Term
| What are the four mechanisms of action for antimicrobial therapy? |
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Definition
*Inhibitors of Cell wall sythesis
*Inhibitors of protein synthesis
*Inhibitors of DNA synthesis
*Inhibitors of metabolic steps essential for replication- Folic acid synthesis |
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Term
| What chemical structures help classify antibiotics into classes? |
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Definition
*B-lactam
*Aminoglycosides
*Macrolides
*Fluoroquinilones
*Tetracylines
*Sulfonamides |
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Term
| What five drug groups fall under the classification of B-Lactam antibiotics? |
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Definition
*Penicillin
*Cephalosporins
*Carbapenems
*Carbacephems
*Monobactams |
|
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Term
| How do B-Lactam antibiotics work? |
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Definition
| *By inhibiting bacterialcell wall synthesis |
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Term
| What do all B-lactam drugs have in common? What is required for B-lactam drugs to have antibiotic action? |
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Definition
*A four membered B-lactam ring
*That the B-lactam ring is intact |
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Term
| What classification of drugs have the most troublesome and most frequent source of allergic reactions among all antibiotics? |
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Definition
|
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Term
| What have bacteria developed to become resistant to actions of B-lactam antibiotics? |
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Definition
| *B-Lactamases that hydrolyze the B-lactam ring. |
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Term
| How do B-Lactamases inactivate or destroy B-lactam antibiotics? |
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Definition
| *The B-lactam ring is enzymatically cleaved by bacterial B-lactamases |
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Term
| What are some B-lactamase inhibitors? |
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Definition
*Clavulanic Acid
*Sulbactam
*Tazobactam |
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Term
| What is another name for B-lactamase inhibitors? What effects do they have? |
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Definition
*They have very weak antimicrobial effects
*Called suicide inhibitors because they permanately bind when they inactivate B-lactamases. |
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|
Term
| What are considered natural penicillins? |
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Definition
|
|
Term
| What are the three Antistaphylococcal PCNs? |
|
Definition
*Nethicillin
*Nafcillin
*Oxacillin |
|
|
Term
| What are the 5 extended-spectrum PCNS? |
|
Definition
*Ampicillin
*Amoxicillin
*Piperacillin
*Ticarcillin
*Carbenicillin |
|
|
Term
|
Definition
|
|
Term
| What is 1M units for PCN? |
|
Definition
|
|
Term
|
Definition
*They differ greatly among different PCNs and depends on their acid stability and protein binding
*Parenteral absorption is complete and rapid. |
|
|
Term
| What drugs are most sensitive to B-lactamases? |
|
Definition
|
|
Term
| What are the only antibiotics that are combined with B-lactamases? |
|
Definition
|
|
Term
| What are the four antimicrobial agents that have B-lactamase resistant properties? |
|
Definition
*Augmentin- Amoxicillin and Clavulanic acid
*Timentin- Ticarcillin and clavalanic acid
*Unasyn- ampicillin and sulbactam
*Zosyn- piperacillin and tazobactam |
|
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Term
| What components make up Unasyn? What are its special properties? |
|
Definition
*Ampicillin & Sulbactam
*Parenteral only
*Broad spectrum against gram + and gram - aerobes and anaerobes.
*Excreted unchanged in the urine |
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|
Term
| What components make up Zosyn and what are the special properties? |
|
Definition
*Piperacillin & Tazobactam
*IV only, 30 minute infusion, every 6 hours
*Has broadest antibacterial spectrum of the PCNs- Gram + and Gram -.
*Renal elimination
*NOT suitable to treat MRSA- very effective against Pseudomonas. |
|
|
Term
| What S/S are seen with PCN reactions? |
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Definition
| *Hypotension, Bronchospasm, angioedema |
|
|
Term
| What are the properties of cephalosporins? |
|
Definition
*Semisynthetic B-lactam antibiotics similar to PCN chemically in MoA and in toxicity
*More stable than PCN against B-lactamases
*Just like PCNs, the B-lactam ring is the chemical group associated with antibacterial activity.
