Pharmacogenetics Newsletter

Volume 1, Issue 3, 03/04/2009

Question

How does a patient's genetics predispose them to abacavir (Ziagen®) induced hypersensitivity reaction that prevents future use of the drug for the treatment of HIV infection?

Answer

Abacavir (Ziagen®) is a well known nucleoside reverse transcriptase inhibitor (NRTI) used in combination with other antiretrovirals for the treatment of HIV infection.  Unfortunately, approximately 8% (range, 2 to 9%) of patients are known to develop a clinically significant hypersensitivity (allergic) reaction within the first 6 weeks of therapy that requires discontinuation of abacavir.  Due to escalating concern of hypersensitivity reactions as well as increased cardiovascular disease risk, the Department of Health and Human Services (DHHS) Panel on Antiretroviral Guidelines for Adults and Adolescents moved abacavir from the list of preferred NRTIs to an alternative NRTI.(1)  Patients who experience an abacavir-induced hypersensitivity reaction should never be rechallenged. This hypersensitivity reaction is characterized by having 2 or more of the following signs or symptoms: fever, rash, gastrointestinal symptoms (such as nausea, vomiting, diarrhea, or abdominal pain), constitutional symptoms (such as generalized malaise, fatigue) and/or respiratory symptoms (such as dyspnea, cough, or pharyngitis).(2)   So if only 8% of patients experience this reaction, are there any common characteristics that can be used to indentify high risk patients?......To read the full answer please LOGIN or SUBSCRIBE NOW.