Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.
Adverse Reactions to Allopurinol Are Not Increased In Patients Exposed to Doses Higher Than Recommended for Creatinine Clearance: A Retrospective Study of A Large Urban Multispecialty Group.
Paisansinsup1, Tawatchai, Schousboe2, John T.
Reported recommendations of allopurinol dose adjustment based on creatinine clearance to reduce adverse reactions in patients with renal insufficiency were based on case reports1. The efficacy of this strategy is unproved with unintended consequences of suboptimal uric acid level and poor control of gout.
We identified 551 patients who had allopurinol prescribed between 1/1/2004 and 12/31/2010 who had their serum creatinine measured while on allopurinol and who had complete covariate data. Adverse drug reactions (ADRs) to allopurinol were defined as listing of allopurinol in the ADR list of the medical record or as a physician's attribution of an adverse event to allopurinol combined with discontinuation of the drug. Patient charts were individually reviewed to adjudicate the accuracy of the reported ADRs and the reasons for prescription discontinuation. ADRs were categorized as major (severe cutaneous reactions and/or resulted in death) or minor. Each person's exposure to allopurinol was estimated to be above or below that recommended by Hande, et al1 according to their creatinine clearance. The association of minor or major ADRs to allopurinol with use of allopurinol in doses above recommendation was estimated with logistic regression models.
Prescribed allopurinol doses ranged from an average of 50 mg/day to 750 mg/day (mean and median, respectively, 227 and 300 mg/day). Mean creatinine clearance (Cockcroft-Gault) was 57 ml/min (range 8.5 to 125 ml/min). Three hundred forty two patients (61.5%) were prescribed doses that exceeded those recommended for their levels of renal function; 65 patients (11.7%) had a minor ADR and none had a major ADR to allopurinol. The odds ratio of an allopurinol ADR in those exposed to allopurinol doses higher than recommended for their levels of renal function compared to those treated with doses within or below the recommended dose was 0.84 (95% C.I. 0.49 to 1.46) adjusted for age, sex, diabetes mellitus, ischemic heart disease, hypertension, use of diuretics, and use of aspirin.
The risk of having ADRs to allopurinol is not increased in patients exposed to allopurinol doses higher than those recommended by Hande, et al1. These results support the strategy of titrating doses of allopurinol to attain a therapeutic goal of uric acid below 6 mg/dl to achieve adequate clinical control of gout.
To cite this abstract, please use the following information:
Paisansinsup, Tawatchai, Schousboe, John T.; Adverse Reactions to Allopurinol Are Not Increased In Patients Exposed to Doses Higher Than Recommended for Creatinine Clearance: A Retrospective Study of A Large Urban Multispecialty Group. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :1036