Magnesium sulfate
Trade names: Magnesium sulfate
Class:
Anticonvulsant, electrolyte, saline laxative
Pregnancy: (Category B)
Action:
It is an important cation present in the
extracelular fluid. 
It is an essential electrolyte for muscle
contraction, certain enzyme system & never transmissions.
Magnesium depresses CNS & control
convulsion by blocking the release of acetylcholine at the myoneural junction.
Uses:
Seizures associated with toxemia of pregnancy.
Epilepsy
laxative Hypomagnesaemia In total parenteral nutrition Dose:
Hypomagnesaemia :neonate IV
25-50mg/kg every 8-12 hours for 2-3
days, Children
IM,IV 25-50 mg/kg/dose every 4-6 hours for 3-4 days,
maintenance 30-60mg/kg/day,
Adult IM,IV 1 g every 6 hours for 4 doses
Maintenance electrolyte
requirement 25-50 mg/kg/day
Prevention of seizure recurrence in eclampsia,
initially 4 g by intravenous injection
over 5–15 minutes, , followed by intravenous infusion, 1 g/hour for at least 24
hours after last seizure
Contraindications:
• In the presence of heart block.
• In the presence of myocardial damage.
Side effects:
• Magnesium intoxication depression , flushing,
hypotension , respiratory paralysis, muscle paralysis, respiratory failure .
N.B.
• Suppression of knee-Jerk reflex can be used to determine
toxicity
• Respiratory failure may result if drug is given after
disappearance of this reflex.
Treatment of Magnesium intoxication:
• Use artificial ventilation immediately.
• Have calcium glutinate readily available for I.V. use.
Nursing
considerations:
• 
For I.V. administer. only 1.5 ml of 10%
solution\minute.
For I.V. administer. only 1.5 ml of 10%
solution\minute.
• For I.M., inject the drug deep into the muscle using 50%
solution.
• As a laxative, dissolve in a glass of ice water or other fluid
to lessen disagreeable taste.
• Obtain baseline Mg level.
• Obtain
history of kidney disease.
• Check with the physician before administering magnesium if any
of the following conditions exist:
Absent patellar or knee jerk reflex.
R.R. less than 16\m
Urinary out put less than 100 ml\4 hrs .
Patient has a history of heart block or
myocardial damage.
• Have available I.V. Calcium gluconate .
• Don’t administer drug 2 hrs preceding delivery of the baby.
If mother has received I.V. therapy of this drug 24 hours prior to
delivery, assess the newborn for neurologic & respiratory depression.
