1. Before taking an HIV med containing abacavir, have a blood test to screen for a gene called HLA-B*5701. People with that gene may be more likely to have a dangerous allergic reaction to abacavir (if the drug is stopped and then restarted, the reaction can be fatal). Those with HLA-B*5701 will likely want to choose a different med.

2. Some studies have shown that abacavir may elevate the danger of heart attacks in people already at risk for cardiovascular disease (CVD). Anyone planning to start the med should be screened for CVD risks such as high blood pressure, diabetes and high cholesterol and triglycerides. Smoking, which significantly raises CVD risk, is a factor too—so why not quit?