analysis supports the evidence that aspirin (low-dose), thiazide diuretics, loop diuretics, ethambutol and pyrazinamide are associated with a greater probability of gout flares. 2. The exposure to fenofibrate or losartan might be a protective factor against gout flares. 3. Metformin use could be associated with a greater probability of gout flares. • How might this impact on clinical practice or future developments? 1. Clinicians should always consider the possibility of medication-induced gout flares. If gout flares develop, discontinuation of risky medications is the first step. Then prescribing cascades can be eliminated.

Gout in an Obese Patient with Nonalcoholic Steatohepatitis on a Thiazide Diuretic and Association Between Hyperuricemia and Nonalcoholic Steatohepatitis: A Case Report

Gout is a common inflammatory arthritis caused by increased uric acid crystals in and around various joints, mainly the big toe in adults. It happens due to the increase of urate or uric acid levels either because of increased production or decreased excretion from the body. Uric acid is the final product of purine metabolism, and many patients with hyperuricemia may remain asymptomatic. We present a case of a 46-year-old male who presented to the ambulatory care unit with the clinical features of acute pharyngitis and left toe pain for the past three days. On further questioning, he added that he had pain in the left lumber region and left side of the toe for the past few months. He also had a known case of type 2 diabetes mellitus, hypertension, and gastritis, for which he has been taking the thiazide diuretic, angiotensin-converting enzyme (ACE) inhibitors, metformin, sitagliptin, aspirin, and atorvastatin. Laboratory tests showed elevated uric acid along with raised inflammatory markers. As a result, he was referred to the specialist for arthrocentesis in order to confirm the diagnosis, and the thiazide diuretic was replaced with calcium channel blockers. He also suffered from nonalcoholic steatohepatitis (NASH) based on his ultrasound abdomen. On the follow-up visit, his symptoms had resolved, and his uric acid level had normalized.

Pathophysiology of hyperuricemia and its clinical significance - a narrative review

Hyperuricemia, i.e. increased serum uric acid (UA) concentration, is a common problem in clinical practice. While there are clear guidelines concerning management of symptomatic hyperuricemia in acute conditions such as gout, urolithiasis or acute urate nephropathy, less is known about their secondary prevention. Moreover, despite the ongoing debate on the role of UA in the pathogenesis of chronic kidney disease, hypertension, cardiovascular disease and heart failure, the management of asymptomatic hyperuricemia in patients with these chronic conditions is still mainly up to physicians' judgement. Individual considerations should always be taken into account when prescribing urate-lowering therapy. In this narrative review study, we attempt to present current trends concerning treatment of patients with either symptomatic or asymptomatic hyperuricemia in the light of the available knowledge on the role of hyperuricemia in the development of gout, renal, cardiovascular and other diseases.

Research Advances in the Mechanisms of Hyperuricemia-Induced Renal Injury

Uric acid is the end product of purine metabolism in humans, and its excessive accumulation leads to hyperuricemia and urate crystal deposition in tissues including joints and kidneys. Hyperuricemia is considered an independent risk factor for cardiovascular and renal diseases. Although the symptoms of hyperuricemia-induced renal injury have long been known, the pathophysiological molecular mechanisms are not completely understood. In this review, we focus on the research advances in the mechanisms of hyperuricemia-caused renal injury, primarily on oxidative stress, endothelial dysfunction, renal fibrosis, and inflammation. Furthermore, we discuss the progress in hyperuricemia management.

Musculoskeletal manifestations of tuberculosis: An observational study

Background:

Data of musculoskeletal manifestations of tuberculosis (TB) are limited to case reports, series, or retrospective studies. Therefore, we conducted this study to create awareness among doctors about musculoskeletal manifestations of TB.

