From the Guidelines
Yes, it is possible to be allergic to morphine but not to Dilaudid (hydromorphone). These medications are both opioids but have different chemical structures. Morphine allergies typically involve a histamine release reaction, causing symptoms like itching, hives, swelling, or in severe cases, breathing difficulties. According to a study published in Critical Care in 2013 1, hydromorphone causes little or no histamine release, and may be safely administered to patients who report a type 2 allergy to morphine (urticaria, pruritis, and facial flushing). Some key points to consider include:
- Hydromorphone is more potent than morphine, with a smaller milligram dose required for effective pain management
- The difference in histamine release between morphine and hydromorphone makes hydromorphone a safer option for patients with morphine allergies
- True allergies to opioids are relatively rare, and what many people experience are side effects rather than allergic reactions
- If you suspect you have a morphine allergy, it's crucial to inform all healthcare providers and wear a medical alert bracelet
- A healthcare provider should supervise any transition between opioid medications to monitor for potential cross-reactivity, as some patients may still react to multiple opioids despite their structural differences.
From the Research
Opioid Allergy and Cross-Reactivity
- It is possible to be allergic to one opioid and not another, as allergic reactions to opioids are specific to the individual drug [(2,3)].
- True allergic reactions to opioids are rare, and most adverse reactions can be attributed to side effects or pseudo-allergies [(2,3)].
- A study found no cross-reactivity among three opioid classes (natural, semisynthetic, and synthetic opioids), resulting in 100% re-exposure tolerance rates 3.
Morphine and Dilaudid Allergy
- Morphine is a naturally occurring opioid compound that can cause allergic reactions 2.
- There is no direct evidence to suggest that an allergy to morphine would automatically mean an allergy to Dilaudid (hydromorphone), as they are different opioid compounds 3.
- However, it is essential to note that individual reactions to opioids can vary, and a detailed allergy history is crucial when deciding to administer any opioid [(2,3)].