8
Anti-infective agents
Learning objectives
Upon completion of this chapter, you should be able to:
1.
Explain what is meant by selective toxicity and discuss its importance in anti-infective therapies.
2.
Differentiate between broad-spectrum and narrow-spectrum drugs.
3.
Define bacterial resistance to antibiotics and discuss the emergence of resistant strains.
4.
Explain three ways to minimise bacterial resistance.
5.
Describe three common adverse reactions associated with the use of antibiotics.
Glossary of key terms
bactericidal:
substance that causes the death of bacteria, usually by interfering with cell membrane stability or with proteins or
enzymes necessary to maintain the cellular integrity of the bacteria
bacteriostatic:
substance that prevents the replication of bacteria, usually by interfering with proteins or enzyme systems necessary
for reproduction of the bacteria
culture:
sample of the bacteria (e.g. from sputum, cell scrapings, urine) to be grown in a laboratory to determine the species of bacteria
that is causing an infection
prophylaxis:
treatment to prevent an infection before it occurs, as in the use of antibiotics to prevent bacterial endocarditis or
antiprotozoals to prevent malaria
resistance:
ability of bacteria over time to adapt to an antibiotic and produce cells that are no longer affected by a particular drug
selective toxicity:
the ability to affect certain proteins or enzyme systems that are used by the infecting organism but not by human
cells
sensitivity testing:
evaluation of bacteria obtained in a culture to determine the antibiotics to which the organisms are sensitive and
which agent would be appropriate for treatment of a particular infection
spectrum:
range of bacteria against which an antibiotic is effective (e.g. broad-spectrum antibiotics are effective against a wide range
of bacteria)
superinfection:
infections that occur when opportunistic pathogens that were kept in check by the “normal” bacteria have the
opportunity to invade tissues and cause infections because the normal flora bacteria have been destroyed by antibiotic therapy
Test your current knowledge of anti-infective agents with a PrepU Practice Quiz!
DRUG LIST
chloramphenicol
meropenem
teicoplanin
vancomycin
