The alkalizer citrate reduces serum uric Acid levels and improves renal function in hyperuricemic patients treated with the xanthine oxidase inhibitor allopurinol.
OBJECTIVE
Hyperuricemia, an integral component of metabolic syndrome, is a major health problem causing gout and renal damage. Urine alkalizers such as citrate preparations facilitate renal excretion of the uric acid, but its supportive effect on xanthine oxidase inhibitors has not been tested yet. We performed a randomized, prospective study of the effect of a combination of allopurinol and a citrate preparation on renal function in patients with hyperuricemia, employing 70 patients who had hyperuricemia with serum uric acid levels ≥7.0 mg/dL, or those diagnosed as having hyperuricemia in the past.


METHODS
They were randomly enrolled into two study groups: the allopurinol monotherapy (MT) group or combination treatment (CT) group with allopurinol and a citrate preparation. Allopurinol (100-200 mg/day) in the absence or presence of a citrate preparation (3 g/day) was administered for 12 weeks and levels of serum uric acid, its urinary clearance (Cua), and the renal glomerular filtration rates assessed with the creatinine clearance (Ccr) were evaluated before and after the treatment.


RESULTS
Serum levels of uric acid decreased significantly in both groups, whereas the change observed was much greater in CT group. Cua was significantly increased in CT group but not in MT group. Ccr was not altered in both groups in general, whereas it was significantly increased in a fraction of CT group with decreased renal function.


CONCLUSIONS
These results indicate that an additional use of citrate preparations with xanthine oxidase inhibitors is beneficial for patients with hyperuricemia, reducing circulating uric acid and improving their glomerular filtration rates.
Division of Endocrinology and Metabolism, Department of Medicine, Yokohama Rosai Hospital, Yokohama, Japan. saitoj@yokohamah.rofuku.go.jp
Jun
J
Saito
Yoko
Y
Matsuzawa
Hiroko
H
Ito
Masao
M
Omura
Yuzuru
Y
Ito
Koichiro
K
Yoshimura
Yuki
Y
Yajima
Tomoshige
T
Kino
Tetsuo
T
Nishikawa
D000493:Allopurinol / Q000627:therapeutic use*; D019343:Citric Acid / Q000627:therapeutic use*; D003404:Creatinine / Q000652:urine; D004359:Drug Therapy, Combination; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006074:Gout Suppressants / Q000627:therapeutic use*; D006801:Humans; D033461:Hyperuricemia / Q000097:blood / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014527:Uric Acid / Q000097:blood*; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
D006074:Gout Suppressants; D014527:Uric Acid; D019343:Citric Acid; D000493:Allopurinol; D003404:Creatinine; D014969:Xanthine Oxidase