Drug resistance (such as antibiotic resistance) occurs when
disease-causing organisms change over time and adapt in ways that allow them to
survive exposure to a medication that once killed or
controlled them.
Many forms of bacteria have become resistant to common antibiotics
designed to kill them. These are called
antibiotic-resistant bacteria. For example, several strains of the bacteria
that cause tuberculosis and sinus, ear, and lung infections can no longer be
killed by many antibiotics. Other illnesses, such as malaria and gonorrhea,
also have drug-resistant strains of organisms.
Frequent and/or inappropriate use of antibiotics leads to the
development of drug-resistant bacteria. For example, taking antibiotics when
they may not be needed, using them for a nonbacterial infection (such as a
cold), or not taking all of an antibiotic as directed may promote the
development of antibiotic-resistant strains of bacteria.
