title: Ephedrine- and guaifenesin-induced nephrolithiasis.
abstract: OBJECTIVE
  Ephedrine and guaifenesin are herbal supplements that have experienced increased use over the past decade. Ephedrine has been used as a stimulant and weight-loss product, guaifenesin as an expectorant and cough suppressant; both are found in combination in many antitussives and expectorants. This paper reviews the reported cases of ephedrine- and guaifenesin-induced nephrolithiasis, as well as the diagnostic techniques and treatments that have been successfully used for these stones.
  
  
  METHODS
  A systematic review of the literature pertaining to nephrolithiasis and the compounds ephedrine and guaifenesin was conducted.
  
  
  RESULTS
  Ephedrine and guaifenesin use results in over 35% of urinary stones that are related to pharmaceutical metabolites, and collectively are present in 0.1% of all urinary stones. These calculi are radiolucent, requiring the use of computerized tomography (CT scan) for diagnosis. Alkalinization therapy offers an alternative to surgical intervention and may have a role in prevention of recurrence.
  
  
  CONCLUSIONS
  Ephedrine and guaifenesin have been shown to cause nephrolithiasis in cases of abuse when taken individually or in combination. It is important for the clinician to be aware of the potential for these compounds to cause nephrolithiasis.
authors.affiliation: Department of Urologic Surgery, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN 55455, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Bennett
authors.forename: Nathan
authors.initials: N
authors.lastname: Hoffman
authors.forename: Manoj
authors.initials: M
authors.lastname: Monga
mesh_terms: D000996:Antitussive Agents / Q000009:adverse effects; D001993:Bronchodilator Agents / Q000009:adverse effects; D004809:Ephedrine / Q000009:adverse effects*; D005100:Expectorants / Q000009:adverse effects; D006140:Guaifenesin / Q000009:adverse effects*; D006801:Humans; D007668:Kidney / Q000187:drug effects*; D007669:Kidney Calculi / Q000139:chemically induced* / Q000188:drug therapy; D004366:Nonprescription Drugs / Q000009:adverse effects*
chemical_list: D000996:Antitussive Agents; D001993:Bronchodilator Agents; D005100:Expectorants; D004366:Nonprescription Drugs; D006140:Guaifenesin; D004809:Ephedrine