Shared Flashcard Set

Details

Advanced Pharmacology
Antimicrobial Therapy
45
Medical
Graduate
11/01/2010

Additional Medical Flashcards

 


 

Cards

Term
What are the four mechanisms of action for antimicrobial therapy?
Definition

*Inhibitors of Cell wall sythesis

*Inhibitors of protein synthesis

*Inhibitors of DNA synthesis

*Inhibitors of metabolic steps essential for replication- Folic acid synthesis

Term
What chemical structures help classify antibiotics into classes?
Definition

*B-lactam

*Aminoglycosides

*Macrolides

*Fluoroquinilones

*Tetracylines

*Sulfonamides

Term
What five drug groups fall under the classification of B-Lactam antibiotics?
Definition

*Penicillin

*Cephalosporins

*Carbapenems

*Carbacephems

*Monobactams

Term
How do B-Lactam antibiotics work?
Definition
*By inhibiting bacterialcell wall synthesis
Term
What do all B-lactam drugs have in common? What is required for B-lactam drugs to have antibiotic action?
Definition

*A four membered B-lactam ring

*That the B-lactam ring is intact

Term
What classification of drugs have the most troublesome and most frequent source of allergic reactions among all antibiotics?
Definition
*B-Lactam Antibiotics
Term
What have bacteria developed to become resistant to actions of B-lactam antibiotics?
Definition
*B-Lactamases that hydrolyze the B-lactam ring.
Term
How do B-Lactamases inactivate or destroy B-lactam antibiotics?
Definition
*The B-lactam ring is enzymatically cleaved by bacterial B-lactamases
Term
What are some B-lactamase inhibitors?
Definition

*Clavulanic Acid

*Sulbactam

*Tazobactam

Term
What is another name for B-lactamase inhibitors?  What effects do they have?
Definition

*They have very weak antimicrobial effects

*Called suicide inhibitors because they permanately bind when they inactivate B-lactamases.

Term
What are considered natural penicillins?
Definition

*PCN G

*PCN VK

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
What is 1 unit of PCN?
Definition
*0.6 mcg
Term
What is 1M units for PCN?
Definition
*0.6g
Term
How do PCNs differ?
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
*Penicillins
Term
What are the only antibiotics that are combined with B-lactamases?
Definition
*Penicillins
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 

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

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?
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

Term
What is a prototype of first generation cephalosporins?
Definition
*Cefazolin (Ancef)
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

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
*Ancef
Term
What is a second generation cephalosporin with a wide spectrum of activity than first generation drugs?
Definition
*Cefoxitin (Mefoxin)
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
*Ceftriaxone (Rocephin)
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.

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

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
*Carbapenems
Term
What carbapenem is inactivated by renal dihydropeptidase 1?
Definition
*Imipenem
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

Term
What is a synthetic monobactam that is relatively resistant to B-Lactamases and active against gram rods?
Definition
*Aztreonam
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

Supporting users have an ad free experience!