Obstetric Pharmacology Magnesium Sulfate n Actions Not clearly

Obstetric Pharmacology

Magnesium Sulfate n Actions • Not clearly understood • Seems to decrease release of acetylcholine at neuromuscular junction • Depresses central nervous system • Causes mild vasodilation – Decreases blood pressure – Improves placental blood flow

Magnesium Sulfate n Indications • Anticonvulsant effects in: – Pre-eclampsia – Eclampsia

Magnesium Sulfate n Contraindications • Renal disease • Cardiac failure • AV conduction defects • Myasthenia gravis

Magnesium Sulfate n Adverse effects • Muscle weakness • Respiratory depression • Hypotension • Slowed cardiac conduction/AV blocks

Magnesium Sulfate n Antidote to toxic effects • Calcium

Magnesium Sulfate n Dose • Initial: 4 to 8 gm IV over 20 minutes • Maintenance: 1 to 2 gm/hr

Pitocin n Action • Synthetic oxytocin • Stimulates uterine smooth muscle contraction

Pitocin n Indication • Control of postpartum hemorrhage

Pitocin n Contraindication • Do not administer until after baby, placenta fully delivered • May cause trapping of placenta or second twin in uterus

Pitocin n Adverse effects • Nausea, vomiting • Cardiac arrhythmias • Fluid retention with water intoxication • Transient vasodilation, reflex tachycardia

Pitocin n Dose • 10 to 40 units in 1 L of crystalloid • Infuse to: – Sustain uterine contraction – Control hemorrhage