Antimicrobials III Flashcards
Quinolone and fluoroquinolones attack…
Topoisomerase II (DNA gyrate) and Topoisomerase IV (front end and back end of transcription)
Rifampin attacks
RNA polymerase
What should you warn Nitrofurantoin patients about?
Red orange pee and sweat
What is a second generation quinolone?
Ciprofloxin (fluoro) -Broad spectrum of gut and UTIs, as well as anti anthrax
What is a third generation quinolone?
Levofloxacin (Even broader spectrum)
What is a fourth generation quinolone?
Moxifloxacin (broad broad spectrum, added ANAEROBES to the killed list)
Topoisomerase II is also known as
DNA gyrase
TOPO II is the primary target on gram ( ) bacteria by quinolone, whereas TOPO IV is the target of gram ( )microbes
negative,
positive
Although as you move through the generations of quinolones you gain a broader spectrum, from negative to more positive, you lose …
Anti-Pseudomonas activity (and gram - activity)
What is best against anthrax?
Ciprofloxacin
What should you worry about with prescribing moxifloxacin?
Longer QT interval, connective tissue problems,
What are some things that are contraindications for quinolones
pregnancy/nursing mothers/children under 18
Myasthenia Gravis
Tendonitis
What drugs do quinolones interact with?
Antacids–decrease absorption
Warfarin, theophylline, caffeine, cyclosporin–Inhibited drug metabolism
Name three non-quinolone drugs that disrupt nucleic acid synthesis
Metronidazole
Rifampin
Nitrofurantoin
What is the mechanism of Metronidazole?
Inhibits DNA replication
What does metronidazole kill?
anaerobes, Trichomonas vaginalis, entamoeba histolytic, C. difficile
What are the adverse effects of metronidazole?
Metallic taste, GI disturbance, CNS issues (depression, vertigo, headache), dark orange urine. CONTRAINDICATED: don’t take with alcohol (instant severe hangover) or during your 1st trimester of pregnancy (FDA category B drug)
How does the extreme hangover take place?
Aldehyde dehydrogenase is disrupted by disulframs, so you get a build up of acetaldehyde (most common with metronidazole, but also B lactase, yada yada)
Rifampin MOA
Inhibits DNA-dependent bacterial RNA polymerase.
Spectrum of Rifampin
G +, G-, and mycobacteria, (TB, leprosy, and legionella) also Type B influenza
What is unique about rifampin?
Make you pee orange, cry orange etc CYP450 INDUCER (anti-anticontraceptive)
What is the MOA of Nitrofurantoin?
form highly reactive intermediates
What would you use Nitrofurantoin against?
UTIs and prophylaxis of UTIs
Reasons to avoid Nitrofurantoin?
Hepatotoxicity, neuropathy, drug-induced lupus
Contraindications: people with decrease renal function,
last 4 weeks of pregnancy or neonates up to a month due to risk of hemolytic anemia
Why is nitrofurantoin so great against UTIs?
Highly absorbed in gut, excreted unchanged into kidney and not metabolized. It is not very penetrable into tissues.