Materials and Methods:

This was a prospective observational study conducted at a referral TB Hospital in North India in September and October 2016. The aim of our study was to study musculoskeletal manifestations of TB. We included patients who had active TB as per the World Health Organization 2010 criteria. Patients with other chronic illnesses were excluded. A detailed history, examination, and appropriate investigations (blood, urine, serological, and radiological) of the 100 consecutive patients fulfilling the inclusion criteria were recorded.

Results:

The mean age of patients was 32.16 ± 12.93 years. Male-to-female ratio was 43:57. The mean duration of disease was 6.85 ± 8.83 months. Of the 100 patients, 60 (60%) had pulmonary TB. The mean duration of antitubercular therapy was 1.79 ± 1.34 months. Fibromyalgia was classified in 21 (21%) patients, polyarthralgia was seen in 9 (9%), Pott's spine in 7 (7%), osteomyelitis in 4 (4%), and scleritis in 2 (2%) patients. Uveitis, tenosynovitis, erythema induratum, subcutaneous abscess, and dactylitis were seen in 1 (1%) patient each. In 21 patients who had fibromyalgia, 11 developed fibromyalgia with the second episode of TB amounting to 60.75% patients.

Conclusion:

This is the first prospective study to look at the musculoskeletal manifestations of TB. Patients with active TB were found to have various rheumatological manifestations.

Relationship between Hyperuricemia and Haar-Like Features on Tongue Images

Objective. To investigate differences in tongue images of subjects with and without hyperuricemia. Materials and Methods. This population-based case-control study was performed in 2012-2013. We collected data from 46 case subjects with hyperuricemia and 46 control subjects, including results of biochemical examinations and tongue images. Symmetrical Haar-like features based on integral images were extracted from tongue images. T-tests were performed to determine the ability of extracted features to distinguish between the case and control groups. We first selected features using the common criterion P < 0.05, then conducted further examination of feature characteristics and feature selection using means and standard deviations of distributions in the case and control groups. Results. A total of 115,683 features were selected using the criterion P < 0.05. The maximum area under the receiver operating characteristic curve (AUC) of these features was 0.877. The sensitivity of the feature with the maximum AUC value was 0.800 and specificity was 0.826 when the Youden index was maximized. Features that performed well were concentrated in the tongue root region. Conclusions. Symmetrical Haar-like features enabled discrimination of subjects with and without hyperuricemia in our sample. The locations of these discriminative features were in agreement with the interpretation of tongue appearance in traditional Chinese and Western medicine.

The association between shift work and hyperuricemia in steelmaking male workers

Objectives

The aim of this study was to examine the association between shift work and hyperuricemia among steel company workers.

Methods

We examined 1,029 male workers at a Korean steel company between June 6 and June 28, 2013. We conducted anthropometric measurements, questionnaire surveys, and blood tests. Hyperuricemia was defined as a serum uric acid concentration of ≥7.0 mg/dL. Logistic regression analyses were performed. In the full model, analysis was adjusted for covariates including age, body mass index, lifestyle factors, and comorbidities. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for all models.

Results

The participants included 276 daytime workers and 753 shift workers. Among daytime workers, 72 (26.1%) individuals had hyperuricemia, as did 282 (37.5%) individuals among shift workers (p <0.001). There was a statistically significant association between shift work and hyperuricemia. In the unadjusted model, the OR of shift work was 1.70 (95% CI 1.25-2.31) for hyperuricemia. In the full model, the OR of shift work was also statistically significant after adjustment for covariates (OR 1.41, 95% CI 1.02-1.96).

Conclusions

Among male steel workers, a significant association between shift work and hyperuricemia was observed.

Drug-induced arthritic and connective tissue disorders

OBJECTIVES

All pharmacologic agents have the potential for both benefit and toxicity. Among the more interesting and important adverse consequences of drug therapy are a range of joint and connective tissue complaints that may mimic or reproduce primary rheumatologic diseases. In this article, we review the literature on commonly used drugs reported to induce arthritis and/or connective tissue-based diseases. We assess the strength of the reported associations, discuss diagnostic features and treatment implications, and consider possible mechanisms for drug-induced genesis of rheumatic conditions.

