Calcium nephrolithiasis (CaNL) accounts for more than 70% of all renal stones, and its prevalence has increased in the last decades. Under this definition are included patients passing stones, composed of calcium oxalates and/or calcium phosphates. Current views of the pathogenesis of CaNL are based on the role of metabolic abnormalities which concur to render urines more conducive to crystallization. Therefore, the diagnostic approach is aimed at detecting these abnormalities, and the medical treatment assumes that a decrease in the risk of lithogenesis will result in remission or improvement of recurrences. The workup of the patients with CaNL begins with the analysis of passed stones and X-ray, sonography or other imaging techniques. Eligible patients, that is, both recurrent active stone formers and single-stone formers with individual risk factors, are considered for a metabolic evaluation, by which a number of blood and urine parameters are measured and others calculated. These include estimates of urine state of saturation with calcium and uric acid salts, net gastrointestinal alkali absorption, renal threshold of phosphate and other renal clearances and net acid and total nitrogen excretions. Basically, this screening is informative on renal function, metabolic abnormalities and their pathophysiology, risk of stone formation and dietary habits. During treatment it gives information about patient compliance and adverse effects of therapy. The cost of a comprehensive screening in Piedmont is 192,000 ITL (100 Euro) and rises to 300,000 ITL (154 Euro) if hormones and hydroxyproline are measured. In individual patients second- and third-level studies are performed, in order to detect systemic diseases which account for about 20% of CaNL in our series. Cost-to-benefit analysis has shown that the medical procedures for CaNL yield considerable saving in terms of difference between expenditure for drugs and testing and reduction of stone events. However, the current workup cannot be considered exhaustive, because misleading events may hamper the relation between laboratory findings and clinical outcome, and factors other than urine composition have appeared on the scenario of nephrolithiasis. These represent our challenge for the third millennium.

Gault MH, Parfrey PS, Robertson WG: Idiopathic calcium phosphate nephrolithiasis. Nephron 1988;48:265–273.
Smith LH : The medical aspects of urolithiasis : An overview. J Urol 1989;141:707–710.
Coe FL, Keck J, Norton E : The natural history of untreated calcium nephrolithiasis. JAMA 1977;238 :1519–1523.
Parks JH, Coe FL: The financial effects of kidney stone prevention. Kidney Int 1996;50:1706–1712.
Marangella M, Bruno M, Cossedu D, Manganaro M, Tricerri A, Vitale C, Linari F: Prevalence of chronic renal insufficiency in the course of idiopathic recurrent calcium stone disease: Risk factors and patterns of progression. Nephron 1990;54:302–306.
Marangella M: Metabolic evaluation of calcium nephrolithiasis. J Nephrol 1995;8:179–184.
Parks JH, Coward M, Coe FL: Correspondence between stone composition and urine supersaturation in nephrolithiasis. Kidney Int 1997;51:894–900.
Hosking DH, Erickson SB, van den Berg CJ, Wilson D, Smith LH: The stone clinic effect in patients with idiopathic calcium urolithiasis. J Urol 1983;130:1115–1119.
Drach GW, Perin R, Jacobs S: Outpatient evaluation of patients with calcium urolithiasis. J Urol 1979;121:564–567.
Pak CYC, Britton F, Peterson R, Ward D, Northcutt C, Breslau NA, McGuire J, Sakhaee K, Bush S, Nicar M, Norman D, Peters P: Ambulatory evaluation of nephrolithiasis: Classification, clinical presentation and diagnostic criteria. Am J Med 1980;69:19–30.
Preminger GM: The metabolic evaluation of patients with recurrent nephrolithiasis: A review of comprehensive and simplified approaches. J Urol 1989;141:760–763.
Parks JH, Coe FL: A urinary calcium-citrate index for the evaluation of nephrolithiasis. Kidney Int 1986;30:85–90.
Hess B, Hasler-Strub U, Ackermann D, Jaeger P: Metabolic evaluation of patients with recurrent calcium nephrolithiasis. Nephrol Dial Transplant 1997;12:1362–1368.
