1/30/17 SMITH Antibiotics 1 TEST #1 Flashcards
What are the two types of antimicrobial classes that target the cell wall synthesis?
- Beta Lactams
- Vancomycin
- Bacitracin
What must the B-lactam drugs bind to, to be effective?
-Transpeptidase enzyme (penicillin-binding protein) on the bacteria’s cytoplasmic membrane
What must B-lactam drugs evade to be effective?
-Bacterial defenses
What must B-lactam drugs pentrate to be effective?
-Outer cell layers to reach inner cytoplasmic membrane
What must B-lactams keep in their structure to be efective?
B-lactam ring structure
What on the B-lactam drugs resembles the D-ala-D-ala end of the peptidie that serves as a substrate for transpeptidase enzymes?
B-lactam region
What are 6 subclasses of B-lactam antimicrobials?
- Natural Penicillins
- Aminopenicillins
- Penicillinase-resistant penicillins
- Anti-Pseudomonal
- Cephalosporins
- Carbapenems: Impinem
What is the ultimate goal of the B-lactam antibiotics?
-Reach the transpeptidase enzyme
What does the binding of the B-lactam drugs to the transpeptidase penicillin binding proteins prevent?
-Transpeptidation (last step in new peptidoglycan (cell wall) synthesis)
Are B-lactam drugs bacterocidal or bacteriostatic?
-Bacterocidal
What do all B-lactam drugs require?
-Active proliferating microorganisms to maximally effective
What are B-lactam drugs inactive against?
-Organisms devoid of peptidoglycans (virus, mycobacteria, and fungi)
What type of drug is a B-lactam drug?
-Type II
What are two examples of Natural Penicillins?
- Penicillin G
- Penicillin V
What are natural penicillins highly active against?
-Gram + organisms
What are natural penicillins very susceptible to?
-Bacterial B-lactamases
What are two examples of Aminopenicillins?
- Ampicillin
- Amoxicillin
What did the aminopenicillins add to the penicillins?
-An amine group
What did the addition of the amino group on the penicllins to create aminopenicillins do for the targets of aminopenicillins?
-Extended spectrum to include the Gram - as well as the Gram +
T/F Aminopenicillins are still susceptible to B-lactamases
-True
What are 4 examples of penicillinase-resistant penicillins (anti-staphylococcal penicillin)?
- Methicillin
- Nafcillin
- Oxacillin
- Dicloxacicillin
What are the Penicillinase resistant penicillins relatively resistant to?
-B-lactamases
What penicillinase resistant penicillins is used as a first line treatment of choice for staphylococcal endocarditis?
-Nafcillin
What are 3 examples of Anti-Pseudomonal penicillins?
- Monobactams (aztreonam)
- Ureidopenicillins (piperacillin)
- Carboxypenicillins (Ticarcillin, indanyl carbenicillum)
What type of bacteria do Anti-Psudomonal penicillins have no activity against?
- Gram +
- Anaerobes
Of all the anti-psudomonal penicillins what two have the broadest spectrums of activity?
- Ticarcillin
- Peperacillin
T/F Cephalosporins are built on a 7-aminocephalosporanic acid instead of penicillins traditional 6-aminopenecillinic acid
True
Cephalosporins: Bacteriostatic or Bacteriocidal
Bactericidal
What is the broadest antibacterial available?
-Carbapenems
Of the two natural penicillins what is the only true naturally occurring penicillin?
-Penicillin G
What separates Penicillin G and Penicillin V?
-Penicillin V is acid stable so you can take it orally because the acid won’t chew it up
Are penicillins considered broad or narrow spectrum?
-Narrow
What is Penicillin G rapidly hydrolyzed by?
-Penicillinase enzymes (B-lactamase enzymes)
What is the drug of choice when prolonged low concentrations are required for example syphilis?
-Benzathine penicillin (Durapen)
What is the drug of choice for listeria monocytogenes, prophylaxis of infective endocarditis, or treatment of UTIs caused by susceptible enterococci?
-Aminopenicillins
Which of the aminopenicillins has a higher oral absorption?
-Amoxicillin
What aminopenicillins has a longer half-life and is less likely to cause adverse GI effects?
-Amoxicillins
What gram - strains does aminopenicillins work against?
- H. influenzae
- Enterics
What aminopenicillins dose-dependently inhibits renal tubular excretions of methotrexate that results in prolonged high serum levels of methotrexate?
-Amoxicillin
What is the drug of choice for standard prophylactic prevention of bacterial endocarditis?
-Oral Amoxicillin
What is the alternative drug for prophylactic prevention of bacterial endocarditis if there is a case of non-anaphylactic allergy?
-Cephalexin (cephalosporin)
What are some alternatives in cases of serious allergy requiring non-B-lactams to do a prophylactic prevention of bacterial endocarditis?
- Clindamycin
- Azithromycin
- Clarithromycin
What is the drug of choice in patients unable to take oral medication so long as they are not allergic to penicilin?
-Ampicillin
What is an adverse effect of ampicillin?
-Pseudomembranous coliitis
Which of the aminopenicillins has better absorption orally and is not influenced by food consumption?
-Amoxicillin
What type of aminopenicillin can have different effects depending on food consumption?
-Ampicillin
How is ampicillin primarily delivered?
-IV
If you have Hydrocortisone and ampicillin delivered at the same time in an IV solution what occurs?
