A provider order is written for prochlorperazine (Compazine®) 7.5 mg IV q 4 hrs prn N/V. Prochlorperazine (Compazine®) is available in a prefilled syringe labeled 10 mg/2 mL. How many milliliters should be given?

The milliliters of prochlorperazine (Compazine®) that must be supplied are:

Explanation:

Since the pre-filled syringe carries a label that specifies 10 mg / 2 ml, it can be deduced that the syringe contains 10 mg of the medicine in the 2 mL that is evident in the syringe, therefore, with these data and taking into account that the recommended dose in the order is 7.5 mg, a simple rule of three can be performed with the data obtained:

Then we proceed to calculate X:

1.5 milliliters is the dose that must be supplied every four hours following the indications in the order.