Canterbury DHB


Magnesium Deficiency

Magnesium depletion may occur in patients receiving cyclosporin and/or tacrolimus, aminoglycosides, e.g. gentamicin/tobramycin, amphotericin B, pentamidine, diuretics, e.g. frusemide/thiazide, cisplatin and excessive IV fluids. Patients receiving these medications should have magnesium levels regularly monitored plus receive adequate magnesium supplementation to maintain normal concentrations of serum magnesium.

side effects of hypomagnesaemia include hypocalcaemia, hypokalaemia, muscle cramping, weakness, tremors, confusion, disorientation, arrythmias, seizures, cessation of bone growth with decreased osteoblast and osteoclast activity, peripheral vitamin D resistance and resistance to parathyroid hormone, augmentation of cyclosporin induced nephrotoxicity and augmentation of gentamicin induced ototoxicity.

Supplementation may be oral, or IV if severe.

Side effects of magnesium supplementation may include diarrhoea, hypotension, bradycardia, flushing, sweating, nausea, double vision and circulatory collapse. Magnesium may cause diarrhoea so begin at a lower dose and increase as tolerated. As magnesium causes diarrhoea and aluminium (contained in mylanta) causes constipation, mylanta may be more appropriate in patients prescribed magnesium only and who are experiencing diarrhoea. Magnesium oral preparations are not funded on the pharmaceutical schedule.

About this Canterbury DHB document (7811):

Document Owner:

Sean Macpherson (see Who's Who)

Last Reviewed:

January 2019

Next Review:

January 2022


Note: Only the electronic version is controlled. Once printed, this is no longer a controlled document. Disclaimer

Topic Code: 7811