What is a major risk associated with an overdose of magnesium sulfate?

A major risk associated with an overdose of magnesium sulfate is cardiac arrest. Magnesium sulfate is commonly used in obstetric care, particularly for its neuroprotective effects in preterm labor and management of eclampsia. While it serves many beneficial purposes, an overdose can lead to critically high levels of magnesium in the blood, causing various physiological disturbances.

When magnesium levels become excessively high, one of the most serious risks is the impact on the cardiovascular system. Elevated magnesium can lead to pronounced muscle relaxation, including relaxation of the cardiac muscle and blood vessels. This can disrupt normal heart rhythm and potentially lead to life-threatening arrhythmias and cardiac arrest.

In addition to cardiac concerns, high levels of magnesium can also affect respiratory function and cause respiratory failure. However, the most life-threatening manifestation of an overdose is the risk of cardiac arrest. Therefore, vigilance in monitoring magnesium levels during treatment is essential to prevent such severe complications.

Other risks of magnesium sulfate overdose, like severe hypotension and renal failure, can occur, but cardiac arrest remains one of the most acute and dangerous consequences. This understanding highlights the importance of careful dosing and monitoring when using magnesium sulfate in clinical practice.