Chapter 15 - Antimicrobial Drugs
questions well answered
Define antimicrobial drugs. - correct answer ✔✔ •Antimicrobial drugs are therapeutic
compounds that kill microbes or inhibit their growth
Explain how Alexander Fleming discovered penicillin and name the genus of the fungus that
makes this antibiotic. - correct answer ✔✔ •Alexander Fleming (1928)
-Studied Staphylococcus aureus
-Noticed a plate was contaminated
-S. aureus were unable to grow near the mold
-Mold excreted a compound that could inhibit the bacteria
-Penicillin was mass-produced by the 1940s
Define antibacterial drugs, antiviral drugs, antifungal drugs, and antiparasitic drugs. - correct
answer ✔✔ -Antibacterial drugs - treat bacterial infections
-Antiviral drugs - target viral infections
-Antifungal drugs - target fungal infections
-Antiparasitic drugs - treat protozoan and helminthic (worm) infections
Define the terms broad spectrum and narrow spectrum as they relate to antimicrobials. -
correct answer ✔✔ •Broad-spectrum drugs
-Effective against Gram-negative and Gram-positive bacteria
•Narrow-spectrum drugs
-Target a limited range of bacteria
-Usually preferred because they present less disruption to the normal microbiota
,Compare bacteriostatic to bactericidal drugs, discuss scenarios where each may be useful. -
correct answer ✔✔ -Bacteriostatic
*Prevent bacteria from growing
*Tend to target bacterial protein synthesis and metabolic pathways
-Bactericidal
*Kill bacteria
*Tend to target bacterial cell walls or cell membranes and nucleic acids
*Possible drawbacks: kills normal microbiota and may lead to release of LPS
Describe the terms natural, semisynthetic, and synthetic antimicrobials and state the potential
value of drug modifications. - correct answer ✔✔ •Antibiotics
-Naturally occurring antimicrobial compounds
•Synthetic antimicrobials
-Manufactured by chemical processes
•Semisynthetic antimicrobials
-Chemical modification of naturally occurring antibiotics
What is meant by first- and second-generation drugs? - correct answer ✔✔ •First-generation
drugs
-Drugs that result from a first round of chemical modification
•Second-generation drugs
-Drugs resulting from a second round of chemical modification
Define the following and discuss how they relate to drug development: therapeutic index,
selective toxicity, and drug half-life. - correct answer ✔✔ •Therapeutic index (TI)
-Ratio of the maximum safe dose to the minimum therapeutic dose
, -High TI = safe
-Low TI = risky
*"Selective toxicity" refers to the ability of an antimicrobial drug to harm the target microbe
without harming the host.
•Half-life
-Time it takes for half of a dose to be eliminated or deactivated by the body
-Half-life determines frequency of administration
*Short half-life requires frequent administration
*Long half-life doesn't need to be taken as frequently
-Examples:
*Penicillin V has a half-life of 30 minutes
-Taken every 4 hours for 7-10 days
*Azithromycin has a half-life of up to 68 hours
-Taken every 24 hours for 3-5 days
Discuss hepatotoxicity and nephrotoxicity as they relate to antimicrobials and provide examples
of drug classes associated with each effect. - correct answer ✔✔ •Nephrotoxic (or kidney-toxic)
-Leading agents of drug-induced nephropathy
-Aminoglycosides and extended use of NSAIDs
•Hepatotoxic (or liver-toxic)
-Leading agents of drug-induced liver injury (DILI)
-DILI is the most commonly cited reason for discontinuing drug development or removing a drug
from the market
questions well answered
Define antimicrobial drugs. - correct answer ✔✔ •Antimicrobial drugs are therapeutic
compounds that kill microbes or inhibit their growth
Explain how Alexander Fleming discovered penicillin and name the genus of the fungus that
makes this antibiotic. - correct answer ✔✔ •Alexander Fleming (1928)
-Studied Staphylococcus aureus
-Noticed a plate was contaminated
-S. aureus were unable to grow near the mold
-Mold excreted a compound that could inhibit the bacteria
-Penicillin was mass-produced by the 1940s
Define antibacterial drugs, antiviral drugs, antifungal drugs, and antiparasitic drugs. - correct
answer ✔✔ -Antibacterial drugs - treat bacterial infections
-Antiviral drugs - target viral infections
-Antifungal drugs - target fungal infections
-Antiparasitic drugs - treat protozoan and helminthic (worm) infections
Define the terms broad spectrum and narrow spectrum as they relate to antimicrobials. -
correct answer ✔✔ •Broad-spectrum drugs
-Effective against Gram-negative and Gram-positive bacteria
•Narrow-spectrum drugs
-Target a limited range of bacteria
-Usually preferred because they present less disruption to the normal microbiota
,Compare bacteriostatic to bactericidal drugs, discuss scenarios where each may be useful. -
correct answer ✔✔ -Bacteriostatic
*Prevent bacteria from growing
*Tend to target bacterial protein synthesis and metabolic pathways
-Bactericidal
*Kill bacteria
*Tend to target bacterial cell walls or cell membranes and nucleic acids
*Possible drawbacks: kills normal microbiota and may lead to release of LPS
Describe the terms natural, semisynthetic, and synthetic antimicrobials and state the potential
value of drug modifications. - correct answer ✔✔ •Antibiotics
-Naturally occurring antimicrobial compounds
•Synthetic antimicrobials
-Manufactured by chemical processes
•Semisynthetic antimicrobials
-Chemical modification of naturally occurring antibiotics
What is meant by first- and second-generation drugs? - correct answer ✔✔ •First-generation
drugs
-Drugs that result from a first round of chemical modification
•Second-generation drugs
-Drugs resulting from a second round of chemical modification
Define the following and discuss how they relate to drug development: therapeutic index,
selective toxicity, and drug half-life. - correct answer ✔✔ •Therapeutic index (TI)
-Ratio of the maximum safe dose to the minimum therapeutic dose
, -High TI = safe
-Low TI = risky
*"Selective toxicity" refers to the ability of an antimicrobial drug to harm the target microbe
without harming the host.
•Half-life
-Time it takes for half of a dose to be eliminated or deactivated by the body
-Half-life determines frequency of administration
*Short half-life requires frequent administration
*Long half-life doesn't need to be taken as frequently
-Examples:
*Penicillin V has a half-life of 30 minutes
-Taken every 4 hours for 7-10 days
*Azithromycin has a half-life of up to 68 hours
-Taken every 24 hours for 3-5 days
Discuss hepatotoxicity and nephrotoxicity as they relate to antimicrobials and provide examples
of drug classes associated with each effect. - correct answer ✔✔ •Nephrotoxic (or kidney-toxic)
-Leading agents of drug-induced nephropathy
-Aminoglycosides and extended use of NSAIDs
•Hepatotoxic (or liver-toxic)
-Leading agents of drug-induced liver injury (DILI)
-DILI is the most commonly cited reason for discontinuing drug development or removing a drug
from the market
