What opioid should be used for a patient with a severe headache and a codeine allergy?

Opioid Selection for Severe Headache in Patients with Codeine Allergy

For patients with severe headache and codeine allergy, hydromorphone is recommended as the preferred opioid due to its quicker onset of action, comparable cost to morphine, and potentially superior analgesic profile. 1

First-Line Opioid Options

• Hydromorphone (0.015 mg/kg IV) is recommended as a comparable, potentially superior analgesic to morphine for acute severe pain, with a quicker onset of action and lower risk of dose stacking 1
• Fentanyl (1 mcg/kg, then ~30 mcg q 5 min) is recommended over morphine for acute moderate-severe pain, particularly important for patients with allergies as people with morphine allergies typically do not have allergies to fentanyl 1
• Oxycodone is another viable option, as it appears to have equal pain relief and side effect profiles compared to hydromorphone when dosed in an equal analgesic way 1

Dosing Considerations

• For opioid-naïve patients, start with the lowest possible dose to achieve acceptable analgesia 1
• Initiate opioids as immediate release and PRN (as needed) to establish an effective dose, with early assessment and frequent titration 1
• For IV administration of hydromorphone, the recommended starting dose is 0.015 mg/kg 1
• For oral administration, morphine equivalent of 5-15 mg is recommended for opioid-naïve patients 1

Clinical Advantages of Hydromorphone

• Hydromorphone has a quicker onset of action compared to morphine 1
• Because hydromorphone is more potent at a much smaller milligram dose, physicians may be more likely to adequately treat pain (1.5 mg hydromorphone vs. 10 mg morphine) 1
• Morphine has a longer onset of action and greater risk for dose stacking, which places patients at higher risk for toxicity (especially in renal failure) and hypoventilation 1

Important Considerations and Cautions

• Patients with codeine allergy may have cross-reactivity with other opioids, though fentanyl is generally considered safe for patients with morphine allergies 1
• For headache specifically, opioids should be used judiciously as they may contribute to medication-overuse headache with frequent use 1, 2
• Limit acute therapy to no more than twice per week to guard against medication-overuse headache 1
• Consider non-opioid options first for milder headaches, such as NSAIDs or triptans, if not contraindicated 1, 3
• For patients with substance use disorders, collaborate with pain specialists to determine optimal approach 1

Patient Monitoring

• Routine follow-up should be performed during each outpatient contact or at least daily for inpatients 1
• Monitor for use of analgesics as prescribed, especially in patients with risk factors for or history of abuse 1
• Provide patients with a written follow-up pain plan, including prescribed medications 1

By following these recommendations, clinicians can effectively manage severe headache pain in patients with codeine allergy while minimizing risks and adverse effects.