Term
| What grp of Rxs are cell wall inhibitors? |
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Definition
Beta-Lactams (penicillins, cephalosporins, carbapenems, monobactams)
Vancomycin
Daptomycin
Bacitracin |
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Term
| What Rxs have the beta-lactam ring? |
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Definition
| Penicillin, cephalosporins, carbapenems |
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Term
| How does the resistance develop against beta-lactam antiboitics? |
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Definition
| There is mutation at the active site of the PBP (transpeptidase) thus no more covalent binding |
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Term
| What is the second way that penicillin helps the cell wall lose its integrity? |
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Definition
| It doesn’t inhibit autolysin which is produced by the bacteria to remodel its cell wall |
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Term
| How do antibiotics enter the gm –ves? |
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Definition
| Via the porins- channels that permits transmembrane entry |
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Term
| Which penicillins are susceptible to beta-lactamases? |
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Definition
| Penicillin G (given IV as its Gastric sensitive); Ampicillin & Amoxicillin, thus used w/ clavulanic acid & sulbactam, which are beta-lactamase inhibitors |
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Term
| Comment on the potency of Penicillin G & V? |
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Definition
| V is less potent and thus needs a higher MBC |
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Term
| Which penicillins are beta-lactamase resistant? |
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Definition
| Methicillin, Nafcillin (excreted in bile), Oxacillin, Dicloxacillin (=> used to Tx Staph that produce beta-lactamase) |
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Term
| Which penicillins make up the extended-spectrum? |
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Definition
| Ampicillin (Tx Listeria monocytogenes) & Amoxicillin (=> similar to Penicillin G; more effective against gm –ve bacilli; used to Tx RTI but resistance is a big prob) |
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Term
| What are the Antipseudomonal penicillins? |
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Definition
| Carbenicillin, Ticarcillin, Piperacillin (most potent). Are used to Tx P. Aeruginosa and many other gm –ve bacilli |
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Term
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Definition
Oral: Penicillin V, Amoxicillin (not impaired by food) + clavulanic acid/ ampicillin, Carbenicillin (indanyl ester), dicloxacillin
IV or IM only: Ticarcillin, Carbenicillin, Piperacillin, ampicillin + sulbactam, piperacillin + tazobactam
IM Repository release: Procaine Penicillin G & Benzathine Penicillin G |
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Term
| How is penicillin excreted? |
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Definition
| 10% GF & 90% tubular secretion, also lost in milk and T ½ is 30min – 1 hr |
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Term
| What is the antigenic determinant for penicillin? |
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Definition
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