Has a very low therapeutic threshold. Always check a drug level if you feel compelled to use this drug. Takes 2 to 3 hours to peak effect after IV administration. Levels should be checked. Maintenance dose dependent on patient's smoking status, presence of cor pulmonale, and age.
Magnesium sulfate is shown in some studies to produce transient improvement in asthma.
Very safe but do not use in renal failure. May get flushing, transient hypotension but rare. Magnesium sulfate has been successfully used in children. Additionally, clinical judgment is important. If the patient does not look well or still feels dyspneic, consider admission to hospital.