2/7/17 SMITH Antimicrobial III TEST #2 Flashcards
What does chloramphenicol inhibit?
-50 S peptidyltransferase
In the broad spectrum of Chloramphenicol is it bacteriostatic or bacteriocidal?
-Bacteriostatic except H. influenze (bacterocidal)
What drug is restricted to life threatening infections of H. influenzae, bacteriodes, Rickettsia (spotted and typhoid fever) and miningitis?
-Chloramphenicol
If you have serious infections where penicillin can’t be used due to allergy that involves meningitis what drug would you use?
-Chloramphenicol
T/F Chloramphenicol can cross the Blood brain barrier?
-True
What drug has adverse effects of hemolytic anemia, aplastic anemia (fatal) teratogenic, and causes Gray Baby Syndrome in premature infants?
-Chloramphenicol
T/F Clindamycin (lincosamides) are antagonistic if co-administered with macrolides
True
What is the spectrum of clindamycin?
-Infections caused by anaerobic bacteria and non-enterococcal Gram + cocci
Does clindamycin have gram - activity?
-No
Is clindamycin bacteriostatic or bacteriocidal?
-Bacteriostatic
What is an adverse effect of clindamycin?
-Psudomembranous colitis (C. difficile)
What are the clinical uses for clindamycin?
- Bone and joint infections
- Anaerboes above the diaphragm
- Gram + microbes
If someone is pregnant should you give them chloramphenicol?
-No
For patients with anaerobic aspiration pneumonia what my be prescribed orally for months as an outpatient therapy?
-Clindamycin
What is the mechanism of Linezolid?
-Binds to 50 S subunit to prevent formation of ribosomal complex
What is Linezolid bactericidal against?
-Streptococci
What is Linezolid bacteriostatic against?
- Enterococci
- Staphylcocci
If you are treating someone with vancomycin-resistant E. faecium what should you use?
-Linezolid
What can you treat Psudomembranous colitis with?
- Vancomycin
- Metronidazole
If you have nosocomial pneumonia (both meth-susceptible and MRSA) what drug should you use to treat?
-Linezolid
If you have community acquired pneumonia (S. pneumonia) and complicated skin infections caused by Strep. Staph, and MRSA what protein synthesis drug should you use?
-Linezolid
What are the three main side effects of linezolid?
- Bone marrow suppression
- Reversible neurotoxicity
- Serotonin syndrome
What is the mechanism of action of Quinuprostin/Dalfopristin (streptogramins)?
-Bind to 50 S subunit
Is streptogramins bacteriocidal or bacteriostatic?
-Bacteriostatic
What drug is reserved for serious infections by multi-drug resistant gram + organisms such as a bacteremia with VRE, enterococcus faecium, and complicated skin infections caused by MRSA?
-Auinuprostin/Dalfopristin (streptogramins)
What is the mechanism of Mupirocin (Bactroban)?
-Reversibly inhibit isoleucyl transfer RNA synthetase enzyme which inhibits protein transaction
What is the only t-RNA synthetase inhibitor?
-Mupirocin (Bactroban)
How is Mupirocin applied?
-Topically, but only small areas at a time
T/F Mupirocin is useful against methicillin-resistant staph aureus (MRSA and meth -resistant S. pyogenes skin lesions
True
What two topoisomerases are necessary for bacterial DNA replication to occur properly?
- Topoisomerase II
- Topoisomerase IV
T/F In prokaryotes Transcription and translation are coupled
True
What in DNA replication affects the degree of supercoiling of the bacterial chromosome?
-DNA Gyrase
What in DNA replication unwinds DNA and breaks hydrogen bonds between base pairs?
-Helicase
What DNA polymerase attaches nucleotides in a 5’ to 3’ direction?
-DNA pol III
What type of DNA polymerase removes RNA primers and forms Okasaki fragments?
-DNA pol I
What in DNA replication facilitates bacterial cell division by unlinking DNA following DNA replication?
-Topoisomerase IV
What is another name for DNA gyrase?
-Topoisomerase II
Which enzymes are the target of fluoroquinolones?
- DNA gyrase (Topo II)
- TOPO IV
Quinolones/fluoroquinolones are bactericidal or bacteriostatic?
-Bactericidal
Are quinolones/fluoroquinolones broad or narrow spectrum?
-Broad-spectrum
What is a 2nd generation of quinolones/fluoroquinolones?
-Ciprofloxacin
On gram + microbes what is the primary target for quinolones?
-TOPO IV
On gram - microbes what is the primary target for quinolones?
-DNA gyrase
The first generation of quinolones only effects what gram type of bacteria?
-Gram -
What is the drug of choice for prophylaxis treatment of Anthrax?
-Ciprofloxacin
What is the best quinolone for treating psudomonas?
-Ciprofloxacin
What is a great drug choice for treating traveller’s diarrhea?
-Ciprofloxacin
If you uncomplicated UTI’s what drug is typically used?
-Ciprofloxacin
What is a 3rd generation quinolone?
- Levofloxacin
- Oxfloxacin
What is a 4th generation quinolone?
-Moxifloxacin
What is the best respiratory flouroquinolone?
-Moxifloxacin
What is a good alternative for Strep pneumoniae or H. influenzae for respiratory infections when resistant to beta-lactams?
-Levofloxacin
What is the only 3rd generation quinolone that can penetrate the CNS?
-Oxfloxacin
T/F Moxifloxacin has great activity against Pseudomonas aeruginosa activity
False
-Poor activity
What type of drug does Al+ and Mg+ antacids or dietary supplements with divalents (Zn++ or Fe++) which will interfere with oral adsorption?
-Fluoroquinolones
What is the most common cause of C. difficile superinfection?
-Ciprofloxacin
If you give ciprofloxacin to a patient with epilepsy what can occur?
-Cause seizures
T/F Ciprofloxacin interferes with the metabolism of theophylline inhalers (asthma) and can produce toxic doses that may provoke seizures
True
T/F Prolongation of the AT interval could be a side effect of Moxifloxacin
true
What are three non-quinolone drugs that disrupt nucleic acid synthesis?
- Metronidazole
- Rifampin
- Nitrofurantoin
What is the mechanism of Metronidazole?
-Inhibit DNA replication
What is the drug of choice for diarrhea due to superinfection with C. difficile (pseudomembranous colitis)?
-Metronidzaloe
What is the drug of choice for tetanus?
-Metronidazole (flagyl)
T/F It is ok to take metronidazole with alcohol
False DO NOT take with alcohol
What is the mechanism of Rifampin?
-Inhibit DNA-dependent bacterial RNA polymerase
What drug must you warn patients that it will turn urine, sweat, and tears a red-orange color?
-Rifampin
What is the mechanisms of action of Nitrofurantoin?
-Highly reactive intermediates that attack bacterial macromolecules
What drug do you use for the treatment of uncomplicated UTIs and prophylaxis against UTIs in people prone to recurrent UTIs?
-Nitrofuranotin
What drug is absorbed from intestine into urine at 90%?
-Nitrofuranotin
T/F Tissue penetration of nitrofurantoin outside urinary tract is negligible
True
