The physician has ordered 6 mg of morphine sulfate every 3 to 4 hours

The physician has ordered 6 mg of morphine sulfate every 3 to 4 hours prn for a client’s postop-erative pain. The unit dose in the medication dispenser has 15 mg in 1 mL. How much solution should the nurse give?

1. 1/5 mL
2. 1/3 mL
3. 2/5 mL
4. 1/4 mL

ANSWER

ANS: 3
The nurse should use the following formula to calculate a drug dosage:

6 mg
15 mg x 1 mL = 2/5 mL

Options 1, 2, and 4 are not correct dosage calculations.