From the Guidelines
A patient with a morphine allergy may be able to take hydrocodone, but caution is warranted due to the possibility of cross-reactivity between the two opioid medications. True allergies to morphine are relatively rare, and many reactions labeled as "allergies" are actually side effects like nausea or itching 1. If the patient has experienced a true allergic reaction to morphine (such as hives, difficulty breathing, or anaphylaxis), there is a possibility of cross-reactivity with hydrocodone since both are opioid medications. However, hydrocodone has a different chemical structure than morphine and may be tolerated even in patients with morphine allergies.
Before taking hydrocodone, the patient should discuss their specific morphine reaction with their healthcare provider who can determine if hydrocodone is safe for them. The healthcare provider should consider the severity and nature of the original morphine reaction to guide the decision-making process regarding hydrocodone use 1. If prescribed hydrocodone, the patient should start with a low dose, such as 5-15 mg PO Q4-6h PRN, and be monitored for any adverse reactions 1.
Some key considerations for the use of hydrocodone in patients with morphine allergies include:
- The potential for cross-reactivity between morphine and hydrocodone
- The severity and nature of the original morphine reaction
- The need for careful monitoring of the patient for adverse reactions
- The consideration of alternative non-opioid pain medications if there are concerns about cross-reactivity
- The importance of discussing the patient's specific morphine reaction with their healthcare provider to determine if hydrocodone is safe for them.
It is also important to note that hydrocodone is a schedule III opioid, and its use should be carefully considered in patients with a history of substance abuse or dependence 1. Additionally, the use of hydrocodone in patients with renal insufficiency or end-stage renal disease (ESRD) should be done with caution and with adjusted dosing, as recommended by the Society for Perioperative Assessment and Quality Improvement (SPAQI) consensus statement 1.
From the FDA Drug Label
CONTRAINDICATIONS Hydrocodone bitartrate and acetaminophen tablets are contraindicated in patients with: • Hypersensitivity to hydrocodone or acetaminophen (e.g., anaphylaxis) The patient has a morphine allergy, and the label mentions hypersensitivity to hydrocodone as a contraindication. Since morphine and hydrocodone are both opioids, and considering the potential for cross-reactivity, it is likely that a patient with a morphine allergy may also be allergic to hydrocodone. Therefore, a patient with a morphine allergy should not take hydrocodone 2.
From the Research
Opioid Allergy and Cross-Reactivity
- A patient with a morphine allergy may be concerned about taking hydrocodone, another opioid medication.
- According to a study on opioid cross-reactivity 3, the incidence of allergic cross-reactivity between clinical and chemical opioid classes in patients with historical IgE-mediated reactions (IMRs) was found to be low, ranging from 0% to 6.7%.
- This suggests that a patient with a morphine allergy may not necessarily be allergic to hydrocodone, as the cross-reactivity rate is relatively low.
Considerations for Hydrocodone Use
- However, it is essential to note that true allergic reactions to opioids are rare, but can occur 4.
- A detailed allergy history is crucial in determining whether a patient can receive a drug that may cross-react with another opioid 4.
- In the case of hydrocodone, it is a semi-synthetic opioid, and its structure is different from morphine, which may reduce the likelihood of cross-reactivity.
Clinical Implications
- A study on opioid analgesics-related pharmacokinetic drug interactions 5 found that none of the opioid-drug/herb pairs were listed as contraindications of opioids, including hydrocodone.
- However, the study also highlighted the importance of considering potential drug interactions and monitoring medication use in patients with opioid allergies.
- Clinicians should exercise caution when prescribing hydrocodone to a patient with a morphine allergy, and consider alternative pain management options if necessary 6, 7.