Antibiotics 2 Flashcards
What 2 classes of Abs are cell wall inhibitors?
penicillins and cephalosporins
What are the 2 classes of protein synthesis inhibitors?
tetracyclines and macrolides
What is the 1 class of DNA synthesis inhibitors?
fluoroquinolones
Targeting the synthesis of _____ is one of the most widely effective and least toxic antibiotic strategies
bacterial cell walls
What are cell wall inhibitors only effective against?
actively growing bacteria
How does penicillin inhibit cell wall synthesis?
it inhibits transpeptidase that forms cross links between peptidoglycan chains that are essential for cell wall integrity
- causes osmotic pressure on the cells resulting in cell lysis
What enzyme does gram positive bacteria product to break down the cell wall?
- produces autolysins
Without active cell wall synthesis ____ can damage the cell
autolysins
What are the 2 examples of penicillinase resistant penicillins
- methicillin and cloxacillin
What are the 2 examples of extended spectrum penicillins
- ampicillin and amoxicillin
Are penicillins bactericidal or bacteriostatic?
Bacteriocidal
Penicillin V and Amoxicillin are only available as ______
oral preparations
Pipercillin must be through the _____ route
IV/IM
Why do penicillins affect the composition of the intestinal flora?
- because they are incompletely absorbed
Absorption of penicillinase resistant antibiotics are ___ by food in the stomach and must be administered ______
reduced
- before a meal or 2-3 hours after
Does penicillin cross the placenta? What abut the bone or CNS?
- does cross the placenta
- does not penetrate the bone or CNS
Where is penicillin excreted?
- in the urine and breast milk
What are the most common adverse effects of penicillins?
- GI effects relatively common but are seldom severe due to the disruption of normal intestinal microflora
- allergy to its metabolite penicilloic acid relatively common (rash, swelling, anaphylaxis)
- cross allergy within the penicillin class
- no negative birth effects
_____ is a concern in patients receiving anticoagulants also also on penicillin
Reduced coagulation
What are the 4 antibiotics that fall under the class of cephalosporins?
cephalxin, cephalothin, cepazolin, cefepime
Which cephalosporins are the only 2 Abs administered orally?
- cephalexin and cefixime
____ penetrates the bone
cefazolin
____ crosses the BBB
cefuroxime
____ and _____ penetrate the cerebrospinal fluid
cefotaxime and ceftriaxone