Final answer:
The nurse should call the nursing supervisor or contact the on-call physician for immediate guidance on the medication dosage issue to ensure patient safety.
Step-by-step explanation:
The nurse should call the nursing supervisor when presented with a prescription that is higher than the normal dose and unable to reach the prescribing physician. It is the nursing supervisor's responsibility to assist in managing such situations and to ensure patient safety. Contacting the on-call physician is also appropriate, as this professional can provide an immediate clinical decision on whether to proceed with the medication administration.
Withholding the medication without further guidance could impact the patient's health, and administering the medication without confirmation could be dangerous. In this situation, the nurse should call the nursing supervisor. The nursing supervisor can provide guidance on how to handle the situation and may also be able to contact the on-call physician for further advice.