Antibiotics Section Flashcards
antimicrobial drug
semisynthetic drugs
antibiotics + synthetic drugs (drugs made in a laboratory)
part lab-made, partly made by microbes (antibiotic)
toxic dosage level
therapeutic dosage level
the minimum dose that will harm the host
the minimum dose that will kill the organism
(if kept like that for a long time)
What is the equation for the chemotherapeutic index?
Is it better if this is larger or smaller? Why?
the largest dose that won’t hurt host/ smallest dose that will kill organism
larger is better since it’s safer.
Is it best to use an antimicrobial drug with a broad or narrow spectrum? Why?
Narrow, since you want to target the pathogen as specifically as possible
If you knew that a patient had an infection with Mycobacterium, what antimicrobial drug would you administer?
isoniazid
When there are a lot of different potential pathogens what type of drug is needed?
Give an example of a common type and what is targeted. (not likely tested on but not impossible) NLTOBNI
broad spectrum
common is TRIPLE ANTIBIOTIC:
bacitracin (good against gram +)
neomycin (good against gram - ; ok against +s)
polymixin B (good against gram -)
What do beta-lactam antibiotics do?
Give examples.
disrupt cell wall synthesis (attach to enzymes that cross-link tetrapeptides in peptidoglycan)
penicillin
cephalosporin
what antibiotics block protein synthesis in bacteria
macrolides and chloramphenicol (block action of peptidyl transferase)
aminoglycosides and tetracyclines (inhibit tRNA binding to mRNA codon)
What antibiotics disrupt the nucleic acid synthesis of bacteria?
rifamycin (disrupts RNA synthesis) binds RNA poly
quinolones (disrupts DNA synthesis) inhibit DNA gyrase/ topoisomerase IV
what do polypeptide antibiotics do?
Give an example
what are they especially effective against?
disrupt the cell membrane (by binding to it and stopping function, resulting in cytoplasm leaking)
polymixins
gram - bacteria
what antibiotic is best for disrupting the cell membrane of gram-positive bacteria
briefly explain the mode of action (m.o.a.)
dapromycin (binds to membranes and causes ion spillage; nonpolar cyclic peptide)
what antimicrobial drug is best suited for the disruption of fatty acid synthesis?
what is it especially good against?
platenmycin
gram + bacteria
antimetabolites
how do they behave
give some examples
antibiotics that MIMIC metabolites in the body
this is done to:
sabotage normal processes & inhibit enzymes (through competitive inhibition)
sulfanimide, p-aminobenzoic acid, and folic acid
What type of antibiotics are used as antifungal drugs
which one(s) disrupt the synthesis of ergosterol? Why is it ineffective against bacteria?
which one(s) disrupt mitosis by stopping spindle fiber creation
which ones(s) inhibit cell wall synthesis (by inhibiting 1,3-beta-D-glucan synthase)
which ones inhibit cell wall synthesis (chitin; planting)
inhibition of nucleic acid synthesis?
some are polyene antibiotics
azoles and allylyamines (bacteria contain hopanoids not sterols)
griseofulvin
echinocandins
polyoxins
5-flourocytosine (analog)
