title: Magnesium lactate in the treatment of Gitelman syndrome: patient-reported outcomes.
abstract: Gitelman syndrome (GS) is a rare recessively inherited renal tubulopathy associated with renal potassium (K) and magnesium (Mg) loss. It requires lifelong K and Mg supplementation at high doses that are at best unpalatable and at worst, intolerable. In particular, gastrointestinal side effects often limit full therapeutic usage.
  
  
  
  We report here the analysis of a cohort of 28 adult patients with genetically proven GS who attend our specialist tubular disorders clinic, in whom we initiated the use of a modified-release Mg preparation (slow-release Mg lactate) and who were surveyed by questionnaire.
  
  
  
  Twenty-five patients (89%) preferred the new treatment regimen. Of these 25, 17 (68%) regarded their symptom burden as improved and seven reported no worsening. Of the 25 who were not Mg-treatment naïve, 13 (59%) patients reported fewer side effects, 7 (32%) described them as the same and only 2 (9%) considered side effects to be worse. Five were able to increase their dose without ill-effect. Overall, biochemistry improved in 91% of the 23 patients switched from therapy with other preparations who chose to continue the modified-release Mg preparation. Eleven (48%) improved both their Mg and K mean levels, 3 (13%) improved Mg levels only and in 7 cases (30%), K levels alone rose.
  
  
  
  Patient-reported and biochemical outcomes using modified-release Mg supplements were very favourable, and patient choice should play a large part in choosing Mg supplements with GS patients.
authors.affiliation: Department of Medical Genetics, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Robinson
authors.affiliation: Division of Renal Medicine and Division of Experimental Medicine, University of Cambridge, Cambridge, UK.|Department of Medical Genetics, Cambridge Institute for Medical Research, Addenbrookes Hospital, Hills Road, Cambridge, UK.
authors.forename: Fiona E
authors.initials: FE
authors.lastname: Karet Frankl
mesh_terms: D000328:Adult; D000368:Aged; D003692:Delayed-Action Preparations; D019587:Dietary Supplements; D005260:Female; D053579:Gitelman Syndrome / Q000188:drug therapy*; D006801:Humans; D008274:Magnesium / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D000071066:Patient Reported Outcome Measures; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003692:Delayed-Action Preparations; D008274:Magnesium
keywords: Gitelman syndrome; hypomagnesaemia; patient-reported outcomes; tubulopathy