Pharmacology Reproductive & Maternity Meds #4

Question

The nurse is caring for a pregnant client with preeclampsia who is on magnesium sulfate therapy. The nurse finds that the patient is very drowsy with a respiratory rate of 10 breaths per minute. The patient’s deep tendon reflexes are decreasing. Which medication would the nurse anticipate the physician to prescribe?

Answers

  1. Intravenous protamine sulfate
    • Rationale:

      This answer is not correct because protamine sulfate is the antidote for heparin overdose, not magnesium sulfate. Calcium gluconate is the antidote for magnesium sulfate toxicity.

  2. Intramuscular methylergometrine
    • Rationale:

      This answer is not correct because methylergometrine is an ergot alkaloid medication used to prevent hemorrhage in postpartum women, not magnesium sulfate. Calcium gluconate is the antidote for magnesium sulfate toxicity.

  3. Intravenous calcium gluconate
    • Rationale:

      This answer is correct because calcium gluconate is the antidote for magnesium sulfate toxicity. Toxicity symptoms include decreased respiratory rate, level of consciousness, and deep tendon reflexes. The nurse should monitor the patient for early toxicity symptoms so the patient will not experience extreme respiratory depression or respiratory or cardiac collapse. If symptoms begin to occur, the health care provider should be notified and the magnesium sulfate decreased or discontinued.

  4. Subcutaneous betamethasone
    • Rationale:

      This answer is not correct because betamethasone is a steroid given in-utero to help accelerate the maturity of the lungs of a preterm baby. Calcium gluconate is the antidote for magnesium sulfate toxicity.

Overview

Magnesium sulfate is given to help prevent seizures in a patient with preeclampsia. Toxicity can occur so the nurse needs to have calcium gluconate, the antidote, readily available.

Explanation

The nurse should instruct the client to hold the metered dose inhaler 1-2 inches from mouth (or two finger-breadths away) or use a spacer, and close mouth and hold breath for several seconds (10 seconds if possible). Instruction is to breathe deeply through the mouth with each inhalation, NOT short quick breaths. The client should only exhale forcefully at the beginning PRIOR to actually using the inhaler. Exhalation should be after breath is held for up to 10 seconds if possible, and should not be forceful to retain the medication.

Learning Outcomes

Magnesium sulfate is the drug of choice in preeclampsia to help prevent seizures in the pregnant patient. Although effective, magnesium sulfate can become toxic. Intravenous calcium gluconate is the antidote for magnesium sulfate toxicity. Toxicity symptoms include decreased respiratory rate, level of consciousness, and deep tendon reflexes. The nurse should monitor the patient for early toxicity symptoms so the patient will not experience extreme respiratory depression or respiratory or cardiac collapse. If symptoms begin to occur, the health care provider should be notified and the magnesium sulfate decreased or discontinued.

Test Taking Tip

Be sure to focus your nursing studies on the list antidotes for basic nursing medications. Antidotes are life-saving and are essential to know and understand.

Video Rationale