METHODS

We reviewed the Medline database from 1987 to 2006 to identify drug-induced arthritic and connective-tissue disease syndromes, utilizing 48 search terms. A qualitative review was performed after the articles were abstracted and the relevant information was organized.

RESULTS

Three hundred fifty-seven articles of possible relevance were identified. Two hundred eleven publications were included in the final analysis (case series and reports, clinical trials, and reviews). Many drugs were identified as mimicking existing rheumatic conditions, including both well-established small molecules (eg, sulfasalazine) and recently introduced biologic agents (eg, antitumor necrosis factor agents). The most commonly reported drug-induced rheumatic conditions were lupus-like syndromes. Arthritis and vasculitis were also often reported.

CONCLUSIONS

Drug-induced rheumatic syndromes are manifold and offer the clinician an opportunity to define an illness that may remit with discontinuation of the offending agent. Early diagnosis and withdrawal of the drug may prevent unnecessary morbidity and disability.

The ever-expanding association between rheumatologic diseases and tuberculosis

We summarized most of the rheumatologic manifestations of tuberculosis (TB) and the occurrence of Mycobacterium tuberculosis disease associated with rheumatologic diseases. We established 4 different categories: (1) direct musculoskeletal involvement of M. tuberculosis, including spondylitis, osteomyelitis, septic arthritis, and tenosynovitis; (2) M. tuberculosis as an infectious pathogen in rheumatologic diseases, particularly with the use of newer agents such as tumor necrosis factor-alpha inhibitors; (3) antimycobacterial drug-induced rheumatologic syndromes, including tendinopathy, drug-induced lupus, and others; and (4) reactive immunologic phenomena caused by TB, such as reactive arthritis, erythema nodosum, and others. In addition, Bacille-Calmette-Guérin vaccination used for the prevention of TB or as a chemotherapeutic agent for bladder carcinoma also may be associated with musculoskeletal adverse events. We conclude that M. tuberculosis can directly or indirectly affect the musculoskeletal system.

Pathophysiology, Clinical Presentation and Treatment of Gout

Gout is a common form of inflammatory arthritis that has been managed primarily in general medical practices for centuries. It appears that there has been an increasing prevalence of gout over the past decades, implying a growing public health burden. Accurate diagnosis and recognition of the various stages and manifestations of gout enable realistic goal setting for management. Recent evidence suggests new risk factors and potentially refutes others. Management of gout requires characterising and modifying risk factors and associated disorders, and commonly initiating drug therapy. Pharmacotherapy of gout includes the management of acute flares with anti-inflammatory agents such as NSAIDs and glucocorticoids and long-term treatment with urate-lowering drugs. Although pharmacotherapy is generally safe and effective, there are caveats and limitations to all gout therapies. Patient non-adherence and errors with the use of drugs for gout treatment are important factors leading to medical failures. With early intervention, careful monitoring and patient education, gout is a condition that can be managed very effectively. The advent of new drugs (such as febuxostat and urate oxidase [uricase]) and enhanced understanding of the pathogenesis of gout continue to improve our therapeutic options, particularly in a subset of patients with refractory disease and those who are intolerant to currently available medications.

An update on the treatment options for gout and calcium pyrophosphate deposition

Gout and calcium pyrophosphate deposition disease are two common causes of inflammatory joint disease. Despite differences underlying their pathogenesis, their clinical presentation and treatment share some common features. Optimal treatment for both requires prompt resolution of acute synovitis, reduction of chronic joint damage and management of associated conditions. Available therapeutic interventions and future strategies are reviewed in this article.

