Name two signs of magnesium sulfate toxicity to monitor for in the mother.

• A. Diminished deep tendon reflexes and respiratory depression
• B. Hypertension and tachycardia
• C. Increased urine output
• D. Fever and chills

Answer: (A)

Magnesium sulfate toxicity manifests when the drug’s depressant effects on neuromuscular transmission and the respiratory system become evident. The two key signs to monitor are diminished deep tendon reflexes and respiratory depression. Diminished reflexes reflect early neuromuscular blockade from elevated magnesium levels, while changes in breathing indicate that the respiratory muscles are being affected and the patient may be at risk for respiratory failure. Monitoring these two findings provides reliable, bedside indicators of rising magnesium levels and helps guide timely actions, such as adjusting or stopping the infusion and notifying the clinician. If severe toxicity is suspected, calcium gluconate is the antidote typically used, so be prepared to initiate that per protocol.