Pain management in critical care requires a systematic pharmacological approach aimed at relieving pain, reducing physiological stress, promoting comfort, and facilitating diagnostic and therapeutic procedures. The choice of analgesic depends on the intensity and type of pain, the patient’s clinical condition, organ function, level of consciousness, and potential adverse effects. In critically ill patients, analgesics should be administered according to regular assessment and individualized treatment goals. Opioids are the principal pharmacological agents used for moderate to severe acute pain in critically ill patients. Commonly used opioids include morphine, fentanyl, hydromorphone, and remifentanil. Morphine is effective for severe pain but may cause respiratory depression, hypotension, nausea, vomiting, constipation, and accumulation of active metabolites in renal impairment. Fentanyl has a rapid onset and is commonly administered intravenously because of its relatively stable cardiovascular effects. Remifentanil has an extremely short duration of action and can be useful when rapid adjustment of analgesia is required. Nurses must closely monitor respiratory rate, oxygen saturation, blood pressure, level of consciousness, and signs of excessive sedation. Naloxone may be used to reverse significant opioid-induced respiratory depression when