Marangella M, Daniele PG, Ronzani M, Sonego S, Linari F: Urine saturation with calcium salts in normal subjects and idiopathic calcium stone formers estimated by an improved computer model system. Urol Res 1985;3:189–193.
Oh MS: A new method for estimating GI absorption of alkali. Kidney Int 1989;36:915–917.
Lemann J Jr, Gray RW: Idiopathic hypercalciuria. J Urol 1989;141:715–719.
Pak CYC, Ohata M, Lawrence EC, Snyder W. The hypercalciurias: Causes, parathyroid functions and diagnostic criteria. J Clin Invest 1974;54:387–400.
Hess B, Michel R, Takkinen R, Ackermann D, Jaeger P: Risk factors for low urinary citrate in calcium nephrolithiasis: Low vegetable fibre intake and low urine volume to be added to the list. Nephrol Dial Tranplant 1994; 9:642–649.
Marangella M, Petrarulo M, Vitale C, Cosseddu D, Linari F: Plasma and urine glycolate assays for differentiating the hyperoxaluria syndromes. J Urol 1992;148:986–990.
Pietschmann F, Breslau NA, Pak CYC: Reduced vertebral bone density in hypercalciuric nephrolithiasis. J Bone Miner Res 1992;7:1383–1388.
Messa P, Marangella M, Paganin L, Codardini M, Cruciatti A, Turrin D, Filiberto Z, Mioni G: Different dietary calcium intake and relative supersaturation of calcium oxalate in the urine of patients forming renal stones. Clin Sci 1997;93:257–263.
Lemann J Jr: Urinary calcium excretion and net acid excretion: Effects of dietary proteins, carbohydrate and calories; in Schwille PO, Smith LH, Robertson WG, Vahlensieck W (eds): Urolithiasis and Related Clinical Research. New York, Plenum Press, 1985, pp 53–61.
Marangella M, Bianco O, Martini C, Petrarulo M, Vitale C, Linari F: Effect of animal and vegetal protein intake on oxalate excretion in idiopathic calcium stone disease. Br J Urol 1989;63:348–351.
Breslau NA, Brinkley L, Hill KD, Pak CYC: Relationship of animal protein-rich diet to kidney stone formation and calcium metabolism. J Clin Endocrinol Metab 1988;66:140–146.
Sakhaee K, Williams RH, Oh MS, Padalino P, Adams Huet B, Whitson P, Pak CYC: Alkali absorption and citrate excretion in calcium nephrolithiasis. J Bone Miner Res 1993;8:789–794.
Marangella M: Diagnostic profiles of the metabolic abnormalities in idiopathic calcium nephrolithiasis. Ital J Miner Electrolyte Metab 1994;8:103–109.
Marangella M, Vitale C, Petrarulo M, Rovera L, Dutto F: Effects of mineral composition of drinking water on risk for stone formation and bone metabolism in idiopathic calcium nephrolithiasis. Clin Sci 1996;91:313–318.
Ettinger B, Tang A, Citron JT, Livermore B, Williams T: Randomized trial of allopurinol in the prevention of calcium oxalate calculi. N Engl J Med 1986;315:1386–1389.
Ettinger B, Citron JT, Livermore B, Dolman LI: Chlorthalidone reduces calcium oxalate calculus recurrence but magnesium hydroxide does not. J Urol 1989;139:679–684.
Barcelo P, Wuhl O, Servitge E, Rousaud A, Pak CYC: Randomized double-blind study of potassium citrate in idiopathic hypocitraturic calcium nephrolithiasis. J Urol 1993;150:1761–1764.
Borghi L, Meschi T, Amato F, Briganti A, Novarini A: Urinary volume, water and recurrences in idiopathic calcium nephrolithiasis. J Urol 1996;155:839–843.
Coe FL, Nakagawa Y, Parks JH: Inhibitors within the nephron. Am J Kidney Dis 1991;17:407–413.
Mandel N, Riese R: Crystal-cell interactions: Crystal binding to rat renal papillary tip collecting duct cells in culture. Am J Kidney Dis 1991;17:402–406.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.