Thanks for your post.
There are a number of reasonable alternatives to stavudine (d4T, Zerit) in your patient. I'd agree with your apprehension about tenofovir (Viread, a component of Truvada and Atripla) because of the pre-existing risk factors for renal toxicity. Abacavir (Ziagen, part of Epzicom) would certainly be a viable option and has been very well studied in combination with efavirenz.
The distinguishing toxicity of abacavir is hypersensitivity reaction (HSR), and while fatalities have been observed with this reaction, appropriate and careful monitoring should prevent such severe outcomes. I look at abacavir as a drug (like many) that have the potential to cause allergic reactions. Such allergic reactions can be serious, but the majority of the issue comes not from first exposure to the medication, but rather from inadvertant rechallenge to the allergen. It may also be relevant to know that while the overall risk of HSR in the US and European population is ~5-8%, subpopulations (ie, Blacks) appear to be at significantly lower risks. HLA typing is increasingly used in some centers to pre-screen patients for their risk for HSR (though not FDA approved for this indication). Those persons who are negative for the HLA B57*01 marker are at dramatically lower risk of HSR. Taken together, in the appropriate patient and with appropriate monitoring, we've been using abacavir in our patients with clinical success.
Hope this helps. Feel free to write us back with any follow up questions. BY
