Term
| Penicilllin G Potassium (Pfizerpen) |
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Definition
Natural penicillin
Mechanism: Bactericidal; Inhibits final stage (cross-linking) of bacterial cell wall synthesis by binding to specific penicillin-binding proteins (PBPs) located inside the cell wall; penicillin nucleus is the chief structural requirement for the bio activity
Resistance mechanisms: inactivation by bacterial b-lactamase; decrease permeability; alterting PBPs; Lack of cell wall (chlamydia has a cell wall but ISN'T peptidoglycan based)
PHK: Never give intrathecal (cause seizures); + procain for sustained effect; poor BBB penetration
Excretion: Probenecid (gout med) will partially block excretion
Natural penicillin rules: most rapidly excreted drug in kideny
- highest antibacterial activity against certain gram positive bacteria
- some gram negative coverage
- some anaerobic coverage
- readily inactivated by B-lactamase (penicillinase)
- no antipseudomonal activity
- eliminated by active transport in the kidney
- poor CNS penetration (except inflam.)
- Penicillin V acid resistant
Bacterial spectrum: Streptococcus pneumoniae (Diplococcus), Neisseria gonorrhoeae, Neisseria meningitidis, Streptococcus pyogenes, Staphylococcus, Bacillus anthracis, Treponema pallidum, Clostridia; most strains of Corynebacterium diphtheriae, Listeria, all strains of Bacteroides except B. fragilis, Actinomyces species, Pasteurella multocida.
Most strains of Leptospira are moderately susceptible to Penicillin G.
Penicillin G is not effective against amoebae, plasmodia, rickettsiae, fungi and virus.
Other Drugs: Penicillin V
Penicillin G procaine
Penicillin G benzathine (Bicillin) - longest preparation |
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Term
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Definition
Penicillinase Resistant Penicillin/Anti-staph penicillins
Penicillinase Resistant Penicillin (Antistaphylococcal Penicillins)
DOC for penicillinase producing S. aureus
rules:
- lower activity against certain gram-positive bacteria
- resistant to penicillinase
- some gram negative and anaerob coverage
- some are acid stable and highly protein bound.
- drugs of choice against penicillinase producing Staphylococcus aureus.
- more than 20% of S. aureus isolates are resistant (MRSA)!
- hepatic metabolism and renal excretion
Bacterial spectrum: Streptococcus pneumoniae (Diplococcus), Neisseria gonorrhoeae, Neisseria meningitidis, Streptococcus pyogenes, Staphylococcus, Bacillus anthracis, Treponema pallidum, Clostridia; most strains of Corynebacterium diphtheriae, Listeria, all strains of Bacteroides except B. fragilis, Actinomyces species, Pasteurella multocida.
Most strains of Leptospira are moderately susceptible to Penicillin G.
Penicillin G is not effective against amoebae, plasmodia, rickettsiae, fungi and virus.
Other Drugs: Oxacillin
Dicloxacillin
Methicillin |
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Term
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Definition
Extended spectrum penecillins (amino penicillins)
- lower gram pos. coverage
- extended gram negative coverage (E. coli, Salmonella, Shigella, H. influenzae, Proteus).
- Anaerobic coverage when combined with penicillinase inhibitors
- no antipseudomonal activity
- resistance develops frequently
- susceptible to B-lactamase
- acid resistant
- urinary excretion
Bacterial spectrum: Streptococcus pneumoniae (Diplococcus), Neisseria gonorrhoeae, Neisseria meningitidis, Streptococcus pyogenes, Staphylococcus, Bacillus anthracis, Treponema pallidum, Clostridia; most strains of Corynebacterium diphtheriae, Listeria, all strains of Bacteroides except B. fragilis, Actinomyces species, Pasteurella multocida.
Most strains of Leptospira are moderately susceptible to Penicillin G.
Penicillin G is not effective against amoebae, plasmodia, rickettsiae, fungi and virus.
Other Drugs: Ampicillin
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Term
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Definition
Antipseudomonal penecillins
- spectrum: bacteria covered by the extended spectrum penicillins plus some additional enteric gram negative bacilli (Proteus, Enterobacter, Providencia and Serratia species).
- major use: Pseudomonas aeruginosa and Acinetobacter).
- susceptible to B–lactamase (combined with penicillinase inhibitors)
- acid sensitive
- renal excretion
Bacterial spectrum: Streptococcus pneumoniae (Diplococcus), Neisseria gonorrhoeae, Neisseria meningitidis, Streptococcus pyogenes, Staphylococcus, Bacillus anthracis, Treponema pallidum, Clostridia; most strains of Corynebacterium diphtheriae, Listeria, all strains of Bacteroides except B. fragilis, Actinomyces species, Pasteurella multocida.
Most strains of Leptospira are moderately susceptible to Penicillin G.
Penicillin G is not effective against amoebae, plasmodia, rickettsiae, fungi and virus.
Other Drugs: Ticarcillin (Ticar) |
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Term
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Definition
Monobactam
Use: active against gram negative rods (including pseudomonas and serratia); no cross sensitivity with penicillin derivatives
Bacterial spectrum: gram - rods (+pseudomonas and serratia); no gram + or anaerobes
Safe in pts with penicillin allergy |
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Term
| Imipenem, Cilastatin (Primaxin) |
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Definition
Carbapenem
Must be given with cilastatin because it is rapidly inactivated by renal tubule dehydropeptidases
Tox: can cause seizures
Other drugs:
Meropenem (Merrem®)- NOT inactivated by dehydropeptidases; broad spec including anaerobes, gram+, Gram- rods
Ertapenem (Invanz)
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Term
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Definition
Beta-lactamase inhibitor
Other drugs: Sulbactam
Tazobactam |
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