In hospital with low magnesium, receiving magnesuim sulfate via IV, cant keep levels up, why?

My Grandmother, age 86 was hospitalized four days ago with muscle cramps, blood test showed low magnesuim, everything else within okay boundries, they have been giving her a 3 inch x 5 inch (not sure of liquid measurement) IV bag of Magnesuim sulfate. They will test her levels one hour after the IV drip is complete and her level is within normal scale... 12 hrs later, NO magnesuim will show up in her blood test. Where does all of this magnesium go to??? They have been repeating this proceedure for days now. All other health issues have been ruled out. Not Diabetic, has high blood pressure, but controlled with meds, other then that, VERY HEALTHY 86 year old. Eats logical diet, active, great weight.... had great stress test and echo test results today.. she is just making bags of magnesuim disappear.

Treatment with diuretics (water pills), some antibiotics, and some cancer medicines such as Cisplatin, can increase the loss of magnesium in urine. Poorly-controlled diabetes increases loss of magnesium in urine, causing a depletion of magnesium stores.

Gastrointestinal problems, such as malabsorption disorders, can cause magnesium depletion by preventing the body from using the magnesium in food. Chronic or excessive vomiting and diarrhea may also result in magnesium depletion. The loss of magnesium through diarrhea and fat malabsorption usually occurs after intestinal surgery or infection, but it can occur with chronic malabsorptive problems such as Crohn's disease, gluten sensitive enteropathy, and regional enteritis. Individuals with these conditions may need extra magnesium. The most common symptom of fat malabsorption, or steatorrhea, is passing greasy, offensive-smelling stools.

Many people do not get enough magnesium from their diet for reasons including the following:

* The amount of magnesium in the soil in which the food is grown may be reduced.
* Magnesium can be lost in the processing and refining of foods and in making oils from the magnesium-rich nuts and seeds. Nearly 85% of the magnesium in grains is lost during the milling of flours.
* Soaking and boiling foods can leach magnesium into the water, so the "pot liquor" from cooking vegetables may be high in magnesium and other minerals.
* Oxalic acid in vegetables such as rhubarb, spinach and chard, and phytic acid in some grains may form insoluble salts with magnesium, causing it to be eliminated rather than absorbed.
* Supplemental vitamin D or calcium reduces magnesium uptake.
* Diets high in phosphorus (meat, milk products, lentils, seeds, beans, nuts, chocolate, peanut butter, bran) reduce magnesium uptake.
* Magnesium elimination is increased in people who use alcohol, caffeine or excess sugar, or who take diuretics or birth control pills.
* Magnesium is absorbed toward the end of the small intestine. If any portion of this area (called the ileum) has been removed, magnesium absorption will be reduced.

I'm happy for you, your family and your Grandma that they discovered the reason and fixed it Report It

I am a nurse and work in a hospital Magnesium is probably swapping for another electrolyte in her blood and depleting her. Thats not so common, but it does happen.
It will all catch up and she will be fine.

When she urinates this is where her magnesuim is being lost.