2013 Volume 2 Issue 1 Pages 3-9
Most of chronic kidney disease (CKD) patients are elder adults. Elderly patients are usually having gastrointestinal motility disorder, especially, chronic constipation. Magnesium oxide (MgO) is used for main treatment of the constipation as a laxative without habit-forming and is often prescribed for a long term in Japan. When MgO is administrated to renal function decline patients, the caution about hypermagnesemia is raised in not only Japan, but also Europe and USA.The warning about “hypermagnesemia” in the long-term dosage of MgO is issued safety information by pharmaceuticals and medical devices agency in November, 2008. We have very few evidence about the dose of the MgO for the renal function decline patients. Therefore, we examined correlation between renal function decline and the risk of hypermagnesemia, influence of doses of MgO and serum Mg levels.The serum Mg levels and the serum creatinine (Cr) levels are extracted from laboratory data of the patients receiving MgO during the period of from April 1, 2010 to February 29, 2012. In extracted laboratory data, there were 87 cases with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m2 classified more than CKD stage 3 in CKD medical treatment guide 2009. These laboratory data of 87 cases were performed statistical analysis.These results indicate a significant correlation between eGFR and serum Mg levels. In the patients of 45 ≦ eGFR<60, a significant correlation was not revealed between MgO dose and a serum Mg level. On the other hand, in the patients with eGFR<45, MgO dose correlated with a serum Mg level significantly. In the patients with eGFR<15, a mean serum Mg level was over the normal upper limit.The part of patients with CKD stage 5 (eGFR<15) receiving MgO dose of >1000mg/day was elevated serum Mg concentration over 6 mg/dL. It was thought that attention to hypermagnesaemia was necessary for more than 1000mg/day dose in patients with eGFR<15. It was suggested that MgO laxative is administrated more safely in the patients with eGFR ≧ 45 than that with eGFR < 45 in this study. Furthermore, it is suggested that the patients with eGFR<45 are received MgO laxative safely by measuring the serum Mg level, and setting a dose depending on renal function decline.