*Broad spectrum; broader than PCNs
*Highly lipid soluble, excellent tissue penetration
*Good bioavailability in oral and IV
*Urinary excretion is major elimination
*reduce dose in renal pts
*Good safety profiles, low incidence of adverse events
*Classified into generations according to spectrum and stability to B-lactamases |
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|
Term
| What is a prototype of first generation cephalosporins? |
|
Definition
|
|
Term
| What type of bacteria is Ancef good against? |
|
Definition
*Broad spectrum
*Very active against gram + Cocci
*No good against MRSA
*Weaker action against B-Lactamases compared to higher generation cepalosporins |
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|
Term
| What is the half life ancef?? How is it metabolized and excreted? |
|
Definition
*Half life: 1.5-2.5 hours
*Does not undergo metabolism, totally unchanged in the urine |
|
|
Term
| What is the drug of choice for antimicrobial prophylaxis in surgery? |
|
Definition
|
|
Term
| What is a second generation cephalosporin with a wide spectrum of activity than first generation drugs? |
|
Definition
|
|
Term
| What is the dose and half life of Cefoxitin? |
|
Definition
*1-2gms
*Half life: 0.7-1 hour |
|
|
Term
| What is a third generation cephalosporin that can penetrate most tissues of the body including CNS? |
|
Definition
|
|
Term
| What is the half life of ceftriaxone and what does it treat? |
|
Definition
*5.8-8.7 hours
*Treats a wide variety of serious infections called by organisms that are resistant to most other drugs. |
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|
Term
| What is a fourth generation cephalosporin that is the newest and most expensive with a wide spectrum of activity that penetrates most tissues including the CNS? What is its half life? |
|
Definition
*Cefepime (Maxipime)
*2 hours |
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|
Term
| Patients who are allergic to PCN have a 5-10% chance of developing an allergy to ___________. |
|
Definition
| *Cephalosporins like ancef |
|
|
Term
| What is a drug that is used for infections that are resistant to other B-lactam antibiotics? Patients with an allergy to PCN may be allergic to these antibiotics as well. |
|
Definition
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|
Term
| What carbapenem is inactivated by renal dihydropeptidase 1? |
|
Definition
|
|
Term
| What is added to Imipenem to inhibit renal hydrolysis? |
|
Definition
*Cilastatin
*Cilastatin + Imipenem= Primaxin |
|
|
Term
| What are side effects of Imipenem? What is the usual dose? |
|
Definition
*N&V, diarrhea, skin rashes, reactions at infusion sites
*Excessive levels with renal failure may lead to seizures
*Painful on injection, add 3mL of Lido
*0.25-0.5g IV q 6-8hr |
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|
Term
| What is a synthetic monobactam that is relatively resistant to B-Lactamases and active against gram rods? |
|
Definition
|
|
Term
| What type of drugs does Aztreonam resemble? |
|
Definition
*resembles Aminoglycosides
*Dose 1-2gm q 8 hours
*half life 1-2 hours |
|
|
Term
| How do aminoglycosides work? |
|
Definition
| *Inhibits protein synthesis |
|
|
Term
| What is the problem with aminoglycosides? |
|
Definition
*Highly water soluble polar compounds and do not enter cells readily
*Does not undergo significant metabolism- nearly all of IV dose is cleared by kidneys unchanged.
*Absorbed poorly in the GIT |
|
|
Term
| What are the toxic effects of Aminoglycosides? |
|
Definition
*Narrow therapeutic index
*Ototoxicity and nephrotoxicity
*Toxicities more likely when given for >5 days, at higher doses, in the elderly, in renal insufficiency
*Concurrent use of loop diuretics can potentiate nephrotoxicity |
|
|
Term
| What drugs are most toxic to the kidneys? |
|
Definition
*Neomycin
*Tobramycin
*Gentamycin |
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