Management of Injection Site Reactions to Aimovig (Erenumab) 70 mg/mL
Primary Recommendation
Injection site reactions to Aimovig are common (occurring in up to 14-15% of patients with subcutaneous biologics), generally mild, self-limited, and do not require discontinuation of therapy. 1, 2
Clinical Characteristics of Expected Injection Site Reactions
Pain and redness at the injection site lasting 1-2 days are the most frequent local reactions, occurring in 4-56% of patients receiving subcutaneous biologics, with most reactions resolving spontaneously without intervention. 1
Injection site reactions with subcutaneous monoclonal antibodies are typically grade 1 according to CTCAE criteria (mild, requiring no intervention), with grade 2 reactions (moderate, requiring minimal intervention) being rare. 3
These reactions diminish with ongoing therapy and do not correlate with antibody development or treatment failure. 1
Immediate Management Algorithm
For Mild Local Reactions (Pain, Redness, Swelling)
Apply cold compresses to the injection site for 10-15 minutes to reduce local inflammation and discomfort. 1
Administer oral antihistamines (e.g., diphenhydramine 25-50 mg or cetirizine 10 mg) if pruritus or mild urticaria develops at the injection site. 1
Continue Aimovig therapy without dose modification, as mild injection site reactions do not predict treatment failure and typically decrease with subsequent injections. 1, 3
For Severe or Systemic Reactions (Anaphylaxis, Angioedema)
Discontinue Aimovig immediately and do not rechallenge if anaphylaxis (severe, life-threatening systemic hypersensitivity) or angioedema occurs. 2
Administer intramuscular epinephrine 0.3-0.5 mg (1:1000 dilution) for anaphylaxis, with repeat dosing every 5-15 minutes as needed, and transfer to emergency care. 1
Hypersensitivity reactions to Aimovig, including anaphylaxis and angioedema, have been reported in postmarketing surveillance and typically occur within hours of administration, though some occur more than one week later. 2
Prevention Strategies for Future Injections
Allow Aimovig to reach room temperature for at least 30 minutes before injection (protected from direct sunlight), as this minimizes injection discomfort and ensures complete dose delivery. 2
Rotate injection sites among the abdomen, thigh, and upper arm, avoiding areas where skin is tender, bruised, red, or hard. 2
Use proper aseptic technique and ensure the patient or caregiver receives training on subcutaneous injection administration to minimize trauma and infection risk. 2
Do not warm Aimovig using heat sources (hot water, microwave) or shake the product, as this may denature the protein and increase local reactions. 2
When to Escalate or Modify Treatment
Discontinue Aimovig if serious hypersensitivity reactions occur (anaphylaxis, angioedema, severe urticaria), as these are absolute contraindications to continued therapy. 2
Consider switching to an alternative CGRP monoclonal antibody (fremanezumab, galcanezumab, eptinezumab) if injection site reactions are intolerable but not severe, as failure of one CGRP antagonist does not predict failure of others. 4, 5
Persistent mild injection site reactions (grade 1) are not an indication to discontinue therapy, as they occur in up to one-third of patients and do not affect treatment efficacy. 3
Monitoring and Follow-Up
Assess injection site reactions at each follow-up visit (typically at 3 months, 6 months, and 12 months), documenting severity using CTCAE grading to track trends over time. 3
Injection site reactions remain stable over 12 months of treatment (occurring in 32-37% of patients at any time point), with no evidence of habituation or worsening with continued therapy. 3
Female patients and those with migraine with aura may report more frequent adverse events, including injection site reactions, though these remain mild and do not require treatment modification. 3
Critical Pitfalls to Avoid
Do not discontinue Aimovig for mild, self-limited injection site reactions, as these are expected, benign, and decrease with ongoing therapy. 1, 3
Do not fail to distinguish between mild local reactions and serious systemic hypersensitivity, as the latter requires immediate discontinuation and emergency management. 2
Do not administer Aimovig cold directly from the refrigerator, as this increases injection discomfort and may lead to incomplete dose delivery. 2
Do not rechallenge with Aimovig after anaphylaxis or angioedema, as these are absolute contraindications and repeat exposure may result in life-threatening reactions. 2