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11 Cards in this Set
- Front
- Back
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Excretion of Penicillins
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Usually in the urine.
Excreted partly in bile - Ampicillin and nafcillin |
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Inhibits tubular secretion of penicillins in urine.
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Probenecid
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Forms of pencillin G administered intramuscularly and have long plasma half-lives.
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Procaine and Benzathine
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MOA of Penicillins
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1) binding to PBP
2) inhibition of transpeptidase 3) activation of autolytic enzymes that cause lesions in bacterial cell wall. |
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Inhibitors of penicillinase
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Clavulanic acid, sulbactam, tazobactam
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Mechanisms of resistance to Penicillins
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1) penicillinse
2) structural changes in target PBP 3) changes in porin structures in the outer membrane |
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Narrow spectrum penicillinase-susceptible agents
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Penicillin G (IV form) - Drug of choice for syphillis.
Resistance - pneumococci, streptococcus pneumoniae, staphylococcus aureus, Neisseria gonorrhea. Penicillin V - used mainly in oropharyngeal infections. Toxicity - hypersensitivity reactions and hemolytic anemia. |
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Very narrow spectrum penicillinase-resistant drugs
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Methicillin, Nafcillin, Oxacillin.
Primary use in treatment of known S. Aureas (except MRSA; reistant b/c of altered penicillin-binding protein target site). Resistance - MRSA, MRSE Toxicity - hypersensitivity reactions; methicillin - interstitial nephritis. |
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Wider spectrum penicillinase-susceptible drugs
Synergestic with aminoglycosides; also used with penicillinase inhibitors. |
Ampicillin and amoxicillin.
Infections resulting from - enterococci, Listeria monocytogenes, E. coli, Proteus mirabilis, Haemophilus influenzae, Moraxella catarrhalis. Toxicity - Hypersensitivity reactions; ampicillin rash; pseudomembranous colitis |
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Wider spectrum penicillinase-susceptible drugs.
(Antipseudomonals) |
Ticarcillin, Carbenicillin, Piperacillin
Use - Pseudomonas spp., Enterobacter, some cases of Klebsiella. Toxicity - Hypersensitivity reactions. |
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Toxicity to Penicillins
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1) Allergy - urticaria, severe pruritus, fever, joint selling, hemolytic anemia, nephritis, and anaphylaxis.
Complete cross-allergenicity b/w different penicillins should be assumed. 2) GI - Nausea and diarrhea. Upsets caused by direct irritation or by overgrowth of gram +. |
