Term
| What are "broad spectrum agents"? |
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Definition
| Abx that is active against many gram + and gram - bacteria. |
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Term
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Definition
| Very ill, focal infections, bacterial infections. |
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Term
| What does "synergism" mean in regards to Abx? |
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Definition
| When the combination is more effective that either agent is alone, more than just additive effects. |
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Term
| What are examples of Abx synergism? |
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Definition
1.One may enhance the penetration of the other: ampicillin + and aminoglycoside for enterococci.The penicillin alters the cell wall allowing the aminoglycoside to penetrate and kill. the bacteria.
2. Extended penicillin plus aminoglycoside against Pseudomonas aeruginosa. |
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Term
| What are the disadvantages of abx combinations? |
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Definition
| Increase toxicity, Increase cost, increase resistance. |
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Term
| What are the Abx to avoid for pregnant women? |
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Definition
| Tetracyclines, quinolones, erythromycin estolates, chloramphenicol, TMP-SMX |
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Term
| What are the Abxs that are safe for pregnant women? |
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Definition
| Most penicillins, cephalosporins, erythromycin base, probably aztreonam |
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Term
| How does category A drug effect pregnancy? |
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Definition
| Controlled studies show no risk. |
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Term
| How does a category B drug effect pregnancy? |
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Definition
| No evidence of risk in humans. |
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Term
| How does a category C drug effect a pregnancy? |
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Definition
| Risk cannot be ruled out. |
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Term
| How does a category D drug effect pregnancy? |
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Definition
| Positive evidence of risk. The drug may be acceptable in life-threatening situations, but data has demonstrated fetal risk. |
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Term
| How does a category X effect pregnancy? |
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Definition
| Contraindicated for pregnancy. |
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Term
| What explains cross-allergies with penicillins? |
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Definition
| The common structural "nucleus". |
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Term
| What is the mechanism for penicillins inactivation? |
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Definition
| Penicillase (beta-lactamase) splits the beta-lactam ring inactivating the antibiotic. |
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Term
| How does the beta-lactamase inhibitor help the parent antibiotic? |
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Definition
| The inhibitor binds to the enzyme irreversibly allowing parent compound to "survive" and be active against the bacteria. |
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Term
| How do beta-lactam Abz work? |
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Definition
| Action-inhibitors of cell wall synthesis. |
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Term
| What is the mechanism of action for beta-lactam drugs (penicillins)? |
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Definition
Inhibit antibiotic bacterial growth by interfering w/ specific step in bacT cell wall synthesis.
1. The Abx interfere w/ final cross-linking steps during synthesis of the rigid peptidoglycan matrix.
2. penicillin binds to penicillin binding proteins (PBPs), promoting lysis of bacT. The PBPs act as initial receptors for beta-lactam abx. |
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Term
| What are the resistance mechanisms to penicillin? |
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Definition
1. Inactivation of abx by beta-lactamase. ex: S. aureus, H. influenza.
2. Alteration in target PBPs. ex penicillin-resistant S. pneumoniae
3. A permeability barrier preventing penetration of abx to target. ex gram - bacT. |
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Term
| How do you administer penicillin? |
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Definition
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Term
| What is the distribution of penicillin? |
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Definition
| modest into CSF, w/ inflammation need high IV dose for meningitis; poor prostate penetration. |
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Term
| What is the renal excretion for penicillin? |
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Definition
| important, so must adjust in renal failure |
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Term
| What are penicillins good for fighting? |
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Definition
| GAS, Viridians strep, oral anaerobes, N. meningitides, Treponema pallidum |
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Term
| What is IV aqueous penicillin G Rx for? |
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Definition
1.high dose: serious infection, meningitis.
2. Intermediate dose: severe strep A cellulites |
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Term
| What is the synergy of IV aqueous penicillin G plus gentamicin Rx for? |
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Definition
| enterococci endocarditis. |
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Term
| What is Benzathine penicillin G plus insoluble salt used to treat? |
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Definition
| Syphilis, GAS pharyngitis, Rhematic fever prophylaxis. Done in an IM shot. |
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Term
| What is the DOC of GAS pharyngitis? |
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Definition
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Term
| What are the side effects of penicillin? |
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Definition
1. Allergic/hypersensitivity: Anaphylaxis rare. Delayed rash most common.
2. Interstitial nephritis/renal failure (rare)
3. Myoclonic twitching/seizures (rare)
4. Drug fever |
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Term
| What are antistaphylococcal penicillins used against? |
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Definition
| S. aureus penicillinase (MSSA), GAS |
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Term
| What are the three antistaphylococcal penicillins? |
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Definition
1. Methicillin
2. Oxacillin
3. Nafcillin |
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