McKenna's Pharmacology for Nursing, 2e

88

P A R T 2  Chemotherapeutic agents

CHAPTER SUMMARY ■■ Anti-infectives are drugs designed to act on foreign organisms that have invaded and infected the human host with selective toxicity, which means that they affect biological systems or structures found in the invading organisms but not in the host. ■■ Anti-infectives include antibiotics, antivirals, antifungals, antiprotozoals and anthelmintic agents. ■■ The goal of anti-infective therapy is interference with the normal function of invading organisms to prevent them from reproducing and promotion of cell death without negative effects on the host cells. The infection should be eradicated with the least toxicity to the host and the least likelihood for development of resistance. ■■ Anti-infectives can work by altering the cell membrane of the pathogen, by interfering with protein synthesis or by interfering with the ability of the pathogen to obtain needed nutrients. ■■ Anti-infectives also work to kill invading organisms or to prevent them from reproducing, thus depleting the size of the invasion to one that can be dealt with by the human immune system. ■■ Pathogens can develop resistance to the effects of anti-infectives over time when (1) mutant organisms that do not respond to the anti-infective become the majority of the pathogen population or (2) the pathogen develops enzymes to block the anti-infectives or alternative routes to obtain nutrients or maintain the cell membrane. ■■ An important aspect of clinical care involving anti-infective agents is preventing or delaying the development of resistance. This can be done by ensuring that the particular anti-infective agent is the drug of choice for the specific pathogen involved and that it is given in high enough doses for sufficiently long periods to rid the body of the pathogen. ■■ Culture and sensitivity testing of a suspected infection ensures that the correct drug is being used to treat the infection effectively. Culture and sensitivity testing should be performed before an anti-infective agent is prescribed. ■■ Anti-infectives can have several adverse effects on the human host, including renal toxicity, multiple GI effects, neurotoxicity, hypersensitivity reactions and superinfections. ■■ Some anti-infectives are used as a means of prophylaxis when people expect to be in situations that will expose them to a known pathogen, such as travel to an area where malaria is endemic, or oral or invasive GI surgery in a person who is susceptible to subacute bacterial endocarditis.

ONLINE RESOURCES

An extensive range of additional resources to enhance teaching and learning and to facilitate understanding of this chapter may be found online at the text’s accompanying website, located on thePoint at http://thepoint.lww.com. These include Watch and Learn videos, Concepts in Action animations, journal articles, review questions, case studies, discussion topics and quizzes.

WEB LINKS

Healthcare providers and students may want to consult the following Internet sources: www.health.gov.au/internet/main/publishing.nsf/ content/cda-cdi3303e.htm Department of Health and Ageing. Tuberculosis in Australia. www.nps.org.au/about-us/what-we-do/ campaigns-events/antibiotic-resistance-fighter National Prescribing Service. Antibiotic Resistance. www.who.int/mediacentre/factsheets/fs194/en World Health Organization. Antimicrobial Resistance. BIBLIOGRAPHY Bassler, B. & Winans, S. C. (2008). Chemical Communication Among Bacteria. Hoboken, New Jersey: John Wiley & Sons. Farrell, M. & Dempsey, J. (2014). Smeltzer & Bare’s Textbook of Medical-Surgical Nursing (3rd edn). Sydney: Lippincott, Williams & Wilkins. Gillespie, E., Rodrigues, A., Wright, L., Williams, N. & Stuart, R. L. (2013). Improving antibiotic stewardship by involving nurses. American Journal of Infection Control, 41(4), 365–367. McKenna, L. (2012). Pharmacology Made Incredibly Easy (1st Australian and New Zealand edn). Sydney: Lippincott Williams & Wilkins. McKenna, L. & Mirkov, S. (2014). McKenna’s Drug handbook for Nursing and Midwifery (7th edn). Sydney: Lippincott Williams & Wilkins. McKenzie, D., Rawlins, M. & Del Mar, C. (2013). Antimicrobial stewardship: What’s it all about? Australian Prescriber, 36(4) , 116–120. Porth, C. M. (2011). Essentials of Pathophysiology: Concepts of Altered Health States (3rd edn). Philadelphia: Lippincott Williams & Wilkins. Porth, C. M. (2009). Pathophysiology: Concepts of Altered Health States (8th edn). Philadelphia: Lippincott Williams & Wilkins. RHD Australia, National Heart Foundation of Australia and the Cardiac Society of Australia and New Zealand. (2012). Australian Guideline for Prevention, Diagnosis and Management of Acute Rheumatic Fever and Rheumatic Heart Disease (2nd edn). www.rhdaustralia.org.au/sites/default/files/ guideline0.pdf. Turnidge, J. (2010). Multiresistant organisms at the front line. Australian Prescriber, 33(3) , 68–71. World Health Organisation. (2013). Antimicrobial resistance. Fact Sheet No. 194. www.who.int/mediacentre/factsheets/fs194/en.

Knowing your strengths and weaknesses helps you to study more effectively. Take a PrepU Practice Quiz to find out how you measure up!