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Ch. 20 - Antimicrobial Drugs
Tortora - Microbiology: An Introduction 14th Edition
Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398Not the one you use?Change textbook
All textbooksTortora 14th EditionCh. 20 - Antimicrobial DrugsProblem 3
Chapter 20, Problem 3

What similar problems are encountered with antiviral, antifungal, antiprotozoan, and antihelminthic drugs?

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1
Identify the common challenges faced by antimicrobial drugs targeting viruses, fungi, protozoa, and helminths by considering their biological differences from bacteria and human cells.
Understand that one major problem is selective toxicity, which means the drug must harm the pathogen without damaging the host's cells; this is difficult because these pathogens are eukaryotic (like human cells) or have complex life cycles.
Recognize that drug resistance can develop in these pathogens, similar to bacteria, making treatment less effective over time.
Consider the issue of toxicity and side effects, as drugs targeting eukaryotic pathogens often affect human cells due to similarities, leading to adverse reactions.
Note that the complexity of the pathogens' life cycles and their ability to hide within host cells or tissues can make it difficult for drugs to reach and effectively eliminate them.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Selective Toxicity

Selective toxicity refers to the ability of a drug to target pathogens without harming the host. Antiviral, antifungal, antiprotozoan, and antihelminthic drugs often struggle with this because these pathogens share many cellular features with human cells, making it difficult to kill the pathogen without damaging host tissues.
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Drug Resistance

Drug resistance occurs when pathogens evolve mechanisms to survive exposure to drugs designed to kill them. This is a common problem across antiviral, antifungal, antiprotozoan, and antihelminthic treatments, leading to reduced drug efficacy and the need for new or combination therapies.
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Limited Drug Targets

Many eukaryotic pathogens and viruses have fewer unique biochemical pathways or structures compared to bacteria, limiting the number of effective drug targets. This scarcity complicates the development of drugs that can specifically inhibit these pathogens without affecting human cells.
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Related Practice
Textbook Question

Which of the following modes of action would not be fungicidal?

a. Inhibition of peptidoglycan synthesis

b. Inhibition of mitosis

c. Injury to the plasma membrane

d. Inhibition of nucleic acid synthesis

e. All of the above are fungicidal modes of action

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Textbook Question

All of the following are modes of action of antiviral drugs except:

a. Inhibition of protein synthesis at 70S ribosomes

b. Inhibition of DNA synthesis

c. Inhibition of RNA synthesis

d. Inhibition of uncoating

e. All of the above are modes of action of antiviral drugs

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Textbook Question

The most selective antimicrobial activity would be exhibited by a drug that:

a. Inhibits cell wall synthesis

b. Inhibits protein synthesis

c. Injures the plasma membrane

d. Inhibits nucleic acid synthesis

e. All of the above

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Textbook Question

Define drug resistance. How is it produced? What measures can be taken to minimize drug resistance?

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Textbook Question

List and explain five criteria used to identify an effective antimicrobial agent.

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Textbook Question

An antimicrobial agent should meet all of the following criteria except:

a. Selective toxicity

b. The production of hypersensitivities

c. A narrow spectrum of activity

d. No production of drug resistance

e. All of the above are necessary criteria for an antimicrobial

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