title: Calcium metabolism in acidotic patients induced by carbonic anhydrase inhibitors: responses to citrate.
abstract: Calcium metabolism and its response to citrate were examined in 51 patients with glaucoma receiving carbonic anhydrase inhibitors (acetazolamide or methazolamide). Metabolic acidosis, hypocitraturia and increased incidence of nephrolithiasis were induced by both drugs. However, the acidosis was milder with methazolamide administration. Normocalciuria was observed in 29 patients and was shown to be a result of low filtered calcium. Renal hypercalciuria in 16 patients was associated with elevated parathyroid hormone but nephrogenic cyclic adenosine monophosphate remained within normal limits. Citrate in the form of potassium citrate (4.3 mmol.) and sodium citrate (4.0 mmol.) did not correct the metabolic acidosis or hypocitraturia but consistently decreased fasting and 24-hour urinary calcium excretion in patients with renal hypercalciuria. This event did not occur in patients with normocalciuria or absorptive hypercalciuria. These results suggest that a small amount of citrate could reverse renal hypercalciuria without correcting the metabolic acidosis.
authors.affiliation: Department of Urology, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Higashihara
authors.forename: K
authors.initials: K
authors.lastname: Nutahara
authors.forename: T
authors.initials: T
authors.lastname: Takeuchi
authors.forename: N
authors.initials: N
authors.lastname: Shoji
authors.forename: M
authors.initials: M
authors.lastname: Araie
authors.forename: Y
authors.initials: Y
authors.lastname: Aso
mesh_terms: D000086:Acetazolamide / Q000009:adverse effects / Q000627:therapeutic use; D000138:Acidosis / Q000139:chemically induced* / Q000188:drug therapy; D002118:Calcium / Q000378:metabolism*; D002257:Carbonic Anhydrase Inhibitors / Q000009:adverse effects*; D002951:Citrates / Q000627:therapeutic use*; D019343:Citric Acid; D005260:Female; D005901:Glaucoma / Q000188:drug therapy; D006801:Humans; D007669:Kidney Calculi / Q000139:chemically induced* / Q000453:epidemiology; D008297:Male; D008704:Methazolamide / Q000009:adverse effects / Q000627:therapeutic use; D008875:Middle Aged; D012307:Risk Factors
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D002951:Citrates; D019343:Citric Acid; D000086:Acetazolamide; D002118:Calcium; D008704:Methazolamide