How many full vials of a drug needed to make sure there is enough drug for the first four hours?

Question

I know that the drug is available as 1 mg/mL in 5 mL vials.

I know the drug is delivered at a rate of 3.6 mg/kg/hr.

Am I supposed to multiply 3.6 * 4= 14.4 because it’s asking about 4 hours?

If if so I don’t know how to set up the proportion so figure it how many vials will be used.

Answer 1

To figure out how many vials are needed for the first 4 hours, first find out how many mg are needed for that time period.

3.6 mg/kg/hr x 4 hr = 14.4 mg/kg. This is what you've already done, except you should include the proper units. It isn't 14.4 mg. It is 14.4 mg/kg.

1. To set up the rest of the problem, you need to know the patient's weight in kg. Multiply the weight by 14.4 mg/kg to get total mg needed.
2. Each vial contains 5 mg (1 mg/ml x 5 ml = 5 mg). Divide the total mg needed just calculated by 5 mg/vial to obtain number of vials needed. Round off to the higher value so you don't run out. For example, if you find that 3.2 vials are needed, the correct answer will be 4 full vials.