When administering opioid analgesics, which of the following is a key responsibility of the nurse?

Monitoring the client's respirations is a crucial responsibility when administering opioid analgesics due to the potential for respiratory depression, a serious side effect associated with these medications. Opioids can significantly depress the respiratory system, leading to reduced respiratory rate and insufficient oxygenation. By counting the client's respirations before and after administration, the nurse can assess the baseline respiratory status and monitor for any changes that occur, allowing for prompt intervention if respiratory depression is noted.

The other options do not prioritize immediate patient safety or effective monitoring of the effects of opioids. Documenting only the time of administration neglects essential details related to the client's response and medication effects. While encouraging rest is positive, it does not directly address the critical need for monitoring respiratory function. Discarding unused medication does not help in assessing or mitigating the immediate effects of opioid administration on the patient's respiratory status. Thus, continuous assessment of respiratory function is paramount for the safe management of patients receiving opioid therapy.