Antibiotics are medicines that fight infection by killing bacteria or by stopping them from growing or multiplying. They can be taken by mouth (as pills, capsules, or liquids), on the skin (as creams, sprays, ointments, and eye drops) or through an injection or intravenously. They can treat a wide range of infections, such as earaches, strep throat, and urinary tract infections.
When antibiotics are used correctly, they can speed healing and reduce the risk of complications, such as yeast infections or diarrhea. However, when antibiotics are taken too often or for minor infections that would go away on their own, they can cause side effects and contribute to the development of resistant bacteria.
Doctors and patients both play a role in how antibiotics are used. Many factors influence the overuse of antibiotics, including patient demands and expectations, lack of access to diagnostic tests, and economic incentives for physicians to prescribe drugs that aren’t necessary or don’t work.
Overuse of antibiotics can also promote resistance by allowing bacteria to develop properties that help them survive the drug’s attack, or by promoting the growth of harmful bacteria that can replace the targeted bacteria. To decrease the development of resistant bacteria, it’s important to take all prescribed antibiotics exactly as instructed — for the full course of treatment.
For example, some types of antibiotics, such as cephalosporins, are designed to work against a broad spectrum of bacteria. Others, such as the aminoglycosides and tetracyclines, bind to and inhibit protein synthesis in bacteria. And the quinolones interrupt DNA replication in bacteria.