Magnesium aspartate

How it works

It supplies elemental magnesium, an essential cofactor for numerous enzymatic reactions and for neuromuscular and cardiac function, correcting a deficiency state.

Prescribing in practice

• Use with caution and reduced exposure in significant renal impairment, where magnesium can accumulate and cause hypermagnesaemia.
• Diarrhoea is the most common dose-limiting side effect of oral magnesium salts.
• Oral magnesium may reduce absorption of some drugs, such as certain antibiotics, so separate the timing of administration.

Monitoring

Monitor serum magnesium, and renal function where relevant, to confirm replacement and avoid accumulation.

Counselling the patient

• Take with food to reduce stomach upset.
• Loose stools may occur; report persistent diarrhoea.
• Separate from certain other medicines by an interval as advised.

Evidence & guidelines

Oral magnesium salts are standard, well-established therapy for correcting and preventing magnesium deficiency.