In older adults, new use of allopurinol or febuxostat was linked to hypersensitivity reactions versus colchicine.

SOURCE CITATION: Singh JA, Cleveland JD. Hypersensitivity reactions with allopurinol and febuxostat: a study using the Medicare claims data. Ann Rheum Dis. 2020;79:529-35. 32024648.

Association between long-term prescription of febuxostat and the progression of heart failure with preserved ejection fraction in patients with hypertension and asymptomatic hyperuricemia.

Both hypertension and hyperuricemia are closely associated with the morbidity and mortality of heart failure. This study was designed to evaluate the influences of long-term xanthine oxidase inhibitor (febuxostat) prescription on left ventricular hypertrophy (LVH), left ventricular (LV) diastolic function, and new-onset heart failure with preserved ejection fraction (HFpEF) in these patients. Using a propensity score matching of 1:2 ratio, this retrospective claims database study compared febuxosatat prescription (n = 96) and non-urate-lowering therapy (n = 192) in patients with hypertensive left ventricular hypertrophy (LVH) and asymptomatic hyperuricemia. With a follow-up of 36 months, febuxostat significantly decreased the level of serum uric acid as well as generated more prominent improvement in LVH and LV diastolic function. Besides, the new-onset symptomatic HFpEF occurred in 2 of 96 patients in febuxostat group and 13 of 192 patients in non-urate-lowering group (P = 0.091). No increased risk for major adverse cardiovascular events in patients prescribed with febuxostat was noted. In conclusion, long-term febuxostat exposure was associated with protective effects in terms of LVH or LV diastolic dysfunction in patients with hypertensive LVH and asymptomatic hyperuricemia. Febuxostat also displayed a trend for reduced risk of new-onset HFpEF in this population.

Cardiovascular events in hyperuricemia population and a cardiovascular benefit-risk assessment of urate-lowering therapies: a systematic review and meta-analysis.

BACKGROUND: Hyperuricemia and gout have become public health concerns; many important guidelines have recommended xanthine oxidase inhibitors (XOIs) as the first-line urate-lowering therapies (ULTs) to treat chronic gout with hyperuricemia. However, whether treating hyperuricemia and gout with ULTs modifies cardiovascular risks remains controversial. The aim of this study was to assess the incident risk of cardiovascular (CV) events (CVE) in hyperuricemia population, assess the cardiovascular benefit-risk of ULTs in hyperuricemia patients with or without gout in diverse cardiovascular risk sub-groups, and specify the safety of different ULTs. METHODS: We searched PubMed, Embase, the Cochrane Library, Wanfang, Chongqing VIP (CQVIP, en.cqvip.com), and China National Knowledge Infrastructure Database for prospective cohort studies and randomized controlled trials (RCTs) in English and Chinese. Potential medications included XOIs, and uricosurics. RCTs were divided into sub-groups analysis based on blinding status and patients' history of CV diseases. Risk ratios (RRs) were calculated and were reported with corresponding 95% confidence intervals (CIs) by fixed-effects or random-effects model. RESULTS: Seven prospective cohort studies and 17 RCT studies were included. The risks of both major adverse cardiovascular events (MACE) (RR = 1.72, 95% CI 1.28-2.33) and CVE (RR = 1.35, 95% CI 1.12-1.62) were higher in the hyperuricemia population than non-hyperuricemia one. In seven RCT studies where XOIs were compared with no-treatment or placebo, the results of five low CV risk studies showed that XOIs lowered the risks of both MACE (RR = 0.35, 95% CI 0.20-0.62) and CVE (RR = 0.61, 95% CI 0.44-0.85); whereas two high CV risk studies showed that XOIs lowered the risk of CVE (RR = 0.69, 95% CI 0.54-0.88) rather than MACE (RR = 0.62, 95% CI 0.29-1.35). In nine RCT studies where the cardiovascular safety between febuxostat and allopurinol were compared, no statistical difference was found in the risk of MACE or CVE. CONCLUSIONS: The hyperuricemia population does have a higher incidence of CVE, and the results suggested that XOIs might reduce the incidence of MACE and total CVE. In addition, from the perspective of cardiovascular safety, febuxostat equaled allopurinol in our meta-analysis.

Hypersensitivity reactions with allopurinol and febuxostat: a study using the Medicare claims data.

