Gynaecology & Obstetrics Which of the following is the earliest warning sign of Magnesium Sulphate toxicity? A Respiratory rate < 12 B Loss of DTRs C Altered sensorium D Urine output < 25-30 cc/hour 💡 Explanation Which of the following is the earliest warning sign of Magnesium Sulphate toxicity? ✓ Correct Answer: B. Loss of DTRs