What are the symptoms of an allergic reaction to Gabapentin (Neurontin)?

From the Guidelines

If you suspect a gabapentin allergic reaction, stop taking the medication immediately and seek medical attention, especially if symptoms are severe. Allergic reactions to gabapentin are uncommon but can range from mild (skin rash, itching, hives) to severe (difficulty breathing, swelling of face/throat, anaphylaxis) 1. Other possible side effects that might be confused with allergies include dizziness, drowsiness, and peripheral edema.

Key Considerations

• If you experience a mild reaction, contact your healthcare provider for guidance; they may recommend antihistamines for symptom relief or prescribe an alternative medication such as pregabalin, carbamazepine, or amitriptyline depending on your condition 1.
• Never stop gabapentin suddenly without medical supervision as this can trigger withdrawal symptoms.
• Allergic reactions occur because your immune system mistakenly identifies the drug as harmful, releasing chemicals that cause inflammatory symptoms.
• Always inform healthcare providers about this allergy for future medical records, and consider wearing a medical alert bracelet if the reaction was severe.

Management of Allergic Reactions

• For severe reactions, epinephrine administered intramuscularly is the first-line treatment 1.
• Antihistamines and glucocorticoids may also be used in anaphylaxis management, although their role is not clearly established 1.
• In cases of biphasic anaphylaxis, recurrent anaphylaxis may occur 1 to 72 hours after resolution of the initial episode, and antihistamines and glucocorticoids may affect this outcome 1.

From the FDA Drug Label

Warnings and Precautions 5. 1 Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), also known as multiorgan hypersensitivity, has occurred with gabapentin. 5. 2 Anaphylaxis and Angioedema Gabapentin can cause anaphylaxis and angioedema after the first dose or at any time during treatment.

Gabapentin Allergic Reaction:

• Gabapentin can cause anaphylaxis and angioedema after the first dose or at any time during treatment.
• DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms), also known as multiorgan hypersensitivity, has occurred with gabapentin.
• Signs and symptoms of an allergic reaction to gabapentin may include:
  • Difficulty breathing
  • Swelling of the lips, throat, and tongue
  • Hypotension requiring emergency treatment
  • Fever
  • Rash
  • Lymphadenopathy
  • Hepatitis
  • Nephritis
  • Hematological abnormalities
  • Myocarditis
  • Myositis
• Patients should be instructed to discontinue gabapentin and seek immediate medical care should they experience signs or symptoms of an allergic reaction 2.
• Gabapentin tablets may cause serious or life-threatening allergic reactions that may affect your skin or other parts of your body, such as your liver or blood cells 2.

From the Research

Gabapentin Allergic Reaction

• Gabapentin is a medication that can cause allergic reactions, including hypersensitivity syndrome, which is a rare but potentially fatal reaction 3.
• The symptoms of gabapentin-induced hypersensitivity syndrome can include fever, rash, tender lymphadenopathy, hepatitis, and eosinophilia, and can begin several days after starting the medication 3.
• Anaphylaxis is a severe, life-threatening allergic reaction that can be caused by medications, including gabapentin, and requires prompt treatment with epinephrine 4, 5, 6.
• The management of anaphylaxis typically involves the use of epinephrine, antihistamines, and corticosteroids, although the evidence for the use of corticosteroids is limited 4, 5, 6.
• Patients who experience an allergic reaction to gabapentin should discontinue the medication and seek medical attention immediately 3.

Treatment and Management

• Epinephrine is the first-line treatment for anaphylaxis, and its prompt use can help to prevent severe reactions and improve outcomes 4, 5, 6.
• Antihistamines and corticosteroids may also be used to treat anaphylaxis, although their effectiveness is not as well established as that of epinephrine 4, 5, 6.
• Patients who are at risk of anaphylaxis should be provided with structured, comprehensive training on the use of adrenaline autoinjectors and the management of anaphylaxis 6.

Interactions and Precautions

• Gabapentin can interact with other medications, including antiepileptic drugs, and patients should be monitored for potential interactions and side effects 7.
• Patients who are taking gabapentin should be aware of the potential for allergic reactions and should seek medical attention immediately if they experience any symptoms of anaphylaxis or hypersensitivity syndrome 3.