NURS 6521 Wk 8 Antimicrobial Agents
There are several factors which must be considered when choosing appropriate antimicrobial agents to treat an infection. Empiric antimicrobial treatment is aimed at treating the most likely infectious organisms. Gram stains and culture and sensitivity studies help identify the organism and its susceptibility. In the end, efficacy, toxicity, pharmacokinetic profile, and cost determine which antimicrobial to use. The ideal dose and duration of treatment are influenced by patient factors like age, weight, other diseases the patient may have and the site and severity of the infection (Arcangelo, Peterson, Wilbur, & Reinhold, 2017).NURS 6521 Wk 8 Antimicrobial Agents
Categories of Antimicrobial Agents
Penicillins, cephalosporins, monobactams, carbapenems, and the beta-lactam/beta-lactamase inhibitor combinations interfere with cell wall growth by binding to and inactivating the penicillin-binding proteins(PBP). Fluoroquinolones are inhibitors of DNA gyrase and topoisomerase, which prevents the bacterial DNA from replicating. Macrolides, ketolides, aminoglycosides, tetracyclines, glycylcyclines, streptogramins, anti-anaerobic agents (clindamycin), Chloramphenicol and oxazolidinones inhibit bacterial protein synthesis by binding to ribosome subunits. Sulfonamides inhibit folic acid synthesis required for bacterial cell growth. Glycopeptides are also cell-wall active but through a different process than those that inactivate PBPs. Daptomycin is the only lipopeptide antibiotic, and its action is different than any other antibiotic. Lipopeptides cause depolarization of bacterial membrane potential which leads to cell death. Metronidazole is categorized as an anti-anaerobic agent; it causes DNA strands to break which results in protein synthesis inhibition. Rifampin is a macrocyclic antibiotic which suppresses RNA synthesis. Nitrofurantoin’s mechanism of action is not well understood. It inhibits bacterial enzymes which also causes impaired cell wall synthesis (Arcangelo, Peterson, Wilbur, & Reinhold, 2017). NURS 6521 Wk 8 Antimicrobial Agents
Many of the antibiotics overlap in the infections that they treat. Bacteria are classified as gram-negative or positive, aerobic or anaerobic, and by the resistance, they have developed. Each group of antibiotics treats specific types of bacteria and often target different areas of the body, such as skin or lungs. It is important to get the right type of coverage for the pathogen (Arcangelo, Peterson, Wilbur, & Reinhold, 2017).
Differences Between Viral and Bacterial Infections
It is important to be able to distinguish between a bacterial and viral infection. Antibiotics are ineffective against viruses. Antibiotics either kill bacteria or stop them from multiplying. Overuse of antibiotic therapy has led to an increase in bacterial drug resistance. Bacteria and viruses can cause similar symptoms and are often spread in the same way (Health Direct, 2016). Most viral infections are managed by treating the symptoms. These treatments are usually over-the-counter preparations.
Proper Identification of Infections is Key to Selecting the Proper Antimicrobial Agent
It is important because antibiotics do not treat viruses and anti-virals do not treat bacterial infections. “At least 80 million antibiotic prescriptions each year are unnecessary, which makes improving antibiotic prescribing and use a national priority” (Centers for Disease Control and Prevention, 2018). “Antibiotic resistance is one of the most serious public health problems in the United States and threatens to return us to the time when simple infections were often fatal. When we optimize how we use and prescribe these drugs, we protect patients from harm and combat antibiotic resistance” (Centers for Disease Control and Prevention, 2017). NURS 6521 Wk 8 Antimicrobial Agents
References
Arcangelo, V. P., Peterson, A. M., Wilbur, V., & Reinhold, J. A. (2017). Pharmacotherapeutics for Advanced Practice: A Practical Approach. Philadelphia: Wolters Kluwer.
Centers for Disease Control and Prevention. (2017, September 25). Antibiotics prescribing and use in doctor’s offices. Retrieved from www.cdc.gov: https://www.cdc.gov/antibiotic-use/community/index.html
Centers for Disease Control and Prevention. (2018, April 6). Antibiotic prescribing and use. Retrieved from CDC.gov: https://www.cdc.gov/antibiotic-use/
Health Direct. (2016, May). Differences between bacterial and viral infection. Retrieved from Healthdirect.gov.au: https://www.healthdirect.gov.au/bacterial-vs-viral-infection NURS 6521 Wk 8 Antimicrobial Agents