Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

29 Cards in this Set

  • Front
  • Back
Name the major categories of beta lactam antibiotics.
What is the mechanism of action of all beta-lactam antibiotics?
They bind to and inactivate transpeptidases, which are involved in bacterial cell wall synthesis.
What is the difference between Pen G and V? What is the most adverse effect?
Pen G is given I/V and Pen V is resistant to gastric acid, allowing it to be given orally.
Hypersensitivity reactions, up to 8%.
Which bacteria are potentially suscepptible to Pen G?
Gram positives.
Exceptions-Staph. aureus,) Neisseria, spirochetes and most anerobes
Give a mneumonic aid for bacteria sensitive to Pen. G.
Spirochetes/gram Positives/Anerobes/Neisseria
How does probenicid increase the half life of Pen G?
It blocks active renal secretion of penicillin.
Which penicillins are the semisynthetic(antipStaph) penicillins that are potentially more resistant to B- lactamases?

What is the Jarisch-Herxheimer phenomenon?
Worsening of symptoms(fever, headache, muscle pains) soon after Pen G treatment, due to released pyrogens from killed organisms.
Which Penicillin class can be used to treat Pseudomonas aeruginosa?
Do beta lactamase inhibitors such as clavulanic acid or tazobactam improve penicillin activity against penicillin resistant P. aeruginosa?
No. Beta lactamase inhibitors do not really improve the activity of penicillin against Pseudomonas.
Ampicillin or Amoxicillin can be used to treat which organisms?
HELPS(H. influenzae/Enterococci/E. coli,/Listeria/Proteus/Salmonella
Ampicillin and Gentamicin is the standard treatment for meningitis caused by L. monocytogenes. TRUE/FALSE
What are some potential problems with cephalosporins that contain N- methyl thiotetrazole side chains?
Disulfram like reaction causing hypotension, nausea and vomiting when ingested with etanol and prolonged prothrombin time(PT) with risk of bleeds because of interference with Vit. K activity.
Which cephalosporin antibiotics have the best coverage against P. aeruginosa?
Cefipeme(4th gen) and ceftazidime(3rd gen).
Which cephalosporin is often used for the treatment of community acquired meningitis? WHY?
Ceftriaxome and cefotaxime because it can readily cross the blood brain barrier and covers most strains of Streptococcus pneumoniae and Neisseria meningitiditis(most common causes of adult community acquired meningitis)
What is unique about cefoperazone?
Although no longer available in the US, cefoperazone is unique in that it is 70% eliminated in the bile.
Which cephalosporins are commonly used as prophylaxis for GI surgery. WHY?
Cefoxitin, Cefazolin or cefmetazole because they have activity against anerobes.
Are penicillins and cephalosporins effective against Mycoplasma pneumoniae?
No. They do not have cell walls.
Which beta lactam antibiotic is safe for the treatment of Gram neg organisms, such as pseudomonas in patients with penicillin allergies?
What type of bacteria are susceptible to aztreonam?
Aerobic, Gram-negative bacteria
Why is imipenam, which has the broadest coverage of all the Beta lactam drugs, always given with cilastitan?
Cilastitan is a dehydropeptidase inhibitor that inhibits metabolism of imipenam in the kidney. This prevents nephrotoxicity and increases the urine concentration of intact imipenam allowing for therapy of UTIs.
What is the chief concern of having high plasma levels of imipenam?
CNS toxicity/seizures.
What are the advantages of meropenam over imapenam?
Meropenam does not need to be administered with Cilastitan and causes fewer seizures.
How do bacteria become resistant to B-lactam drugs?
Production of beta lactamases mutations in penicillin binding proteins, or altered porins.
Which drug is the treatment of choice for methicillin resistant S. aureus(MRSA) and what are its major side effects?
Vancomycin. Nephrotoxicity, ototoxicity, thrombophlebitis and diffuse erythema due to histamine release.
How do certain Gram + bacteria become resistant to vancomycin?
By mutation of the terminal D-alanine-D-alanine sequence in in bacterial cell wall to which vancomycin binds. Vancomycin inhibits cell wall synthesis but it is not a B-lactam drug.
What is the mechanism of action of bacitracin?
Prevents dephosphorylation and thus regeneration of a phospholipid carrier needed for cell wall synthesis. Topical agent is too toxic for systemic use.
Cycloserine is a second line agent for tbc. What is its mechanism of action. Does it have side effects?
Analogue of D-alanine that prevents the formation of the D-ananyl-D-alanine dipeptide in cell wall synthesis. CNS toxicity: seizures, acute psychosis and neuropathy.
What is the mechanism of action of fosfomycin which is used for UTIs?
Inhibits enolpyruvate transferase, preventing the formation of N-acetylmuramic(NAM) acid.