 The most common side effects of abacavir/lamivudine/zidovudine include nausea, vomiting, diarrhea, fatigue, paresthesias and headache.As with many medications targeting reverse transcriptase, body fat redistribution syndrome may occur, causing body fat to center on the upper back and neck, breast, and torso, and potentially decreasing around the legs, arms, and face.IRIS may occur which is when the immune system initially improves, but then deteriorates as a previously ignored infection becomes active.