NURS 4380 PATHOPHYSIOLOGY,PHARMACOLOGY & PHYSICAL ASSESSMENT FINAL EXAM STUDY GUIDE Latest 2021/2022

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NURS 4380 PATHOPHYSIOLOGY,PHARMACOLOGY & PHYSICAL ASSESSMENT FINAL EXAM STUDY GUIDE Latest 2021/2022 Basics of Antibiotics (13) 1.Define selective toxicity as it applies to the general mechanism... s by which antibiotics work against invading pathogens but not against host cells. oSelective toxicity means that the drug interferes with necessary microbial biochemical processes. The pathogen is a prokaryote, while the host (us) is eukaryote, so their genetic makeup is different. •Explain disruption of bacterial cell wall (Ex: Penicillin and cephalosporins) ➢Prokaryotes (Bacteria) are encased in a rigid cell wall ➢The protoplasm within this wall has a high concentration of solutes, making osmotic pressure within high ➢Without this cell wall, bacteria would absorb water, swell, and then burst Several drug families weaken the cell wall and thereby promote bacterial lysis •Explain Inhibition of an enzyme unique to bacteria and provide example ➢Sulfonamides: Inhibit enzyme PABA (para-aminobenzoic acid), a precursor to folic acid, which is necessary for bacteria to synthesis folic acid; without this enzyme they die •Explain disruption of bacterial protein synthesis ➢Disrupts ribosomal protein synthesis but not in us because we have different ribosomes than bacteria 2.Give a working definition of narrow-spectrum and broad-spectrum antibiotics and state when one or the other would be preferred as a therapeutic approach and why. •Narrow spectrum: preferred to decrease chance of building resistance and superinfections. Doesn’t attack our normal bacteria (flora). Has high specificity- only attacks certain bacteria. This is what we want to use. •Broad spectrum: Kill many/all bacteria. Even normal bacteria die when these are used. Resistant bacteria flourish because nutrients help them thrive/multiply. Since everything else dies off, the resistant bacteria can use up all of the nutrients available. 1.Superinfection can occur. Ex: yeast infection bc normal flora is disrupted. 3.State the main mechanisms by which microbes develop resistance to antimicrobial drugs. Also, address the important issues of spontaneous mutations and R factors. oResistance: •Selection pressure occurs- resistant microbes flourish as sensitive microbes die off; Basically, on all humans there is a population of bacteria (Most are susceptible strains, and some are antibiotic-resistant). These bacteria compete with each other (for food and stuff) and your good normal flora fight off bad bacteria that doesn’t normally live on you. So, when a person takes antibiotics all of the susceptible strains are killed (which can be good or bad) but the resistant strains of bacteria survive. Because of this the remaining resistant strains do not have anyone to compete with, so they thrive because they now have no one to compete with for food or anyone trying to fight them off and if they are a bad microbe they can cause an infection on that person. •All antibiotics promote resistance [Show More]

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