Exam 3: Quiz--Controlling Microbial Growth in Body: Antimicrobial Drugs Flashcards
What are chemicals that affect physiology in any manner called?
Drugs
includes all medications, also caffeine, alcohol, tobacco
What are drugs that act against disease?
Chemotherapeutic agents
Exs:
insulin, anticancer drugs, antimicrobials, etc.
What are drugs that treat infections?
anitmicrobial agents
Exs:
antibiotics, antivirals, antiprotozoans, antifungals, antihelminthics
What is a subcategory to Drugs? What is a subcategory to that?
Drugs–> Chemotherapeutic agents–> antimicrobial agents
What is the key to mechanisms of antimicrobial action?
Selective toxicity
What is the term for a drug that is more toxic to pathogen than to pathogen’s host?
selective toxicity
What is the largest and most diverse kind of drugs?
antibacterial
What kind of drugs do we have most of? list in order.
- eukaryotic infs
- bacterial infs
- viral infs
- Antibacterial
- Eukaryotic infs (antifungal, antiprotozoan, antihelminthic)
- antiviral drugs
What type of drugs do we have the fewest of?
anitviral drugs
What are the 6 Mechanisms of Action of Antimicrobial Drugs?
- Inhibition of cell wall synthesis
- Inhibition of protein synthesis
- Disruption of cytoplasmic membrane
- Inhibition of general metabolic pathway
- Inhibition of DNA or RNA synthesis
- Inhibition of pathogen’s attachment to, or recognition of, host
What antimicrobial mechanism of action blocks peptide and sugar analogs of attachment or receptor proteins, especially viruses?
Inhibition of pathogen’s attachment to, or recognition of, host
What antimicrobial mechanism of action uses pathways not used by humans?
Inhibition of general metabolic pathway
What antimicrobial mechanism of action uses analogs– incorporated into DNA/RNA of pathogens, distort nucleic acids, prevent further processing?
Inhibition of DNA or RNA synthesis
What antimicrobial mechanism of action dirupts translation to target and target differences b/w prok/euk ribosomes?
Inhibition of protein synthesis
What antimicrobial mechanism of action is selectively toxic to fungal or bacterial cells which have cell walls?
Inhibition of cell wall synthesis
What antimicrobial mechanism of action often forms a channel through membrane, damaging its integrity?
Disruption of cytoplasmic membrane
Elaborate on the ribosomes that prokaryotes contain and eukaryotes contain?
prokaryotes–> 70S
Eukaryotes–> 80S, but have 70S in mitochondria
Why could drugs that target the prokaryotic 70S ribosomes be harmful to us?
our mitochondria have 70S ribosomes also
What are examples of drugs that target the 70S ribosome?
- tetracycline, monocycline, doxycycline
- azithromycin, erythromycin
RUBBING ALCOHOL in hand sanitizer!!!!!
What is it called when the spectrum of action is effective against a few organisms?
Narrow-spectrum
more important to know what organism is causing the inf.
What is it called when the spectrum of action is effective against many organisms?
Broad-spectrum
What may the use of Broad-Spectrum antimicrobial drugs cause?
kill off normal flora –> reducing microbial antagonism–> allowing for secondary or super-infections to develop
What do we call side effects that are not what was intended?
Unanticipated effects
What do we call side effects that are negative side effects?
adverse reactions
How common are allergies to drugs? How serious are they?
rare, but may be life threatening–> Anaphylactic shock or hypersensitivity
What are the three clinical considerations in prescribing antimicrobial drugs?
- Side effects
- Allergies
- Toxicity
Describe why toxicity is a clinical consideration when prescribing antimicrobial drugs.
- drugs may be toxic, esp. to kidneys, liver, lungs
- needed when prescribing to pregnant women
What are two side effects from toxicity of antimicrobial agents she mentioned?
- “black hairy tongue” from antiprotozoan drug–> metronidazole
- discoloration and damage to tooth enamal caused by tetracycline
Why shouldn’t pregnant women take tetracycline?
binds to Ca++ ions on teeth–> and if taken while developing and exposed to sunlight it oxidizes and causes color change
- found out can cause this in fetus
Why may disruption of normal microbiota need to be taken into consideration when it comes to prescribing antimicrobial drugs?
can cause overgrowth of normal flora–> causing secondary infection (Ex: yeast, C-diff)–> greatest concern for hospitalized patients
T/F. some pathogens are naturally resistant to antimicrobial drugs
true
What are the two ways that some bacteria acquire resistance?
- New mutations of chromosomal genes
2. Acquisition of R-plasmids via Horizontal Gene Transfer
What is is called when a pathogen can acquire resistance to more than one drug? Where is the common?
Multiple Resistance
common when R-plasmids exchanged and in hospitals/nursing homes–> constant use of drugs eliminates sensitive cells–> how get–> “superbugs”
What is it called when resistance to one antimicrobial agent may confer resistance to similar drugs?
Cross Resistance
How can we decrease resistance to antimicrobial drugs?
- Maintain high conc. of drug in patient for sufficient time
- combination of agents–> synergism
- use only when necessary
- develop new variations
- search for new antibiotics
What is it called when one drug enhances effect of second drug?
Synergism
—use of antimicrobial agents in combination
Why is it important to finish out antimicrobial drugs once you start taking them?
kills all sensitive cells and inhibits others so the immune system can destroy them–> if stop taking it, then sensitive ones die, but the strong ones never do–> they can replicated and lead to more antimicrobial resistance
What may be a new research area to search for new antibiotics?
quorum sensing–> bacterial communication chemicals/ how they communicate
