Appropriate Action Before Administering Injectable Medication

A nurse is preparing to administer a prescribed dose of an injectable medication to a patient in a hospital setting. The order states to administer 1 mg of the medication intramuscularly (IM) every 6 hours as needed for severe pain. Upon inspection, the nurse notes that the medication is available in a 2 mg/mL concentration. The patient has been experiencing intermittent pain and has not received any doses of the medication yet. What is the most appropriate action for the nurse to take before administering the medication?