What should be monitored due to morphine's effects?

Morphine is an opioid analgesic that is primarily used for pain management. One of its most significant effects is on the respiratory system, particularly by causing respiratory depression. This occurs because morphine acts on the brain's respiratory centers, leading to a decrease in the rate and depth of breathing.

Due to this potential for respiratory depression, it is crucial to monitor respiratory function when a patient is receiving morphine. Ensuring adequate ventilation and oxygenation is essential for patient safety, as compromised respiratory function can quickly lead to serious complications.

The other options mentioned are not directly influenced or monitored as closely when a patient is administered morphine. Increased energy levels is not typically associated with morphine use, which can lead to sedation and lethargy. Blood sugar levels and weight gain may not have a direct and immediate correlation with morphine administration, making respiratory function the primary concern in this context.