Ch.20 Antimicrobial Drugs Flashcards
(31 cards)
narrow spectrum antibiotics
is effective against specific families of bacteria.
broad-spectrum antibiotics
refers to antibiotics that act against a wide range of disease-causing bacteria.
superinfection:
overgrowth of normal microbiota that is resistant to antibiotic
bactericidal:
kill microbes directly
Major Action Modes of Antibacterial Drugs
- inhibition of cell wall synthesis:
penicillins
cephalosporins
bacitracin
vancomycin
bacteriostatic:
prevent microbes from growing
Major Action Modes of Antibacterial Drugs
- inhibition of protein synthesis
chloramphenicol
erythromycin
tetracyclines
streptomycin
Major Action Modes of Antibacterial Drugs
- inhibition of nucleic acid replication and transcription
quinolones
rifampin
Major Action Modes of Antibacterial Drugs
- injury to the plasma membrane:
polymyxin B
Major Action Modes of Antibacterial Drugs
- inhibition of essential metabolite synthesis:
sulfanilamide
trimethoprim
The action of microbial drugs:
inhibiting cell wall synthesis of peptidoglycan
Penicillins prevent the synthesis
of peptidoglycan
The action of microbial drugs:
injuring the plasma membrane
Polypeptide antibiotics change
membrane permeability.
Ionophore antibiotics: allow for uncontrolled movement of cations
The action of microbial drugs:
Inhibiting protein synthesis
Target bacterial 70S ribosomes
‒ Chloramphenicol, erythromycin,
streptomycin, tetracycline
Streptomycin
changes shape of the 30 S portion, causing code on mRNA to be read incorrectly
tetracyclines
interfere with the attachment of tRNA to mRNA-ribosome complex
The Action of Antimicrobial Drugs
inhibiting nucleic acid synthesis
interfere with DNA replication and transcription
Rifamycin, quinolones (nalidixic acid) & fluoroquinolones
The Action of Antimicrobial Drugs
inhibiting the synthesis of essential metabolites
anti-metabolites compete with the normal substrate for the enzyme
Modes of Antiviral Drugs
- Entry and fusion inhibitors
- Uncoating, genome integration, and nucleic acid synthesis inhibitors
- Assembly and exit inhibitors
- Interferons
Entry & fusion inhibitor
Block the receptors on the host cell that bind to the virus
‒ Block fusion of the virus and cell
Uncoating, genome integration, and nucleic acid synthesis
inhibitors
Prevent viral uncoating
‒ Inhibit viral DNA integration
into the host genome
‒ Nucleoside analogs inhibit RNA/ DNA synthesis
assembly and exit inhibitors
‒ Protease inhibitors: block the cleavage of inhibitor cleavage of protein precursors
‒ Exit inhibitors: inhibit neuraminidase, an enzyme required for some viruses to bud from the host cell
interferons
Produced by viral-infected cells to inhibit further spread of the
infection
Imiquimod:
promotes interferon production
antiretroviral drug is used to treat
HIV infections
