Although it is known that treatment for HIV has some side effects, a new study shows the drugs can cause toxic and adverse reactions. Swiss researchers studied 1,160 people treated for HIV infection. The patients were taking powerful antiretroviral treatments, including protease inhibitors and transcriptase inhibitors, two common HIV drugs. After measuring patients' blood and cholesterol, researchers found 47 per cent of patients experienced adverse effects from the antiretroviral therapy. The toxic reactions include kidney stones, kidney dysfunction, and severe fatigue. Among these patients, nine per cent to 16 per cent experienced severe adverse effects.