-
Standard pencillins
- Penicillin G - IV
- Penicillin V - more stable in acid, preferred oral
- Benzathine Pencillin - IM, syphilis and prevent RF
- Pharmacokinetics: Penicillin G - large CSF concentration
- Elimination: Kidney
- Toxicity: hypersensitivity rxn
-
Anti-staphylococcal Penicillins
- Stable to beta-lactamase
- Nafcillin: Not absorbed in GI tract, metabolized in liver
- Dicloxacillin Well absorbed in GI tract
- Use: MSSA
- Adverse rxn: eosinophilia, neutropenia
-
Aminopenicillins
- Increased activity against aerobic gram negative bacilli
- Ampicillin: Can reach high CSF levels
- Amoxicillin: Better oral bioavailability
- Elimination: kidney
- Clinical: Streptococci, enterococci, L monocytogenes
-
Antipsuedamonal penicillins
- Extended spectrum aminopencillins
- Ticarcillin:
- Piperacillin
- IV admin where P Aurigunosum is suspected/confirmed
-
Beta lactamase inhibitors
- Combined with antipsuedomonals
- Contain beta lactam ring that binds beta lactamase, allows other beta lactam to exert effect on bacteria
- Ampicillin/sulbactam
- Amoxicillin/clavulanate
-
Cephalosporins
- Spectrum of aerobic gram negative bacteria increases across generations
- Anti-staph spectrum decreases across generations
- Better against enterobacteriaceae than aminopenicillins
- Adverse Rxn: 10% cross allergenicity with penicillins, avoid in people with IgE mediated penicillin allergy
- First generation: Cefazolin, active against strep, staph, and e. coli, prophylaxis in surgery
- Third generation: Ceftriaxone, cefotaxime; better for enterobacteriaceae, H. Influenzae; reach high CSF concentrations
- Fourth generation: cefepime, no activity against MRSA, enterococci, listeria, B Fragilis
-
Carbapenems
- ImipenemBroadest spectrum of all antibiotics
- Broken down by renal beta-lactamase which causes nephrotoxicity, co-administered with cilastatin
- Better penetration and access in gram negative bacteria
- Resistant to beta lactamases
- Excreted through Kidney
- Increase risk of seizures
-
Monobactams
- Aztreonam
- No activity against gram positive bacteria, only gram negative
- Non-allergenic
-
Glycopeptides
- Vancomycin
- Binds to two alanine residues, sterically hinders peptidoglycan elongation
- Only gram positive bacteria
- Resistance: Change in terminal alanine to lactate
- Not absorbed through GI tract
- Very high doses to reach CSF
- Excreted entirely unchanged in urine - anuria increase half life
- Adverse effects: nephrotoxicity (rare), red neck syndrome caused by rapid infusion
- Use: beta lactam resistant gram positive infections; MRSA, coagulase negative staph, enterococci, pneumococci; serious infections with stpah, enterococci, streptococci in pts intolerant of beta lactams
|
|
