Sketchy - Cell Wall and Membrane Active Antibiotics - Penicillins Flashcards
How do penicillins work their magic?
They interfere with the transpeptidation reaction of bacterial cell wall synthesis
Penicillin binding proteins do this by removing a terminal alanine in the D-ala-D-ala motif preventing cross-linking.
Penicillins work best against what kind of bacteria in general?
Gram positives ie staph and strep
The cell wall of gram positive organisms is made of:
peptidoglycan with repeating D-alanyl-D-alanine oligopeptides
T/F: Penicillin is bacteriocidal.
True
How is Penicillin V administered?
Orally - Penicillin V is acid stable
What is the dosing for Penicillin V?
4x/day
Why is penicillin V not a great choice?
Frequent dosing;
Poor bioavailability
How is Penicillin G administered?
IV and IM
What is an appropriate treatment for Group A streptococcal pharyngitis?
Penicillin V
What is an appropriate tx for rheumatic fever?
Pen V or G
What is an appropriate treatment for left-sided endocarditis caused by Strep viridans or Strep bovis?
Penicillin G
What is the intrapartum treatment for Strep agalactiae (Group B strep)?
Pencillin G prophylaxis
What gram positive bacillus that grows in chains is treatable with penicillins?
Actinomyces israelii
T/F: Clostridium perfringens can be treated with penicillins.
True
What is an appropriate treatment for Pasturella multocida caused by dog bits?
Penicillins
Ampicillin
Piperacillin
What is the treatment of choice for Syphilis?
single dose of benzathine Penicillin G
Works for primary, secondary and early latent forms of syphilis
What gram negative organism can be treated with Penicillin G and causes meningitis?
Neisseria meningitidis
What is the most common mode of resistance against penicillins?
The production of beta lactamases, such as those made by staph aureus
Penicillins can cause what a Type I hypersensitivity reaction resulting in:
anaphylaxis
Penicillin administration can result in what form of anemia as an adverse effect?
Autoimmune hemolytic anemia
Positive direct Coombs test
What adverse effect can penicillins have on the kidney?
Drug-induced interstitial nephritis
Penicillins have cross-reactivity with what drug class?
Cephalosporins
