Miscellaneous Flashcards
What do chloramphenicol target?
IV for aerobic/anaerobic G+/G- microbes
What sort of infections will chloramphenicol be used for?
Serious & fatal blood dycrasias (only seriously resistant infections)
What is the mechanism of chloramphenicol?
Inhibits binding of ammoniacal-tRNA to acceptor site
What is the main problem with using chloramphenicol?
Inhibits human mitochondrial peptidyl-transferase
What cells are most sensitive to chloramphenicol?
Erythropoietic cells (leukopenia, thrombocytopenia, fatal aplastic anemia) Causes a decrease in G6PD which predisposes you to hemolytic anemia
What is gray baby syndrome caused by?
1) insufficient glucuronyl transferase (can’t conjugate)
2) underdeveloped renal function (can’t eliminate)
What does chloramphenicol inhibit?
cytochrome P450
Levels of chloramphenicol increase and interfere with mitochondrial ribosomes resulting in what?
Depressed respiration
CV Collapse
Cyanosis
What do quinupristin/dalfopristin treat?
IV for MRSA and vancomycin-resistant infections
What is the mechanism of quinupristin?
Releases peptidyl-tRNA from donor site
What is the mechanism of Dalfopristin?
Inhibits binding of ammoniacal-tRNA to acceptor site & of peptidyl-tRNA to donor site
Quinupristin/dalfopristin inhibits CYP3A which causes what?
Decreased metabolism of warfarin
What are the side effects of quinupristin/dalfopristin?
Arthralgias/myalgias (30-40%) Superinfection (colitis) Hyperbilirubinemia (25%) Severe venous irritation Vancomycin-resistant E. faecium
What is linezolid?
An oxazolidinone
What is linezolid used for?
Vancomycin resistant E. faecium, MSSA & MRSA, skin infections (static or cidal)
How can linezolid be administered?
Oral and IV
What are the risks of linezolid?
Colitis and thrombocytopenia
Is there a limit to how much you should use linezolid?
Do not use for more than 28 days
What is the mechanism of linezolid?
Inhibits formation of the initiation complex
What does linezolid inhibit and what might that cause?
Inhibits MAO-A which may cause 5HT syndrome if with other Rss that have increased 5HT activity
What happens if you use linezolid chronically?
Reversible optic neuropathy
Irreversible peripheral neuropathy
Lactic acidosis
What is tedizolid?
An oxazolidinone Pro-Rx
How is tedizolid administered and what for?
Oral or IV for ABSSSI, including MRSA
What is the mechanism of tedizolid?
Binds 50S ribosomal subunit resulting in inhibited protein synthesis
What are the side effects of tedizolid?
Nausea, Vomiting, Diarrhea, Headache
What are you at risk for when taking clindamycin?
Pseudomembranous colitis caused by opportunistic C. difficile