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31 Cards in this Set
- Front
- Back
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What is Chloramphenicol used for?
How is it administered? |
Last resort! Wide spectrum of coverage--aerobic/anaerobic G+/G- microbes.
Available IV ONLY |
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What is the downside to Chloroamphenicol?
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Serious side effects:
--fatal blood dyscrasias --hemolytic anemia --leukopenia --thrombocytopenia --fatal aplastic anemia |
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What is Chloramphenicol an alternate for?
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Alt to:
doxycycline for Rocky Mountain Spotted Fever (Rickettsia) Fluoroquinolones and ceftrixone for Salmonella typhi (typhoid fever) Gentamicin for Yersinia pestis (plague) |
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What is the mechanism of Chloramphenicol?
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Acts same as tetracyclines: inhibits binding of aminoacyl-tRNA to acceptor site
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What is the problem with Chloramphenicol that leads to side effects?
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inhibits MAMMALIAN mitochondrial protein synthesis.
Erythropoietic cells are most sensitive (progenitor cells--not mature RBCs b/c they lack nuclei!) Results in leukopenia, thrombocytopenia, fata aplastic anema. |
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How does hemolytic anemia result from Chloramphenicol use?
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decrease G6PDH
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What causes Gray Baby Syndrome?
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High levels of Chloramphenicol in system due to:
insufficient glucuronyl transferase to conjugate the drug. underdeveloped renal function in the baby. Baby is unable to eliminate the drug. |
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What do increased Chloramphenicol levels cause?
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interference w/ mictochondrial ribosomes which cause:
1. depressed respiration 2. cardiovascular collapse 3. cyanosis (grey pallor) |
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How is Quinupristin/Dalfopristin administered?
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IV for MRSA and vancomycin resistant infections.
Work synergistically |
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What class of drug is Quinupristin/Dalfopristin?
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a streptogramin
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What is the mechanism of Quinupristin?
Dalfopristin? |
Both Quinupristin and Dalfopristin--release peptidyl-tRNA from the DONOR site of peptidyltransferase
In addition, Dalfopristin--inhibits binding of amino acyl-tRNA from the ACCEPTOR site and of peptidyl-tRNA to the donor site of peptidyltransferase. |
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What does Quinupristin/Dalfopristin inhibit?
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CYP3A leads to a decrease in drug metabloism. (be careful when using warfarin and diazepam)
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What are the side effects of Quinupristin/Dalfopristin?
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superinfection --pesudomembranous colitis
Arthalgias/myalgia hyperbilirubinemia |
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What is Linezolid used for and how is it administered?
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use for MRSA and vancomycin resistant infections.
Oral AND IV |
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What are the side effects of Linezolid and what should be done to minimize them?
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colitis, myelosuppression resulting in blood dyscrasias.
Recommend weekly CBC |
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What is the mechanism of Linezolid?
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prevents formation of initiation complex. Inhibition of protein synthesis.
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What kind of toxicity might linezolid cause?
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5-HT toxicity when used with drugs taht enhance 5-HT
--What is 5-HT???-- |
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What are the uses of clindamycin?
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alternative for Bacteroides fragilis, Corynebacterium diptheria
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What is the major side effect of Clindamycin?
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pseudomembranous colitis C difficile
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What is the route of administration for Clindamycin?
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oral, IV, topical for acne, suppository for bacterial vaginosis.
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What is the mechanism for Clindamycin?
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same as that of erythromycin
inhibits the translocation of the aminoacyl tRNA from the acceptor to the donor site. |
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What is Polymixin B effective against?
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G - organisms
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What type of toxicity does Polymixin exhibit?
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nephro and neurotoxic
this is why it is limited to topical use. |
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What is the mechanism of Polymixin B?
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Cidal--cationic detergent. Dissolves membrane.
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What is Polymixin B used for?
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common bacterial infection of the conjunctiva and eyelids
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What are the common combinations of Polymixin B?
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Neosporin= polymixin B + bacitracin + neomycin
Polysporin = bacitracin + polymixin B Polytrim = polymixin B and TMP |
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How many times should Spectinomycin be used?
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EXCLUSIVELY as a single dose IM for Gonorrhea in patients w/ allergy to PCN or for PCN resistant strains of gonorrhea.
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What does Rifacimin treat?
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travelers diarrhea from noninvasive strains of E. coli
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What is Muripocin used for? What is its pitfall?
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ointment and cream.
Alternate for Impetigo from group A Strep or Staph aureus. [first choice is diclocacillin] Pitfall is price |
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What is the mechanism of Muripocin?
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binds bacterial isoleucyl t-RNA synthetase
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What is Nitrofurantoin used for?
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treatment and prevention of UTI.
Use if local E. Coli is >20%. Can color urine brown |
