563 COMPARISON OF EFFECTS OF LOSARTAN 50 MG/HYDROCHLOROTHIAZIDE 12.5 MG AND CANDESARTAN 8 MG/ HYDROCHLOROTHIAZIDE 6.25 MG ON PLASMA LEVELS AND URINARY EXCRETION OF URIC ACID IN JAPANESE HYPERTENSIVE PATIENTS WITH TYPE 2 DIABETES MELLITUS

Abstract

Background and Objective: To see effects of losartan and hydrochlorothiazide (HCTZ) on uric acid metabolism, Methods: In patients with hypertension and type 2 diabetes mellitus who have already received a combination therapy with losartan 50 mg plus hydrochlorothiazide (HCTZ) 12.5 mg (Preminent®) and their blood pressure (BP) was controlled to < 130/80 mmHg, antihypertensive drug was switched to candesartan 8 mg plus HCTZ 6.25 mg (Ecard HD®) for 2 months and then switched back to Preminent®) for another 2 months. Results: BP was not altered between two regimens. However, plasma levels of uric acid (UA) was increased from 5.5 ± 1.2 (SD) to 5.9 ± 1.3 (p = 0.108) after changing to Ecard HD®), and then returned to 5.5 ± 1.2 mg/dl after switching back to Preminent®) (p = 0.017). Urinary excretion of UA (corrected by creatinine) was decreased from 0.54 ± 0.25 to 0.47 ± 0.20 (p = 0.046) after changing to Ecard HD®, and then returned to 0.66 ± 0.49 after switching back to Preminent®)(p = 0.038). Conclusions: Based on losartan's inhibitory action on UA reabsorption via URAT-1, these results suggest that an ability of 50 mg of losartan to decrease plasma UA level might be greater than that of 6.25 mg (the difference between two regimens) of HCTZ to increase plasma UA level, indicating that taking such a small difference of the amount of HCTZ into consideration for the treatment of hypertensive patients, especially associated with hyperuricemia and/or chronic kidney disease, is very important.