The co-assigned registered nurse asks the student to describe the actions and effects of this medication. Which statement, if made by the student, indicates the need for further teaching?

The co-assigned registered nurse asks the student to describe the actions and effects of this medication. Which statement, if made by the student, indicates the need for further teaching?

• A. It decreases the frequency and duration of uterine contractions.
• B. It increases acetylcholine, blocking neuromuscular transmission.
• C. It decreases the central nervous system activity, acting as an anticonvulsant.
• D. It produces flushing and sweating due to decreased peripheral blood pressure.

Answer: (B)

Magnesium sulfate acts as a central nervous system depressant with anticonvulsant properties and as a smooth muscle relaxant, including relaxing the uterus toward tocolysis. It also decreases acetylcholine release at the neuromuscular junction, which reduces neuromuscular transmission and can lead to diminished reflexes and potential respiratory depression at higher levels. It causes vasodilation, which can produce flushing and sweating. The statement describing the medication as increasing acetylcholine to block neuromuscular transmission is not correct. Magnesium does the opposite regarding acetylcholine: it lowers its release, leading to decreased NM transmission, not increased acetylcholine or a blocking effect driven by higher acetylcholine. This is why that statement signals a need for further teaching. The other described effects—uterine relaxation, CNS anticonvulsant action, and flushing from vasodilation—fit expected magnesium sulfate effects.

Magnesium sulfate acts as a central nervous system depressant with anticonvulsant properties and as a smooth muscle relaxant, including relaxing the uterus toward tocolysis. It also decreases acetylcholine release at the neuromuscular junction, which reduces neuromuscular transmission and can lead to diminished reflexes and potential respiratory depression at higher levels. It causes vasodilation, which can produce flushing and sweating.

The statement describing the medication as increasing acetylcholine to block neuromuscular transmission is not correct. Magnesium does the opposite regarding acetylcholine: it lowers its release, leading to decreased NM transmission, not increased acetylcholine or a blocking effect driven by higher acetylcholine. This is why that statement signals a need for further teaching. The other described effects—uterine relaxation, CNS anticonvulsant action, and flushing from vasodilation—fit expected magnesium sulfate effects.