-THe Hydrocortisone inactivates the ampicillin
What are Penicillinase-resistant penicillins (Anti staphylococcal penicillins) active against?
- Staphylococci
- Streptococci
T/F The Penicillinase-resistant penicillin (Methicillin, nafcillin, oxacillin, and dicloxacillin) are less potent than Pen G
True
What is the drug of choice for serious S. aureus infetcions (non-MRSA)?
-Nafcillin (use Naf for Staph)
How are most B-lactams excreted?
-Renally
If you give a B-lactam drug with probenecid (uric acid reducer to treat gout) what happens to the serum levels and half-lives?
- Increased
- Prolonged
What B-lactam drugs do not interact with probenecid?
-Nafcillin
-Oxacillin
-Dicloxacillin
(these undergo biliary excretion)
How do you administer Anti-psudomonal penicillins?
IM or IV
What is one of the few antibiotics capable of treating Stenotrophomonas maltophilia infections on mechanical devices such as for ventilation or urinary catheters?
-Ticarcillin (Anti-pseudomonal penicillins)
What type of Anti-pseudomonal penicillin has the broadest spectrum?
-Piperacillin
What is a great drug of choice for patients that have IgE-mediated penicillin allergies?
-Aztreonam (Monobactams) (Anti-pseudomonal penicillins)
What are some common side effects of Penicillins?
- Hypersensitivity (anaphylactic reaction)
- Confusion
- Lethargy
- Twitching
- Seizures
- Kidney failure
- Coma
T/F 10% of people are allergic to penicillins and these people are usually cross sensitive to all other B-lactams including cephalosporins
True
What are 4 B-lactam drugs that are broad spectrum that could lead to superinfections?
- Aminopenicillins (ampicillin)
- Piperacillin
- Cephalosporins
- Aztreonam
What is the most important drug from the first generation cephalosporins?
-Cefazolin
What first generation cephalosporin is used for prophylaxis prior to surgery?
-Cefazolin
What are three 2nd generation cephalosporins?
- Cefaclor
- Cefoxitin
- Cefuroxime
What 2nd gen cephalosporin drug is used to treat oral sinusitis and otitis caused by H.influenzae?
-Cefaclor
What 2nd gen cephalosporin has enhanced anaerobe activity and extended B-lactamse resistance?
-Cefoxitin
What 2nd Gen cephalosporin is unique since it can cross the blood brain barrier?
-Cefuroxime
What generation has the broadest spectrum of all the cephalosporins and are extremely effective against Gram - organisms?
-3rd generation
What are three 3rd generation cephalosporin drugs?
- Cefotaxime or ceftriaxone
- Ceftazidime
- Cefdinir
What is unique about the 3rd gen cephalosporin drugs?
- Activity against gram - rods
- Most can cross the Blood Brain Barrier
What 3rd gen cephalosporin drug is used to treat Pseudomonas aeruginosa?
-Ceftazidime
What is an example of a 4th generation cephalosporins?
-Cefepime
What is an example of a 5th generation cephalosporin?
-Ceftaroline
What cephalosporin has activity greater that ceftazidime against streptococci and methicillin-susceptible staph?
-Cefepime (4th generation)
What cephalospring is active against MRSA?
-Ceftaroline (5th generation)
What drug is the broadest spectrum coverage available to man?
-Imipenem
What type of drug is very stable in the presence of B-lactamases, including penicillinase and cephalorsporinase that are resistant to most B-lactam antibiotics?
-Carbapenems:Imipenem
What are four Non-B-lactam antibacterials that are also cell wall inhibitors/disrupters?
- Bacitracin (topical)
- Vancomycin (IV)
- Polymyxins
- Daptomycin (IV)
What does vancomycin inhibit cell wall synthesis in?
-Gram + bacteria at an earlier stage that B-lactams
What drug do you use to treat endocarditis in penicillin allergic patients?
-Vancomycin
What are the three types of allergic reactions to penicillins/B-lactams?
- Immediate/acute onset
- Accelerated onset
- Delayed onset
If a patient was given Penicillin VK less that 15 minutes ago and develops laryngeal edema, urticaria, severe hypotension, GU disturbance, bronchoconstriction and shock what does the patient have going on?
-Anaphylactic reaction
What are Polymyxins bactericidal against?
-Gram - bacteria
What are Daptomycin bactericidal against?
-Gram + bacteria
What is the 1st line IV treatment for complicated skin infections, bloodstream infections, endocarditis, bone and joint infections, and meningitis cause by MRSA?
-Vancomycin
T/F
Vancomycin should be used to treat methicillin-sensitive S. aureus because it is superior to nafcillin
False
-Vancomycin is inferior to nafcillin and shouldn’t be used
T/F
Vancomycin has traditionally been considered a nephrotoxic and ototoxic drug.
True
What type of bacteria does Bacitracin disrupt?
-Gram + and Gram -
Bacitracin is Bactericidal or bacteriostatic?
-Bactericidal
Vancomycin is Bactericidal or bacteriostatic?
-Bactericidal
What type of bacteria does Vancomycin disrupt?
-Gram + but not gram -
T/F Daptomycin is a cyclic lipopeptide
True
What drug causes Red Man Syndrome as an adverse effect?
-Vancomycin
What drug is active against MRSA and Vancomycin resistant Enterococcus?
-Daptomycin
What drug can cause myopathy, arthalgia, and eosinophylic pneumonia as adverse effects?
-Daptomycin
