Antibacterials Flashcards
Which bacteria is Benzyl-penicillin effective against?
Gram +’s
IV use for serious pneumococcal, S. pyogenes and meningococcal infections
Which organisms are Amoxicillin and Ampicillin effective against?
Streptococci and enterococci
What is Co-amoxiclav
Amoxicillin combined with Clavulonic acid
What is Flucloxicillin used to treat and why?
First choice treatment for non-MRSA S. aureus
beta-lactamase resistant
Describe the spectrum of use for Piperacillin
Broad spec., good Gram - cover.
Active against Pseudomonas - other penicillins are not
Effective against anaerobes - useful for treatment of serious intra-abdominal infections
Describe spectrum of use for Carbapenems
Effective against a rang of Gram +’s and -‘s, including anaerobes. Example - Meropenem
Describe efficacy of different generations of Cephalosporins
Efficacy against Gram -‘s increases going from 1st gen. to 3rd gen. (effective against Pseudomonas)
Efficacy against Gram +’s decreases going from 1st gen. to 3rd gen.
Why is cephalosporin use discouraged?
They promote opportunistic C. diff infection
What resistance mech. do many Gram neg’s and hospital S. aureus strains possess?
Beta Lactamases
What classes of antibacterials do ESBL’s give resistance to?
Penicillins and 3rd gen cephalosporins
Which organisms sometimes encode carbapenemases?
Highly res. Gram -‘s
What class of antibacterials do Vancomycin and Teicoplanin belong to?
Glycopeptides
What is the mech. of action of Vancomycin?
Inhibition of peptidoglycan precursor assembly
What organisms are Glycopeptides effective against?
Virtually all Gram +’s.
Describe a resistance mech. that has emerged against Glycopeptides and the bacteria in which it has arisen
Mutation of peptidoglycan precursors
Enterococci: E. faecalis
What class of antibacterials is Gentamicin in?
Aminoglycosides
What is the mech. of action of Aminoglycosides?
Inhibition of protein synthesis by binding to 30s subunit of ribososmes
Spectrum of action of Aminoglycosides
Effective against almost all Grma -‘s
Effective against Staph. species but not Strep
How are Vancomycin and Gentamycin administered?
Why do patients require careful monitoring?
IV admin. Both drugs can be highly toxic to the Kidneys
Erythromycin and Clarithromycin are in what class of antibacterials?
Macrolides
Name a tetracyclin
Doxycyclin
What organisms are Macrolides and Tetracyclines effective against?
Gram positives
Used to treat Legionella and atypical pneumonia
What is the mech. of action of Macrolides and Tetracyclines?
Protein synth inhibition
Outline the use for Linezolid and Daptomycin
Highly effective against Gram +’s
Used to treat serious infections
Particularly effective against MRSA