OBJECTIVE: To assess the risk of hypersensitivity reactions (HSRs) with allopurinol and febuxostat in a population-based study. METHODS: We used the 5% Medicare beneficiary sample (≥65 years) from 2006 to 2012 to identify people with a newly filled prescription for allopurinol, febuxostat or colchicine. We used multivariable-adjusted Cox regression analyses to compare the hazard ratio (HR) of incident HSRs with allopurinol or febuxostat use versus colchicine use; separate analyses were done in people exposed to allopurinol. Propensity-matched analyses (5:1) compared hazards with allopurinol versus febuxostat. RESULTS: Crude incidence rates of HSRs were as follows: allopurinol, 23.7; febuxostat, 30.7; and colchicine, 25.6 per 1000 person-years. Compared with colchicine, allopurinol, febuxostat and febuxostat+colchicine were associated with significantly higher HRs of HSRs, 1.32 (95% CI: 1.10 to 1.60) and 1.54 (95% CI: 1.12 to 2.12) and 2.17 (95% CI: 1.18 to 3.99), respectively. In propensity-matched analyses, febuxostat did not significantly differ from allopurinol; HR for HSRs was 1.25 (95% CI: 0.93 to 1.67). Compared with allopurinol start dose <200 mg/day, allopurinol start dose ≥300 mg/day, diabetes and female sex were associated with significantly higher hazard of HSRs, 1.27 (95% CI: 1.12 to 1.44), 1.21 (95% CI: 1.00 to 1.45) and 1.32 (95% CI: 1.17 to 1.48), respectively. The majority (69%) of HSRs occurred in the outpatient setting. CONCLUSIONS: Compared with colchicine, allopurinol and febuxostat similarly increased the risk of HSRs. Allopurinol and febuxostat did not differ from each other. In allopurinol users, starting dose, female sex and diabetes increased this risk, findings that need further study.

Assessment of Cardiovascular Risk in Older Patients With Gout Initiating Febuxostat Versus Allopurinol: Population-Based Cohort Study.

BACKGROUND: Hyperuricemia and gout are associated with an increased risk of cardiovascular disease. Xanthine oxidase inhibitors, allopurinol and febuxostat, are the mainstay of urate-lowering treatment for gout and may have different effects on cardiovascular risk in patients with gout. METHODS: Using US Medicare claims data (2008-2013), we conducted a cohort study for comparative cardiovascular safety of initiating febuxostat versus allopurinol among patients with gout ≥65 years of age. The primary outcome was a composite end point of hospitalization for myocardial infarction or stroke. Secondary outcomes were individual end points of hospitalization for myocardial infarction, stroke, coronary revascularization, new and recurrent heart failure, and all-cause mortality. We used propensity score matching with a ratio of 1:3 to control for confounding. We estimated incidence rates and hazard ratios for primary and secondary outcomes in the propensity score-matched cohorts of febuxostat and allopurinol initiators. RESULTS: We included 24 936 febuxostat initiators propensity score-matched to 74 808 allopurinol initiators. The median age was 76 years, 52% were male, and 12% had cardiovascular disease at baseline. The incidence rate per 100 person-years for the primary outcome was 3.43 in febuxostat and 3.36 in allopurinol initiators. The hazard ratio for the primary outcome was 1.01 (95% CI, 0.94-1.08) in the febuxostat group compared with the allopurinol group. Risk of secondary outcomes including all-cause mortality was similar in both groups, except for a modestly decreased risk of heart failure exacerbation (hazard ratio, 0.94; 95% CI, 0.91-0.99) in febuxostat initiators. The hazard ratio for all-cause mortality associated with long-term use of febuxostat (>3 years) was 1.25 (95% CI, 0.56-2.80) versus allopurinol. Subgroup and sensitivity analyses consistently showed similar cardiovascular risk in both groups. CONCLUSIONS: Among a cohort of 99 744 older Medicare patients with gout, overall there was no difference in the risk of myocardial infarction, stroke, new-onset heart failure, coronary revascularization, or all-cause mortality between patients initiating febuxostat compared with allopurinol. However, there seemed to be a trend toward an increased, albeit not statistically significant, risk for all-cause mortality in patients who used febuxostat for >3 years versus allopurinol for >3 years. The risk of heart failure exacerbation was slightly lower in febuxostat initiators.

Design and Rationale for the Veterans Affairs "Cooperative Study Program 594 Comparative Effectiveness in Gout: Allopurinol vs. Febuxostat" Trial.

BACKGROUND: Gout patients do not routinely achieve optimal outcomes related in part to suboptimal administration of urate lowering therapy (ULT) including first-line xanthine oxidase inhibitors allopurinol or febuxostat. Studies leading to the approval of febuxostat compared this agent to allopurinol in inappropriately low, fixed doses. We will compare allopurinol with febuxostat in gout using appropriately titrated doses of both agents and a "treat-to-target" strategy congruent with specialty guidelines. METHODS: We have planned and initiated the Veterans Affairs (VA) Cooperative Study Program (CSP) 594, Comparative Effectiveness in Gout: Allopurinol vs Febuxostat study. This large double-blind, non-inferiority trial will enroll 950 gout patients randomized to receive allopurinol or febuxostat. Patients will be followed for a total of 72 weeks encompassing 3 distinct 24-week study phases. During Phase I (0-24 weeks), participants will undergo gradual dose titration of ULT until achievement of serum uric acid (sUA) <6.0 mg/dL or <5.0 mg/dL if tophi are present. Dose escalation will not be allowed during final three study visits of Phase 2 (24-48 weeks) and during Phase 3 (48-72 weeks). The primary study outcome is the proportion of participants experiencing at least one gout flare during Phase 3. Subsequent to the 72-week study, participants will be followed passively for up to 10 years after the study to assess long-term health outcomes. CONCLUSION: With its completion, the VA Comparative Effectiveness in Gout: Allopurinol vs Febuxostat study will demonstrate the central role of gradual ULT dose escalation and a treat-to-target strategy in gout management.