Drug Therapy in Transplant Recipients

Elderly patients with end-stage organ failure are now more frequently undergoing transplantation. Medication management in this population is challenging because of the combination of multiple comorbidities, polypharmacy, and immunological, pharmacokinetic and pharmacodynamic changes attributable to the aging process. Immunosuppressive medications can exacerbate pre-existing medical conditions and promote the development of disease processes. Cardiovascular disorders, such as hypertension, coronary artery disease, congestive heart failure and arrhythmias are common in elderly transplant recipients, and account for most of the deaths in this population. Blood pressure, blood glucose and cholesterol control is of particular concern because elderly transplant recipients frequently have or develop these complications. Elderly transplant recipients are commonly receiving anticoagulation therapy with warfarin and are at a higher risk of bleeding, especially if they have renal dysfunction. Infectious complications occur frequently in the transplanted population, with pneumonia being the most common infection seen in hospitalised patients. Attention to vaccination for the prevention of influenza and pneumococcal infections is important because of the increased risk of these diseases in this population. Depression itself has been associated with decreased survival in older individuals, and depression in elderly transplant recipients may be reversible with the administration of pharmacological agents. Effective long-term care of transplant recipients demands an understanding of how particular medications affect clinical evaluation and treatment. This article addresses some of the practical issues surrounding medication management and prevention of these particular problems in elderly transplant recipients.

Drug-induced rheumatic disorders: incidence, prevention and management

The purpose of this article is to review the causes, the clinical manifestations and the management of the more frequent drug-induced rheumatic disorders. These include: (i) articular and periarticular manifestations induced by fluoroquinolones, nonsteroidal anti-inflammatory drugs, injections of corticosteroids, and retinoids; (ii) multisystemic manifestations such as drug-induced lupus and arthritis induced by vaccination, Bacillus Calmette-Guerin therapy and cytokines; (iii) drug-induced disorders of bone metabolism (corticosteroid-induced osteoporosis, drug-induced osteomalacia and osteonecrosis); and (iv) iatrogenic complex regional pain syndromes. Disorders caused by nonpharmacological and rarely used treatments have been deliberately excluded. Knowledge of these drug-induced clinical symptoms or syndromes allows an earlier diagnosis and treatment, and earlier drug withdrawal if necessary. With the introduction of new medications such as the recombinant cytokines and antiretroviral treatments, the number of drug-induced rheumatic disorders is likely to increase.

Pharmacokinetic factors in the modern drug treatment of tuberculosis

Tuberculosis is increasing in prevalence throughout the world, particularly in sub-Saharan Africa, Asia and Latin America. This resurgence can partly be attributed to increasing poverty, particularly in developing countries, and the human immunodeficiency virus (HIV) pandemic. However, there is also increasing concern at the development of multidrug-resistant tuberculosis caused by the misuse of the agents available. The modern treatment of patients with tuberculosis should start, in most cases, with 4 first-line agents in order to minimise the risk of drug resistance developing. A6-month drug regimen is usually satisfactory for pulmonary and nonpulmonary tuberculosis, although not for patients with tuberculous meningitis, in whom a longer course of treatment is required. Coinfection with HIV may produce an atypical clinical and radiological presentation, but the treatment regimen is essentially similar to other situations. Several of the first-line agents, in particular rifampicin (rifampin) and isoniazid, are likely to cause clinically significant drug interactions and/or toxicity, particularly in patients with HIV infection. Consideration of the pharmacodynamic and pharmacokinetic interactions between the host, the mycobacterium and the drug may contribute to the development of pharmacokinetically optimised regimens that make best use of the existing range of antituberculosis drugs. However, such idealised regimens need to be tested in prospective clinical trials. The use of therapeutic drug monitoring in selected groups of patients may improve outcomes, avoid drug toxicity and reduce the development of multidrug-resistant tuberculosis. The management of multidrug-resistant tuberculosis requires a high level of clinical expertise and such patients should start on at least 5 drugs to which the organism is thought to be susceptible. Up to 50% of patients with tuberculosis may not adhere to their drug regimen, resulting in persisting infectiousness, relapse or the development of drug resistance. Directly observed treatment with antituberculosis drugs, combined with a serious commitment to tuberculosis control, is required if we are to combat this increasing epidemic.

