Chapter 16: Penicillin-Family Antibiotics
Terms
undefined, object
copy deck
- What does penicillin do biologically?
- Beta-lactam ring inhibits the transpeptidase enzyme, arresting cell wall synthesis --> bacteriacidal.
- How can bacteria defend themselves from the penicillin family - 3 ways?
-
1. Gram (-) bugs can alter their porins preventing penicillin penetration
2. Bacteria can have beta-lactamase enzymes
3. Bacteria can alter the molecular structure of the transpeptidase so the beta-lactam can't bind - Describe the possible manifestations of an anaphylactic reaction to penicillin?
- Bronchospasm, urticaria, anaphylactic shock. Delayed rash is most common.
- List the 5 types of penicillins?
- Penicillin G, aminopenicillins, penicillinase-resistant penicillins, anti-pseudomonal penicillins, and cephalosporins.
- When is Penicillin G currently used?
-
Pneumonia caused by Strep pneumo.
Strep pharyngitis. - Describe the coverage of aminopenicillins?
- Broader than Penicillin G, hitting more gram (-)'s. In particular, E coli and the other enterics. Also effective against the gram (+) enterococcus.
- Which penicillin-family antibiotic is taken orally and used in the outpatient treatment of bronchitis, UTIs, and sinusitis?
- Amoxicillin
- What is the ampicillin-gentamicin combo used for?
- Broad gram (-) coverage.
- Which penicillin-family antibiotics is taken orally and used in the outpatient treatment of bronchitis, UTIs, and sinusitis?
- Amoxicillin
- What are methicillin, nafcillin, and oxacillin?
- Penicillinase-resistant drugs that can kill Staph aureus.
- What type of drugs are cloxacillin and dicloxacillin?
- Penicillinase-resistant penicillins.
- Describe the coverage of anti-pseudomonal penicillins?
- Expanded gram-negative rod coverage, especially against pseudomonas. Also active against anaerobes (Bacteroides) and many gram (+)s.
- What are the "pip and gent" and "ticar and gent" antibx combos used against?
- Pseudomonas.
- Clavulanic acid and sulbactam are what type of antibxs? What's their coverage?
- Beta-Lactamase inhibitors - provide broad coverage against the beta-lactamase producing gram (+)s, gram (-)s, and anaerobes.
- The newer cephalasporins are less effective against...?
- Gram (+)s.
- Which bugs are resistant to all cephalosporins?
- MRSA and the enterococci.
- Cephalothin, cefazolin, cephalexin - what type of antibxs?
- 1st generation cephalosporins.
- Cefamandole, cefuroxime, and cefoxitin - what type of antibxs?
- 2nd generation cephalosporins.
- Ceftriaxone, ceftazidime, ceftibuten - what type of antibxs?
- 3rd generation cephalosporins.
- Name the 4th generation cephalosporin?
- Cefepime.
- When are 1st generation cephalosporins used?
- Alternatives to penicillin for staph and strep infections. Prophylaxis against skin infections before surgery.
- What is a good class of agents for community-acquired bacterial pneumonia with negative sputum? Why?
- 2nd generation cephalosporins (cefuroxime), with good coverage of Strep pneumo and H flu.
- Which antibxs are used for the multi-drug resistant aerobic gram (-) organisms that cause nosocomial pneumonia, meningitis, sepsis, and urinary tract infections?
- 3rd generation cephalosporins
- Which antibx has the best CSF penetration?
- Ceftriaxone.
- Imipenem - what is it?
- A new class of beta-lactam antibx that has the broadest antibacterial activity of them all.
- Which bugs are resistant to Imipenem?
- MRSA, some Pseudomonas, ajd mycoplasma (no cell walls)
- What agent must be given alongside imipenem? why?
- Cilastin - inhibits the digydropeptidase that the normal kidney produces that breaks down imipenem.
- What is Aztreonam? It is a magic bullet for which bugs?
- Monobactam. Effective against gram (-) aerobic bacteria.