The physician orders promethazine (Phenergan®) 25 mg IM for a patient with nausea. The promethazine bottle is labeled "50 mg per mL.". How much of this drug should be administered to the patient?

0.5 mL
1 mL
1.5 mL
2.5 mL

0.5 mL

Rationale: The patient should receive 0.5 mL of promethazine (Phenergan®), since 25 mg was ordered, but one bottle contains 50 mg per mL. Therefore, 0.5 mL would contain 25 mg of the drug.