Effects of acipimox on haemorheology and plasma lipoproteins in patients with mixed hyperlipoproteinaemia

AIMS

Epidemiological data have shown that haemorheological disorders are associated with an increased risk of atherosclerosis. We evaluated the effect of the nicotinic acid derivative acipimox on haemorheological and lipid parameters in 18 patients with mixed hyperlipoproteinaemia using a randomized, double-blind, placebo-controlled, cross-over study protocol.

METHODS

Patients (7 women, 11 men, aged 49.3+/-3.0 years) were investigated with acipimox (dose adjusted to weight, 500 or 750 mg daily) compared with placebo treatment each for 12 weeks. Lipid parameters, whole blood viscosity, plasma viscosity, fibrinogen, and red cell aggregation at native and standardized (0.45) haematocrit as well as red cell filterability were measured at baseline, at week 12 (change of therapy), and at week 24.

RESULTS

Total cholesterol concentration (8.30+/-0.32 vs 8.72+/-0.36 mmol/l(-1)) and apolipoprotein B (198.5+/-9.9 vs 217+/-9.9 mg dl(-1)) were significantly lower (P<0.05) during acipimox therapy compared with placebo, no significant changes were observed for triglycerides and low-density lipoprotein [LDL] cholesterol. However, total high-density lipoprotein [HDL] cholesterol (1.24+/-0.05 vs 1.10+/-0.05 mmol l(-1), P<0.001) as well as HDL2 and HDL3 cholesterol (P<0.05) were significantly higher during acipimox therapy. The LDL cholesterol to HDL cholesterol ratio significantly improved during acipimox therapy (4.63+/-0.25 vs 5.49+/-0.26, P<0.001). Red cell aggregation at native and standardized haematocrit were the only haemorheological parameters which improved during acipimox therapy in comparison with placebo (shear rate 3 s(-1):10.69+/-0.40 vs 11.50+/-0.44 U, P<0.05, for native red cell aggregation; 10.40+/-0.36 vs 11.28+/-0.39 U, P<0.05, for standardized red cell aggregation).

CONCLUSIONS

We conclude, that the cardiovascular risk profile improves during acipimox therapy due to an elevation in HDL cholesterol and its subfractions as well as a decrease in red cell aggregation.

Effect of theophylline on serum uric acid levels in children with asthma

This study was undertaken to investigate the effect of theophylline on serum uric acid levels in children with asthma. Twenty-seven asthmatic children, including 21 patients who were treated with slow-release theophylline and 6 patients not receiving any type of theophylline preparation, were enrolled in this study. Serum uric acid levels were increased in the asthmatic children treated with theophylline compared to those not receiving this agent (6.28 +/- 0.29 mg/dl, mean +/- SEM, vs. 4.82 +/- 0.52 mg/dl, p < 0.05). A significant positive correlation between the serum levels of uric acid and theophylline was demonstrated in the patients of this study (rs = 0.596, p < 0.01). All the patients in whom theophylline administration was stopped showed significant decreases in serum uric acid levels (p < 0.05). From these results, we conclude that theophylline increases serum uric acid levels in children with asthma, just as it does in adult asthmatics.

Diuretic induced gout: a multifactorial condition

Fifteen patients with clinical gout occurring after long term treatment with diuretics were studied retrospectively. In all 15 patients one or more additional factors were present which might have contributed to the hyperuricaemia and gout. The most common of these was the impairment of the glomerular filtration rate. Twenty five other patients receiving long term treatment with diuretics who did not have gout were also studied. The concentrations of uric acid, urea, and creatinine were, in general, markedly lower in these patients than in those who had developed gout. It is concluded that diuretic induced gout occurs in patients in whom there is an additional cause of hyperuricaemia, usually impaired renal function.