Final answer:
The PN can proceed to give digoxin to the infant since the heart rate of 120 beats per minute is within the normal range for a 2-month old. Continuous monitoring is essential due to the sensitivity of infants to digoxin.
Step-by-step explanation:
The PN should administer the digoxin as the infant's heart rate of 120 beats per minute falls within the normal range for their age, which is typically between 80 to 160 beats per minute. It is crucial to monitor infant's heart rate before and after administration of digoxin to avoid potential complications such as digoxin toxicity, especially as infants and young children are more sensitive to the effects of this medication. However, it is always important to adhere to hospital protocols and the prescribing physician's guidelines when administering any medication to an infant.