78 year old male who is on chronic opioid therapy for back pain as well as Tylenol PM one tablet at bedtime for sleep.  This gentleman had been struggling with constipation issues and had been taking Colace 100 mg daily for prevention.

This was not working well enough for him, so he started to take Milk of Mag 30 mls everyday which did help with constipation.  He continued to take this for weeks as any patient most likely would since it was beneficial for him.  With a creatinine cleareance around 25 mls/min, this patient was fortunate to have a routine check of labs which happened to include a magnesium.  Upon checking his magnesium, he was asymptomatic, but it was significantly elevated at 2.5 mEq/L with normal range of 1.2-1.9 depending upon lab.  The educational point here is that magnesium can accumulate in chronic kidney disease and education of our patients is extremely important!  The use of magnesium in chronic kidney disease can be seemingly innocent but can have substantially negative side effects when given to the wrong patient.

Need more info?  How about free info? – Please check out my 30 Medication Mistakes that all healthcare professionals should know!