You may be allergic, or hypersensitive, to certain drugs. For example, some people are hypersensitive to abacavir (Ziagen, ABC, also found in Kivexa, Trizivir and Triumeq). A simple blood test, done before you start treatment, can determine whether you’re likely to have a potentially dangerous reaction to abacavir. If your test result is positive, you can cross that drug off your list of choices. If your test result is negative, a reaction is still possible but the risk is low.

Ask your healthcare provider about the signs of a hypersensitivity reaction so that you can seek medical help should you have such a reaction to abacavir or another HIV drug.