The pharmacist checking the order did not catch the error, and the bag was delivered to a skilled nursing facility. The next day, another pharmacist checking the previous day's prescriptions realized the mistake and called the facility before the bag was hung. In case one, the communication system broke down because the physician did not properly discontinue and rewrite the order. Rather than alter the dose he should have struck a line through the entire order, marked it as an error, and rewritten it completely. Just as with potassium chloride, magnesium vials should not be floor stock, even in automated dispensing machines.
Premixed solutions are a safer option than concentrated vials.
In case one, these had been offered but rejected because a single physician had insisted on D5LR as the diluent, which is not available commercially. If premixed solutions aren't used, infusions should be prepared in the pharmacy, putting another person in the loop. The fact that pharmacists did not realize overdoses in cases one and three is troubling and indicates that we cannot put blind faith in any individual's level of knowledge. This speaks to the need for magnesium sulfate administration protocols which delineate concentrations, dose limits, infusion rates, and necessary monitoring parameters. Lastly, the nurse in case one used 5 vials to prepare the 51 g infusion.