• Assess type, location, and intensity of pain prior to and 90–120 min following administration. When titrating opioid doses, ↑ of 25–50% should be administered until there is either a 50% ↓ in the patient’s pain rating on a numerical or visual analogue scale or the patient reports satisfactory pain relief. A repeat dose can be safely administered at the time of the peak if previous dose is ineffective and side effects are minimal.
• An equianalgesic chart (see Equianalgesic Dosing Guidelines) should be used when changing routes or when changing from one opioid to another.
• Assess BP, pulse, and respirations before and periodically during administration. If respiratory rate is <10/min, assess level of sedation. Dose may need to be ↓ by 25–50%. Initial drowsiness will diminish with continued use. Monitor for respiratory depression, especially during initiation or following dose ↑; serious, life-threatening, or fatal respiratory depression may occur. May cause sleep-related breathing disorders (central sleep apnea, sleep-related hypoxemia).
• Assess bowel function routinely. Prevention of constipation should be instituted with increased intake of fluids and bulk and with laxatives to minimize constipating effects. Stimulant laxatives should be administered routinely if opioid use exceeds 2–3 days, unless contraindicated. Consider drugs for opioid induced constipation.
• Assess for opioid-induced hyperalgesia, which can appear as ↑ levels of pain on increasing the dose of the opioid, ↓ levels of pain on decreasing the dose of the opioid, or pain from ordinarily nonpainful stimuli (allodynia). This condition is different from tolerance. If a patient is suspected to be experiencing opioid-induced hyperalgesia, consider ↓ the dose of the current opioid or switching to a different opioid analgesic.
• Prolonged use may lead to physical and psychological dependence and tolerance. This should not prevent patient from receiving adequate analgesia. Most patients who receive levorphanol for pain do not develop psychological dependence. Progressively higher doses may be required to relieve pain with long-term therapy.
• Assess risk for opioid addiction, abuse, or misuse prior to administration.

Lab Test Considerations:

• May ↑ plasma amylase and lipase concentrations.

Toxicity and Overdose:

• If an opioid antagonist is required to reverse respiratory depression or coma, naloxone is the antidote to improve respiratory function without reversing analgesia. Dilute the 0.4-mg ampule of naloxone in 10 mL of sterile water or 0.9% NaCl and administer 0.5 mL (0.02 mg) by IV push every 2 min. For children and patients weighing <40 kg, dilute 0.1 mg of naloxone in 10 mL of sterile water or 0.9% NaCl for a concentration of 10 mcg/mL and administer 0.5 mcg/kg every 1–2 min. Titrate to avoid withdrawal, seizures, and severe pain.