Antibiotics may stamp out bacterial infections, but when taken for long periods of time these drugs stamp like bulls in a china shop kicking up side effects varying in severity from headache to hearing loss.

In this week's issue of Science Translational Medicine, scientists from Harvard University's Wyss Institute for Biologically Inspired Engineering published findings showing how antibiotics that kill bacteria can cause oxidative stress in cultures of human cells, and in cells of mice. As Science Daily reports, researchers tested two strategies for avoiding these side effects.

"Clinical levels of antibiotics can cause oxidative stress that can lead to damage to DNA, proteins and lipids in human cells, but this effect can be alleviated by antioxidants," said Jim Collins, Ph.D., who led the study. ... [Researchers] were able to prevent oxidative stress by using a bacteriostatic antibiotic -- an antibiotic such as tetracycline that stops bacteria from multiplying but doesn't kill them. They could also ease oxidative stress by mopping up chemically reactive oxygen molecules with an FDA-approved antioxidant called N-acetylcysteine, or NAC, that's already used to help treat children with cystic fibrosis.

Researchers say further animal studies are needed to determine the optimal ways for correcting oxidative stress related to long-term antibiotic use.

Holly MacCormick is a writing intern in the medical school’s Office of Communication & Public Affairs. She is a graduate student in ecology and evolutionary biology at University of California-Santa Cruz.

Previously: New method may speed identification of antibiotic targets,“Clinical trial in a dish” may make common medicines safer, say Stanford scientists, Image of the Week: Bacterial growth in multicolor and Harnessing evolutionary forces to develop more effective methods for treating superbugs