THIAZIDE DIURETICS AND THE INITIATION OF ANTIGOUT THERAPY

While physiologic and epidemiologic evidence link diuretic therapy wit h hyperuricemia, no previous study has quantified the risk for initiat ion of treatment specific for hyperuricemia or gout among elderly pati ents taking thiazide diuretics. We performed a retrospective cohort st udy of 9249 enrollees aged 65 or older in the New Jersey Medicaid prog ram who were newly started on an antihypertensive medication from Nove mber 1981 through February 1989 and who had no prior use of anti-gout therapy (allopurinol, colchicine, or a uricosuric) during the precedin g one-year period. We used Cox proportional hazards analysis to determ ine the risk for the initiation of and gout therapy in patients using various antihypertensive treatment regimens relative to no antihyperte nsive exposure. Patient follow-up extended for up to two years. Antihy pertensive exposure was characterized over the entire period of follow -up according to the following categories: thiazide diuretic therapy a lone; non-thiazide antihypertensive therapy; thiazide diuretic therapy in combination with any non-thiazide antihypertensive agent(s); and n o antihypertensive use. Antihypertensive exposure was entered into the model as a time-varying covariate. Estimates of risk were adjusted fo r age, sex, race, nursing home residence, number of prescriptions fill ed, intensity of physician use, hospitalization history, and year of a ntihypertensive treatment initiation. The adjusted relative risk for t he initiation of anti-gout therapy was 1.00 (95% CI, 0.65-1.53) for no n-thiazide antihypertensive therapy alone, 1.99 (95% CI, 1.21-3.26) fo r thiazide diuretic therapy, and 2.29 (95% CI, 1.55-3.37) for thiazide diuretic therapy in combination with any non-thiazide agent(s). Risk for antigout therapy was significantly increased for thiazide doses of greater than or equal to 25 mg/day (in hydrochlorothiazide equivalent s); no significant increase in risk was seen for lower doses. We concl ude that use of thiazide diuretics in doses of 25 mg/day or higher is associated with a significantly increased risk for initiation of anti- gout therapy. Such treatment may reflect the occurrence of clinical se quelae of diuretic-induced hyperuricemia or the inappropriate treatmen t of asymptomatic hyperuricemia. (C) 1997 Elsevier Science Inc.