Pharmacologic Profile

General Use

Management of moderate to severe pain. Fentanyl is also used as a general anesthetic adjunct.

General Action and Information

Opioids bind to opiate receptors in the CNS, where they act as agonists of endogenously occurring opioid peptides (eukephalins and endorphins). The result is alteration to the perception of and response to pain.

Contraindications

Hypersensitivity to individual agents.

Precautions

Use cautiously in patients with undiagnosed abdominal pain, head trauma or pathology, liver disease, or history of addiction to opioids. Use smaller doses initially in the elderly and those with respiratory diseases. Prolonged use may result in tolerance and the need for larger doses to relieve pain. Psychological or physical dependence may occur.

Interactions

↑the CNS depressant properties of other drugs, including alcohol, antihistamines, antidepressants, sedative/hypnotics, phenothiazines, and MAO inhibitors. Use of partial-antagonist opioid analgesics (buprenorphine, butorphanol, and nalbuphine) may precipitate opioid withdrawal in physically dependent patients. Use with MAO inhibitors or procarbazine may result in severe paradoxical reactions (especially with meperidine). Nalbuphine may ↓ the analgesic effects of other concurrently administered opioid analgesics.

Nursing Implications

Assessment

• Assess type, location, and intensity of pain prior to and at peak 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. Patients requiring higher doses of opioid agonist-antagonists should be converted to an opioid agonist.
• Opioid agonist-antagonists are not recommended for prolonged use or as first-line therapy for acute or cancer pain.
• 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. Physical stimulation may be sufficient to prevent significant hypoventilation. Dose may need to be ↓ by 25–50%. Initial drowsiness will diminish with continued use.
• Assess prior analgesic history. Antagonistic properties of agonist-antagonists may induce withdrawal symptoms (vomiting, restlessness, abdominal cramps, and ↑ BP and temperature) in patients physically dependent on opioids.
• Prolonged use may lead to physical and psychological dependence and tolerance. This should not prevent patient from receiving adequate analgesia. Most patients who receive opioid analgesics for pain do not develop psychological dependence. Progressively higher doses may be required to relieve pain with chronic therapy.
• Assess bowel function routinely. Prevention of constipation should be instituted with ↑ intake of fluids and bulk, stool softeners, and laxatives to minimize constipating effects. Stimulant laxatives should be administered routinely if opioid use exceeds 2–3 days, unless contraindicated.
• Monitor intake and output ratios. If significant discrepancies occur, assess for urinary retention and inform physician or other health care professional.
• If an opioid antagonist is required to reverse respiratory depression or coma, naloxone is the antidote. Dilute the 0.4-mg ampule of naloxone in 10 mL of 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 0.9% NaCl for a concentration of 10 mcg/mL and administer 0.5 mcg/kg every 1–2 min. Naloxone may also be administered intranasally to reverse opioid-induced respiratory depression or coma. Administer 1 spray (2 mg or 4 mg) in one nostril; may repeat dose every 2–3 min (with each subsequent dose being administered in alternate nostril). Titrate dose to avoid withdrawal, seizures, and severe pain.

Potential Nursing Diagnoses

• (auditory, visual)

Implementation

• Do not confuse morphine with hydromorphone or meperidine; errors have resulted in fatalities.
• Explain therapeutic value of medication before administration to enhance the analgesic effect.
• Regularly administered doses may be more effective than prn ("as needed") administration. Analgesic is more effective if given before pain becomes severe.
• Coadministration with nonopioid analgesics may have additive analgesic effects and may permit lower doses.
• Medication should be discontinued gradually after long-term use to prevent withdrawal symptoms.

Patient/Family Teaching

• Instruct patient on how and when to ask for pain medication.
• Advise patient that opioid analgesics have known abuse potential. Advise the patient to protect these medications from theft, and never give them to anyone other than the individual for whom it was prescribed. Store out of sight and reach of children, and in a location not accessible by others.
• Medication may cause drowsiness or dizziness. Caution patient to call for assistance when ambulating or smoking and to avoid driving or other activities requiring alertness until response to medication is known.
• Advise patient to make position changes slowly to minimize orthostatic hypotension.
• Caution patient to avoid concurrent use of alcohol or other CNS depressants with this medication.
• Encourage patient to turn, cough, and breathe deeply every 2 hr to prevent atelectasis.

Evaluation/Desired Outcomes

• Decreased severity of pain without a significant alteration in level of consciousness or respiratory status.