Quinolones and Tetracyclines Flashcards
What is the MoA for quinolones?
Targets DNA gyrase and topoisomerase IV
Bactericidal
Exhibits postantibiotic effect
What are the new warnings associated with fluoroquinolone?
Hypoglycemic coma and aortic aneurysm in elderly
Diabetic coma and neuropsychiatric warnings
Which quinolones are mostly renally excreted?
Ofloxacin and Levofloxacin
What are the ADRs for quinolones?
Hypersensitivity
Hematologic - neutropenia/eosinophilia
QT prolongation
Diarrhea
Nephrotoxicity
CNS
MSK - arthropathy/tendon rupture
What are the drug interactions with quinolones?
Theophylline - ciprofloxacin can double levels
Warfarin - increased anticoagulant effect
Levofloxacin has little to no effect on either
What substance shouldn’t be given within 2-4 hours of quinolone dose?
Antacids
Iron
Sucralfate
Multivitamins
Which quinolones have better staph/strep coverage?
Levofloxacin
Moxifloxacin
Gemifloxacin
Which quinolones have SPACE coverage?
Cipro and levofloxacin
What is the only quinolone with anaerobic coverage?
Moxifloxacin
Describe the coverage of ciprofloxacin
Considered poor for G +
Most potent of the quinolones against G-, specifically Pseudomonas
Excellent bioavailability
Describe the coverage of levofloxacin/gemifloxacin/moxifloxacin.
G+ coverage (PCN resistant Strep pneumo, Staph)
G- negative coverage - Levo for SPACE, gemi and moxi for SACE
All have atypical coverage
What is unique about moxifloxacin coverage?
Anaerobes for complicated intra-abdominal infections
Does not cover UTIs
What is the dose and coverage for Delafloxacin (Baxdela)?
Dose: IV 300mg BID or PO 450mg BID
Coverage: Staph/Strep/MRSA, E. coli, Klebsiella, Pseudomonas
How is delafloxacin different from other FQNs?
Has not demonstrated QT prolongation or phototoxicity
No markers of ADRs to liver, kidneys or glucose control
What are the mechanisms of resistance against quinolones?
Altered target enzyme
Altered drug permeability and efflux of drug
What is the MoA for tetracyclines?
Reversibly binds to 30S ribosomal subunit, decreasing protein synthesis
Bacteriostatic
What is the bioavailability of tetracyclines?
Doxy and Minocycline 90-100%
Tetra, demeclo, oxytetra - 58-75%
Which tetracyclines are eliminated via renal excretion?
Tetracycline
Oxytetracycline
Demeclocycline
Which tetracyclines are eliminated via hepatobiliary excretion?
Coxycycline
Minocycline
What are the ADRs for tetracyclines?
Photosensitivity
Discoloration of developing teeth
Reversible diabetes insipidus associated with Demeclocycline (can be used to treat SIADH)
What ADRs are associated with minocycline?
Vestibular side effects
Sizziness, ataxia, vertigo
What ADR is associated with the citric acid formulation of tetracycline?
Fanconi-like syndrome
N/V, lethargy, polydipsia, polyuria, proteinuria, acidosis, hypokalemia
What are the drug interactions with tetracyclines?
Decreased absorption when co-administered via chelation (cations, antacids, dairy)
Potential antagonism effect due to static effect, cidal agents require active growth
Enhances anticoagulation of warfarin
What is the spectrum of activity for tetracyclines?
Broad Spectrum Coverage
G+ and G-
Atypicals
Rickettsia
What are the clinical uses for tetracyclines?
Rikettsia infection
M. pneumonia
Chlamydia
Acne
H. pylori in combination with other agents
What is Brucellosis and its treatment?
Similar to flu symptoms, caused by Brucella from unpasteurized cheeses, milk
Tetracycline + Gentamicin
Severe infections of CNS or endocarditis may occur
What acute diarrheal disease are tetracyclines used for?
Vibrio cholera or vulnificus
What is Borrelia burgdorferi?
Causes Lyme disease
Bull’s-eye rash with flue like symtpoms
Treated with tetracyclines
What is the atypical use for demeclocycline?
SIADH
