Table 9.

Signs and symptoms of magnesium toxicity and clinical management.

Laxative effect, diarrhea

Fall in blood pressure with dizziness to severe hypotension

Muscle weakness (and depressed deep tendon reflexes)

Severe back pain and pelvic pain

Confusion and loss of consciousness

Difficulty breathing to respiratory arrest

Cardiac arrhythmias to cardiac arrest

Other effects: lethargy, confusion, deterioration of kidney function

Treatment:

Mild magnesium overdose:

(i) Discontinue over the counter magnesium-containing laxatives, antacids, or magnesium supplements and rule out renal impairment

Severe magnesium overdose (>1.1 mmol/l)

(i) Artificial respiratory support may be needed

(ii) Intravenous fluids (saline diuresis) and furosemide

(iii) IV calcium gluconate or calcium chloride (10% solution 500–1000 mg IV)

(iv) Renal dialysis