MAGNESIUM LACTATE IN THE TREATMENT OF GITELMAN SYNDROME –PATIENT REPORTED OUTCOMES
INTRODUCTION:Gitelman syndrome (GS) is a rare recessively inherited renal tubulopathy associated with renal potassium (K) and magnesium (Mg) loss. It requires lifelong potassium and magnesium supplementation at high doses that are at best unpalatable and at worst, intolerable. In particular, gastrointestinal side effects often limit full therapeutic usage. In an effort to improve tolerability, efficacy and quality of life for those with the condition we invited a group to trial the use of slow release Magnesium Lactate(SRMgL) in place of their normal Mg therapy and report their experiences.
METHODS: 28 adult patients with genetically proven GSfrom our specialist renalclinic were surveyed using a purpose-designed questionnaire together with analysis of serum biochemistry following their commencement of SRMgL.
RESULTS:SRMgL was well tolerated by the majority – 25/28 (89%) chose to continue it. Of these, 17 (68%) regarded their symptom burden as improved and seven (28%) reported no worsening compare to their pre SRMgL experience. Of the 22/25 in the overall group who had transferred from another Mg preparation and continued onSRMgL, 13 (59%) patients reported fewer side effects on SRMgL, 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 new preparation. 11 (48%) improved both their Mg and K mean levels, 3 (13%) improved Mg levels only and in 7 cases (30%) K levels alone rose. Notably, 20 patients reached therapeutic target K levels when on SRMgL compared to 13 prior to its use (p=0.024).
CONCLUSIONS: Patient-reported and biochemical outcomes using SRMgL were very favourable. In terms of patient experience, SRMgL is useful for treating hypomagnesemia and is particularly appropriate for those with GS where large doses of Mg may be required to maintain adequate serum Mg levels and tolerability of an inevitably unpalatable medicine is paramount. Patient preference should play a large part in choosing magnesium supplements with Gitelman syndrome patients.