Term
| What are the five main mechanism of axn for antimicrobials and give examples of each? |
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Definition
Cell wall synthesis inhibitors (penicillins, cephalosporins, vancomycin)
Antimetabolites (sulfonamides)
Affect nucleic acid synthesis (fluoroquinolones, rifamycins)
Protein synthesis inhibitors (aminoglycosides, chloramphenicol, macrolides, clindamycin, tetracyclines)
Disrupt cell walls (polymyin) |
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Term
| What is the difference if any btw broad spectrum & extended spectrum antibacterial Rxs? |
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Definition
| The latter chemically modified Rxs that now are able to target both gram positive and negative microbes BUT both can be used interchangablly |
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Term
| What is postantibiotic effect? |
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Definition
| No one really knows but its when the TC of the Rx is not measurable but the killing effects of it are still present. The two proposed theories are: lag effect of the bacteria to grow back or tight binding of the Rx to the targets |
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Term
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Definition
| One can think of MIC as the mean bacteriostatic conc as its just the conc to inhibit growth in broth but is culture positive - whereas MBC (mean bactericidal conc) is the culture negative |
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Term
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Definition
| Immediate therapy just based on where the site of infection is and pts Hx (hospital or community acquired) and most likely result in administration of broad spectrum therapy |
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Term
| Combination therapy is used for synergism, give three mechanisms with examples? |
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Definition
Sequential blockade (Trimethoprim + Sulfamethoxazole)
Block of drug-inactivating enzymes (clavulanic acid + amoxicillin - inhibited/ degraded by beta lactamases)
Enhanced drug uptake (increased permeability to aminoglycosides after beta-lactam (breaks open the walls) Tx) |
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Term
| What might be a possible disadvantage of combination therapy? |
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Definition
| Some Rxs work on multiplying microbes and thus if used with a bacteriostatic Rx then it becomes less effective |
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Term
| What is the definition of resistance? |
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Definition
| If max level of antibiotic tolerated by host does not halt growth |
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Term
| What are the five main criteria to use antimicrobial chemoprophylaxis? |
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Definition
| It should target a specific pathogen that has no resistance, the drug should show efficacy and only used at TCs for a limited duration |
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