Magnesium sulfate is a tocolytic agent used to prevent preterm labor by suppressing uterine contractions, especially for patients contraindicated to beta-adrenergic agents. It serves multiple roles, including seizure and fetal neuroprotection, with specific dosing guidelines and side effects. Common adverse reactions include maternal flushing and respiratory depression in neonates, requiring careful monitoring by nursing staff.

1. INTRODUCTION
TOCOLYTIC AGENT:
• Drugs that prevent preterm labor and immature birth by
suppressing uterine contractions (TOCOLYSIS). Agents used to
delay premature uterine activity include magnesium sulfate, beta-
mimetics, oxytocin antagonists, calcium channel inhibitors, and
adrenergic beta-receptor agonists. serum magnesium levels of 4–7
mEq/L are considered therapeutic for inhibiting myometrial
activity.

2. MAGNESIUM SULPHATE
• Magnesium sulphate (MgSO4) has been
successfully used to inhibit premature labor.
• Magnesium sulphate is used mainly for patients
who have contraindications to beta- adrenergic
agents.
• Magnesium sulfate used as a second-line tocolysis.
Generic Name : Magnesium sulfate
Local Name : Epsom salt
Chemical Formula : MgSO4
Brand Name: Epsal, Epsom Salt, Rite Aid First Aid
Epsom Salt, slave.

3. USE IN OBSTETRICS
• Seizer protection
• Fetal neuroprotection
• Tocolytics
• DOSE AND ROUTE
• Initial Loading dose 4-6gm IV (10-20% solution) over 20-30 mins.
Maintainance followed by an infusion of 1-2gm/hr to continue tocolysis
for 12 hrs after the contractions have stopped.

4. HALF LIFE
43.2 Hours (New Burns)
PHARMACODYNAMICS
• Magnesium sulfate is a small colorless crystal used as an
Anticonvulsant. It causes direct inhibition of action potentials in
myometrial muscles cells.
• Which decreases the frequency and force of contractions.
PHARMACOGENOMIC EFFECT
• Not available

5. MECHANISM OF ACTION
• Cerebral vasodilatation thus reducing ischemia due to vasospasm.
• Reduction in inflammatory cytokines and/or oxygen free radicals.
• It inhibits platelet activation.
• Peripheral vasodilatation, thus decreases systemic vascular resistance.
• Dilates the orbital vessels, increases cardiac output, renal blood flow
and uteroplacental blood flow.

6. INDICATION
• Used for immediate control of life-threatening convulsions in the
treatment of severe toxemias (pre-eclampsia and eclampsia) of
pregnancy and in the treatment of acute nephritis in children.
• Also indicated for replacement therapy in magnesium deficiency,
especially in acute hypomagnesemia accompanied by signs of tetany
similar to those of hypocalcemia.
• Also used in uterine tetany as a myometrial relaxant.

7. CONTRAINDICATIONS
• Impaired renal function.
• Heart block, myocardial damage.
• Myasthenia gravis.
• Drug interaction: Nifedipine, anesthetic drugs.

8. SIDE EFFECTS & PRECAUTIONS:
• Common maternal side effects are flushing, perspiration, headache,
muscle weakness, rarely pulmonary oedema.
• Neonatal side effects are lethargy, hypotonia, rarely respiratory
depression.
• Adverse reactions include hypotension, ECG changes, diarrhea, urinary
retention, CNS depression and respiratory depression.

9. Toxicity
•Areflaxia
•Depression
•Respiratory arrest
•Oliguria
•Chest pain
•Slurred speech
•Hypothermia
•Confusion

10. NURSING RESPONSIBILITY
• Use caution with renal insufficiency.
• May cause decreased respiratory rate, arrythmias, hypotension, muscle weakness.
• Monitor EKG and respiratory status.
• Monitor Mg levels.
• Ensure dosage with secondary practitioner.
• Calcium gluconate is the antidote.
• Document magnesium sulfate infusion in grams per hour
• Continuous fetal assessment
• Continuous pulse oximetry
• Assess maternal and fetal status prior to initiation of magnesium. Maternal vital signs,
oxygen saturation, level of consciousness, characteristics of fetal heart rate and uterine
activity.
• Ensure anesthesia is aware of infusion.

11. • Checked urine output.
• Checked patella reflexes.
• B.P monitoring.

12. Thank You