The Effect of Allopurinol on Urinary Oxalate Excretion in Stone Formers

Abstract

Allopurinol is a drug which could be valuable in the treatment of stone patients. In 29 subjects treated with 300 mg of the drug per day it has been found that there was a significant fall in urine oxalate excretion if the blood urate was above 330 mumol/l. In 10 subjects followed for 1 year the urine oxalate was significantly reduced and maintained at a lower level than the original.

Urinary Oxalate Levels are not Affected by Dietary Purine Intake or Allopurinol

“…In summary, these studies demonstrate that the correlation between dietary purine and urinary oxalate levels shown earlier by ourselves and others (Zarembski and Hodgkinson, 1969;Scott et al, 1978;Simmonds et al, 1981) is more likely to be the consequence of the effect of a number of factors on the in uitro assay technique than a metabolic phenomenon in viuo. These studies also indicate that by reducing urine urate and uric acid excretion, allopurinol could benefit a small group of "hyperuricosuric calcium oxalate" stone formers.…”

“…An increment in urinary oxalate excretion following dietary purine loading was first noted by Zarembski and Hodgkinson (1969). A reduction in urinary oxalate levels by allopurinol was subsequently reported by Scott et al (1978), but only in subjects with plasma uric acids in excess of 300 pmol/l. Diet was not mentioned, so presumably was unrestricted.…”

“…One explanation for this association has been that the raised urinary uric acid levels in consequence of the purine/protein load (Loffler et al, 1980) compete for naturally occurring macromolecular inhibitors of crystal growth and thus facilitate calcium stone formation Fellstrom et al, 1982). This explanation has been invoked to explain the unexpectedly beneficial effects of the uric acid lowering drug allopurinol in reducing stone formation in some calcium oxalate stone formers (Scott et al, 1978;Tomlinson et al, 1985). An equal number of studies have refuted these claims for allopurinol (Pak et a/., 1978) and the situation remains unresolved (Fellstrom, 1985).…”

Lithogene und alithogene Harnsteinparameter vor und während der Behandlung mit Allopurinol

“…Robertson (7) konnte nachweisen, daß die inhibitorische Wirkung von sauren Mucopolysacchariden auf die Kalzium-Oxalat-Kristallisation bei niedrigen Harnsäurekonzentrationen stärker ausgeprägt ist. Verschiedene Autoren (11,13) beobachteten eine Erniedrigung der Oxalatausscheidung unter Allopurinol. Beeko (1) und Mitarbeiter berichteten über eine Steigerung der Zitratausscheidung.…”