Table 1a: Summary of Antibacterial Agents Flashcards
What is the mechanism of action of penicllins?
cell wall synthesis inhibition (stage 3)
Are penicillins bacteriostatic or bactericidal?
bactericidal
Penicillin G and Penicillin V covers what spectrum of bacteria?
Gram + cocci (staph, strep, entero)
Gram - cocci (M. catarrhalis)
Gram + rods
Most anerobes (not Bacteriodes)
What drugs would you consider using on a penicillinase producing MSSA infection?
Penicillinase-resistant class (oxacillin, dicloxacillin, nafcillin)
Beta-lactamase inhibitors (Amox/clav, pip/tazo)
What are the extended spectrum penicillins?
Amoxicillin, ampicillin
Extended spectrum penicllins cover what bacteria?
Gram - rods (H. flu, E. coli, Proteus)
Gram + cocci (but not as well as Pen G/ Pen V)
What Penicillin covers pseudomonas?
Pip/tazo
How are most penicllins excreted?
Renal excretion
What are the adverse reactions to penicillins?
Anaphylaxis (rare)
Rash (common)
Convulsions at very high doses
What is the mechanism of action of cephalosporins?
Cell wall synthesis inhibition (stage 3)
Are cephalosporins bacteriostatic or bactericidal?
bactericidal
What are the 1st generation cephalosporins?
Cephalexin, cephradine, cefazolin
What are the 2nd generation cephalosporins?
Cefaclor, cefuroxime, cefoxitin
What are the 3rd generation cephalosporins?
Cefdinir, cefotaxime, ceftriaxone
What is a 4th generation cephalosporin?
Cefepime
1st generation cephalosporins cover what bacteria?
Gram + cocci, gram - rods
most anaerobes
2nd generation cephalosporins cover what bacteria?
Gram - rods (better than 1st gen coverage of gram - rods)
Most anaerobes
3rd generation cephalosporins cover what bacteria?
Gram - rods, moderate pseudomonas activity
most anaerobes
What gen of cephalosporins has good CNS penetration?
3rd generation
Which generation of cephalosporins has the best gram + cocci coverage
1st>2nd>3rd
Which generation of cephalosporins has the best gram - rod coverage?
3rd>2nd>1st
What cephalosporin covers for N. gonorrheoeae?
ceftriaxone
Which 3rd generation cephalosporin covers pseudomonas?
Ceftazidime
What is the mechanism of action of vancomycin?
Cell wall synthesis inhibition (stage 2)
Is vancomycin bacteriostatic or bactericidal?
bactericidal
Vancomycin covers what bacteria?
Narrow spectrum gram + cocci (MRSA, enterococci)
Anaerobes including C. diff
How are most cephalosporins excreted?
Renal excretion
How is vancomycin excreted?
Renal excretion
What is the mechanism of action for the carbapenems?
Cell wall synthesis inhibition (stage 3)
What type of bacteria would be appropriate to treat with carbapenems?
Multidrug resistant organisms
How are carbapenems excreted?
renal excretion
Are carbapenems bacteriostatic or bactericidal?
Bactericidal
Which drugs are macrolides?
Azithromycin, erythromycin, clarithromycin
Mechanism of action of macrolides?
Protein synthesis inhibition (50S)
Are macrolides bacteriostatic or bactericidal?
Bacteriostatic
Macrolides cover for what bacteria?
Gram + cocci
Gram + rods
Some gram - rods
Atypical bacteria: mycoplasma, chlamydia pneumonia
Macrolides concentrate in what part of the body?
Lungs
pharmacokinetics of azithromycin, erythromycin, and clarithromycin?
azithromycin: biliary
Erythromycin: liver metabolism
Clarithromycin: active metabolite
Which macrolides have a lot of drug drug interactions and why?
Erythromycin and clarithromycin because they are inhibitors of P450 metabolism
What drugs are the tetracylines?
Tetracycline, doxycycline, minocycline
Mechanism of action of tetracyclines?
Protein synthesis inhibition of 30S ribosomes
Tetracyclines bacteriostatic or bactericidal?
bacteriostatic
Tetracyclines cover for what bacteria?
MRSA
atypical: chlamydia, mycoplasma
Broad spectrum gram +/- but resistance is common
contraindications to tetracylcines?
Pregnancy or age <8y.o.
Why are tetracyclines contraindicated in pregnant patients and children <8y.o.
Causes abnormal bone/tooth development
Excretion of tetracycline, doxycycline, minocycline?
tetracycline: renal
Doxy/minocycline: non-renal
Tetracyclines have drug drug interactions with what?
metal cations in stomach such as antacids, iron
Mechanism of action of clindamycin?
Protein synthesis inhibition of 50S ribosomes.
Is clindamycin bacteriostatic or bactericidal?
bacteriostatic
Clindamycin covers for what bacteria?
Gram + cocci, MRSA
Anaerobes, but not C. diff
What are the aminoglycosides?
Tobramycin, gentamycin, neomycin, streptomycin.
Mechanism of action of aminoglycosides?
Protein synthesis inhibition of 30S ribosomes
Are aminoglycosides bacteriostatic or bactericidal?
Bactericidal
Aminoglycosides cover what bacteria?
Gram - aerobes (E. coli, pseudomonas)
Linezolid is what class of antibacterial?
Oxazolidinone
Mechanism of action for Linezolid
Protein synthesis inhibition of 50S ribosomes
Is linezolid bacteriostatic or bactericidal?
Bacteriostatic (except strep, its bactericidal for strep)
Linezolid covers for what organisms?
Excellent gram + coverage (staph, strep, entero, MRSA, anaerobes, rods)
When is use of linezolid acceptable?
Multi drug resistant organisms
What 4 abx are renally exreted?
Penicillins Cephalosporins Vancomycin Aminoglycoside Tetracycline (not doxy or mino)
What are the DCRIMES abx that are non-renal excretion?
Doxycycline Clindamycin Rifampin Isoniazid Metronidazole Erythomycin-like (not azithro) Sulfa