Fast Five Quiz: Kidney Stones (Renal Calculi)

Vecihi Batuman, MD


May 12, 2021

Low fluid intake (often in association with biochemical abnormalities in urine composition) with subsequent low volume of urine production can lead to high concentrations of stone-forming solutes in the urine. This is an important, if not the most important, environmental factor in kidney stone formation. The exact nature of the tubular damage or dysfunction that leads to stone formation has not been characterized.

The four main chemical types of renal calculi, which together are associated with more than 20 underlying etiologies, are:

  • Calcium stones

  • Struvite (magnesium ammonium phosphate) stones

  • Uric acid stones

  • Cystine stones

Numerous medications or their metabolites can precipitate in urine, causing stone formation. These include the following:

  • Indinavir

  • Atazanavir

  • Guaifenesin

  • Triamterene

  • Topiramate

  • Silicate (overuse of antacids containing magnesium silicate)

  • Sulfa drugs, including sulfasalazine, sulfadiazine, acetylsulfamethoxazole, acetylsulfisoxazole, and acetylsulfaguanidine

  • Ceftriaxone (rarely)

Read more about the etiology of renal calculi.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.