Flashcards in Antibiotics Deck (86)
Three desired properties of antibiotics
Broad Range (until + diagnosis)
Able to get to body tissues
Give an three examples of a synergistic antibiotic interaction.
SxT will block sequential steps
Cell Wall/Membrane Inhibitors may allow drug entry
One drug may inhibit detox enzymes
Give three reasons for use of multiple antibiotic drugs
Delaying resistance to long-term use
Three categories of patients that should be prescribed prophylactic antibiotics.
Known contact with a known agent
Before surgery with high likelihood of complications
Special Cases -- ex. predisposed to endocarditis, UTI, immunocompromised
How do new biofilm preventing coatings work?
Implanted devices are coated with a cationic detergent that interacts with the quaternary amine
Over the next several days, hydrolysis occurs and releases dead cells
What is fidaxomicin active against?
Inhibits RNA polymerase
What is Bedaquiline active against?
c Subunit of ATP synthase rotor
Why is amoxicillin rarely prescribed alone?
Heightened resistance to the drug
Three primary types of cell wall inhibitors?
Glycopeptides (Vancomycin, Telavancin)
How do beta-lactams work?
Inhibit transpeptidation and activate autolysins in the cell wall
How do bacteria resist beta lactams?
beta-lactamases, lack of PBPs, autolysin mutations
What drugs are often given with beta lactams?
Beta lactamase inhibitors (Clavulinic acid, aulbactam, tazobactam)
Which penicilins are natural? Why use them?
Pen G, Pen V
Best vs. Gram + bacteria
Which penicillins are expanded spectrum? (i.e. also good against Gram -)
Which Penicillins are beta-lactamase resistant? (3)
Which penicillins are acid resistant?
Three most common penicillin +lactamase inhibitor combos
Augmentin = amoxicillin + Clavulanic acid
Ampicillin + Sulbactam
Zosyn/Tazomed = Piperacilin + Tazobactam
Which beta lactam structure provides some natural resistance to beta-lactamase?
(beta-lactam with one ring)
Three types of beta lactams?
Perks of 3rd and 4th generation cephalosporins?
Work on Gram +/-
Can Cross BBB
Examples of 3rd and 4th gen cephalosporins?
Ceftazidime, Cephotaxime, Caphtriaxone
Two downsides to monobactams
Effective vs G- only
name a monobactam
Pro and con of carbapenems?
Possibly toxic (leads to seizures)
Common problem with beta lactams?
How does bacitracin work?
Blocks the de-phosphorylation of bactoprenol
When would you use bacitracin?
Almost only vs. G+
Side effects of bacitracin
Why is bacitracin so hard to absorb?
Its freakin huge