Key Features of Abacavir Hypersensitivity
- Symptoms:
- Typically occur within the first 6 weeks of therapy (often within the first 2 weeks).
- Symptoms may include:
- Fever
- Rush
- Fatigue
- Gastrointestinal symptoms (nausea, vomiting, diarrhea, abdominal pain)
- Respiratory symptoms (shortness of breath, cough, sore throat)
- Symptoms can worsen with continued use of abacavir and may become life-threatening if not promptly addressed.
- HLA-B*57:01 Association:
- Genetic testing for the HLA-B*57:01 allele is recommended before starting abacavir.
- Individuals positive for this allele are at significantly increased risk of hypersensitivity.
- If the test is positive, abacavir should not be prescribed.
Management of Abacavir hypersensitivity
- Prevention:
- HLA-B*57:01 testing: All patients should be screened before initiating abacavir.
- Avoid prescribing abacavir to those with the HLA-B*57:01 allele.
- Recognizing Hypersensitivity:
- Early recognition of symptoms is critical.
- Providers should educate patients about the signs of hypersensitivity and the importance of reporting symptoms immediately.
- Discontinuation:
-
- Stop abacavir immediately if hypersensitivity is suspected.
- Do not reintroduce abacavir, as re-exposure can lead to rapid and severe symptoms, including anaphylaxis or death.
-
- Supportive Care:
-
-
- Treatment of symptoms (e.g., antipyretics for fever, antihistamines for rash).
- Close monitoring in severe cases, especially if respiratory or cardiovascular symptoms are present.
-
-
Rechallenge Risks of Abacavir Hypersensitivity
- Abacavir rechallenge is contraindicated in patients who experienced hypersensitivity, even if they test negative for HLA-B*57:01 afterward. Re-exposure can cause severe or fatal reactions.
Additional Considerations
- Patient Education:
- Patients should receive a warning card about abacavir hypersensitivity to carry at all times.
- Drug Alternatives:
- If abacavir cannot be used, other antiretroviral medications should be selected based on the patient’s HIV resistance profile.
If you are dealing with this situation, always consult a healthcare provider for appropriate testing and management.
Ask Question
Q. What is a hypersensitivity reaction to abacavir?
Ans. A hypersensitivity reaction to abacavir is a severe, immune-mediated response involving fever, rash, gastrointestinal symptoms, and respiratory distress. It typically occurs within six weeks of treatment and is associated with the HLA-B*5701 gene variant. Immediate discontinuation is essential.
Q. What is HLA B5701 abacavir hypersensitivity?
Ans. HLA-B5701 Abacavir hypersensitivity is a potentially life-threatening immune reaction triggered by abacavir in individuals with the HLA-B5701 gene variant. Symptoms include fever, rash, gastrointestinal distress, and respiratory issues. Genetic testing helps prevent this reaction before starting treatment.
Q. What are the side effects of abacavir HLA?
Ans. Side effects of abacavir in HLA-B*5701-positive individuals include hypersensitivity reactions characterized by fever, rash, fatigue, nausea, vomiting, diarrhea, abdominal pain, and respiratory symptoms. Severe cases may lead to multi-organ failure. Genetic screening minimizes these adverse effects.
Q. What HLA is associated with abacavir?
Ans. HLA-B5701 is associated with abacavir hypersensitivity. Individuals with this gene variant are at a significantly increased risk of developing severe immune-mediated reactions. Genetic testing for HLA-B5701 is recommended before initiating abacavir to prevent potentially life-threatening hypersensitivity reactions.
Q. Who should not take abacavir?
Ans. Individuals with the HLA-B5701 gene variant, a history of abacavir hypersensitivity, or severe liver impairment should not take abacavir. Genetic testing for HLA-B5701 is essential before treatment to avoid life-threatening hypersensitivity reactions.
Q. What are the cardiovascular risks of abacavir?
Ans. Abacavir may increase cardiovascular risks, including heart attack, particularly in individuals with existing risk factors like smoking or heart disease. The mechanism remains unclear, but careful evaluation of cardiovascular history is essential before prescribing abacavir-containing treatments.