Antibacterial Agents

Home

Get App

Create

What is the MOA of beta-lactams?
- bactericidal
- Penicillin-binding proteins (PBP) make up the cell
- bind to (PBP)
- inhibit cell wall synthesis
What is penicillinase-resistant penicillins?

have substitutions to the beta-lactam ring that sterically inhibit penicillinase
Which Penicillins are given IV?
- Pen G
- Nafcillin
- Oxacillin
- Ampicillin (also oral)
- Ticarcillin
- Piperacillin
- Unasyn (Amp/sulbactam)
- Timentin (Ticarcillin/clavulanate)
- Zosyn (Pip/tazobactam)
Which Penicillins are given PO?
- Pen VK
- Dicloxacillin
- Amoxicillin
- Ampicillin (IV also)
- Carbenicillin (only used for UTIs)
- Augmentin (Amox/clavulanate)
Which Penicillins are given IM?
- benzathine Pen G
- procaine Pen G
- Pen G benzathing + Pen G procaine
What are the natural penicillins?
- Pen G (and all variations)
- Pen VK (Veetids)
What are the spectrum of activity for natural PCNs?
- Streptococcus pyogenes
- Streptococcus pneumoniae
- Streptococcus viridans
- Clostridium perfringes (gas gangrene)
Why are natural PCNs are ineffective against staphylococcus aureus?

because they are readily hydrolyzed by penicillinases (Beta-lactamases) to become resistant to penicillin
Which natural PCN are more active toward Gram-negative organisms?

Pen G is 5-10x more active than Pen V
What are the penicillinase-resistant penicillins or antistaphylococcal penicillins?
- methicillin
- nafcillin
- oxacillin
- dicloxacillin
What are the spectrum of activity for penicillinase-resistant penicillins/antistaphylococcal penicillins?
- MSSA
- streptococci (but not enterococci)
What are the extended-spectrum aminopenicillins?
- ampicillin
- amoxicillin (Trimox, Amoxil)
What are the extended-spectrum antipseudomonal penicillins?
- carbenicillin
- ticarcillin
- piperacillin
What are the beta-lactamase inhibitors?
- clavulanic acid
- sulbactam
- tazobactam
What are the beta-lactam/beta-lactamase inhibitor combinations?
- Augmentin (amoxicillin clavulanate)
- Unasyn (ampicillin sulbactam)
- Timentin (ticarcillin clavulanate)
- Zosyn (piperacillin tazobactam)
What are the main coverage of Augmentin & Timentin?
- H. flu
- Moraxella catarrhalis
- Klebsiella pneumonia
- MSSA
- Anaerobes
How are beta-lactam/beta-lactamase inhibitors formulated?
- amount of beta-lactam changes as dose increases
- amount of beta-lactamase is constant
- 2x250 does not equal 1x500, the inhibitor concentration would be too high = more SE
How are Penicillins eliminated?
- renally: glomerular filtration and active tubular secretion
- Oxacillin (renal and bile)
- Nafcillin (bile)
What type of killing do Penicillins posess?

time-dependent killing
What are the SE of Penicillins?
- NVD (infectious and non-infectious D)
- hypersensitivity
- anemia
- decreased platelets
- increased INR
- acute interstitial nephritis (methicillin, nafcillin)
- excess sodium load (ticarcillin worst)
- excess potassium load (Pen G)
- superinfection
What pregnancy class are Penicillins?
- class B
- DOC in pregnancy
What are the DI of Penicillins?
- oral contraceptives (use condoms for 1 wk after antibiotics)
- warfarin (increased INR d/t loss of gut flora)
What is the MOA of cephalosporins?
- bactericidal
- inhibition of mucopeptide synthesis in bacterial cell wall
- cause cell wall lysis
How are cephalosporins dosed?
- IV
- PO
- IM
How are cephalosporins grouped?

grouped into generations based on their antimicrobial coverage
What cephalosporins are 1st generation?
- cefazolin (Ancef)
- cephalexin (Keflex)
- cefadroxil (Duricef)
Which 1st generation cephalosporins are given PO?
- cephalexin (Keflex)
- cefadroxil (Duricef)
What are the groups of microorganisms that 1st generation cephalosporins cover?

Gram (+) more than Gram (-)
What cephalosporins are 2nd generation?
- cefoxitin (Mefoxin)
- cefuroxime (Zinacef)
- cefotetan (Cefotan)
- cefaclor (Ceclor)
- cefprozil (Cefzil)
Which 2nd generation cephalosporins are dosed PO?
- cefaclor (Ceclor)
- cefprozil (Cefzil)
Which 2nd generation cephalosporins are dosed both IV & IM?
- cefuroxime (Zinacef)
- cefotetan (Cefotan)
What cephalosporins are 3rd generation?
- cefdinir (Omnicef)
- ceftriazone (Rocephin)
- ceftazidime (Fortaz)
- cefotaxime (Claforan)
Which 3rd generation cephalosporins are dosed PO?

cefdinir (Omnicef)
Which 3rd generation cephalosporins are dosed IV & IM?
- ceftriazone (Rocephin)
- ceftazidime (Fortaz)
What cephalosporins are 4th generation?
- cefepime (Maxipime)
- IV & IM
What cephalosporins are 5th generation?
- ceftaroline (Teflaro)
- IV only
What kind of killing does cephalosporins possess?
- time-dependent killing
- above the MIC
Which cephalosporins are good for anaerobes?
- cefoxitin (Mefoxin)
- cefotetan (Cefotan)
Which cephalosporins are good for pseudomonas?
- ceftazidime (Fortaz)
- cefepime (Maxipime)
Which cephalosporins are good for MRSA, MRSE, and enterococcus?

ceftaroline (Teflaro)
Which cephalosporin is best for use in neonates?

cefotaxime (Claforan)
How are cephalosporins eliminated?
- mostly renal: glomerular filtration and active tubular secretion
- ceftriaxone (bile 30-40%)
Which cephs can penetrate the CNS?
- cefuroxime (2nd-gen)
- cefotaxime (3rd-gen)
- ceftriaxone (3rd-gen)
- ceftazidime (3rd-gen)
How protein bound are cephs?

ceftriaxone is concentration dependent: increasing dose increases fraction unbound, so higher doses and longer interval is better
What are the SE of cephs?
- hypersensitivity
- increased INR/bleeding/hypoprothrombinemia in cephs that have MTT side-chain (cefotetan)
- NVD
- HA
- dizziness
- neurotoxicity (high dose in renal impaired)
- bilirubin encephalopathy (ceftriaxone - highly PPB)
Which ceph should not be used in neonates?

ceftriaxone displaces bilirubin
What are the DI of cephs?

do not administer ceftriaxone with calcium-containing IV fluids in neonates (increased risk of precipitation)
How can bacteria becomes immune or resistance to cephalosporins?

through the production of beta-lactamases

Author

skylinezts

102628

Card Set

Antibacterial Agents

Description

Antibacterial Agents

Updated

2011-09-19T06:08:18Z

Show Answers