Copyright 2017 Wolters Kluwer All Rights Reserved Anti Infective Activity Anti

Copyright © 2017 Wolters Kluwer • All Rights Reserved Anti-Infective Activity Anti-Infective Activity • Anti-infectives vary in their effectiveness against invading organisms. • Some are selective – only effective for a few number of organisms • Bactericidal – kill the cell • Bacteriostatic – prevent reproduction of the cell

Copyright © 2017 Wolters Kluwer • All Rights Reserved Narrow Spectrum vs. Broad Spectrum Narrow Spectrum vs. Broad Spectrum • Narrow Spectrum of Activity – Effective against only a few microorganisms with a very specific metabolic pathway or enzyme • Broad Spectrum of Activity – Useful in treating a wide variety of infections

Copyright © 2017 Wolters Kluwer • All Rights Reserved Human Immune Response Human Immune Response • Goal of anti-infective therapy is reduction of the population of the invading organism. • Drugs that would eliminate all traces of any invading pathogen might be toxic to the host as well. • Immune response is a complex process involving chemical mediators, leukocytes, lymphocytes, antibodies, and locally released enzymes and chemicals.

Copyright © 2017 Wolters Kluwer • All Rights Reserved Resistance Resistance • Natural or acquired: Ability over time to adapt to an anti- infective drug and produce cells that are no longer affected by a particular drug. • Anti- infectives act on specific enzyme system or biological process, many microorganisms that do not act on this system are not affected by this particular drug

Copyright © 2017 Wolters Kluwer • All Rights Reserved Acquired Resistance Acquired Resistance • Microorganisms that were once sensitive to the particular drug have begun to develop acquired resistance. • This results in serious clinical problems.

Copyright © 2017 Wolters Kluwer • All Rights Reserved Ways Anti-Infective Agents Resistance Develops Ways Anti-Infective Agents Resistance Develops • Producing an enzyme that deactivates the antimicrobial drug • Changing cellular permeability to prevent the drug from entering the cell • Altering transport systems to exclude the drug from active transport into the cell • Altering binding sites on the membranes or ribosomes, which then no longer accept the drug • Producing a chemical that acts as an antagonist to the drug

Copyright © 2017 Wolters Kluwer • All Rights Reserved Question Question Which of the following has been found to be as important as drug therapy when treating infections in the immunosuppressed? A. Maintaining standard precautions B. Proper nutrition C. Good hand washing D. Exercise

Copyright © 2017 Wolters Kluwer • All Rights Reserved Answer Answer B. Proper nutrition Rationale: In helping these people (the immunosuppressed) cope with infections, prevention of infection and proper nutrition are often as important as drug therapy.