Antibiotics Flashcards
Treatment of Mycobacterium tuberculosis?
Isoniazid, Rifampin, Ethambutol, Pyrazinamide
Mechanism of Isoniazid
Inhibits mycolic acids, which is a component of mycobacterial cell wall
*Fast liver acetylators will require higher dose!
Mechanism of Rifampin
RED tears; inhibits DNA-dependent RNA polymerase
induces formation of drug-metabolizing enzymes (CYP450)
Mechanism of Ethambutol
inhibits cell wall synthesis by binding arabinosyl transferase
Treatment of Cryptococcus neoformans?
Liposomal Amphotericin and Flucytosine, followed by fluconazole until negative culture for 3-12 months
Characteristics of Cryptococcus neofromans
- inhaled as spores
- disseminated hematogenously to CNS in immunocompromised
- stains with India ink or latex agglutination
- common in Africa
Mechanism of Amphotericin B
- Disrupts plasma membranes of fungi creating holes allowing leaking of electrolytes
- BROAD spectrum (yeasts and molds)
- liposomal form enters CNS
- nephrotoxic due to binding of cholesterol
Mechanism for Fluconazole
-binds fungal P450 to block ergosterol synthesis
-Spectrum: systemic mycoses (dimorphic fungi and yeast)
-Substrate for efflux pump in brain
-Drug-Drug interactions, hepatoxicity, neurotoxicity - AVOID when Prego
Resistance: altered CYP450, increased efflux
Treatment for Candida albicans?
Fluconazole or
Flucytosine with Amphotericin B
Mechanism of Flucytosine (5-FC), Itraconazole, Voriconazole (CNS)
- Antimetabolite converted to 5-Fluorouracil - DNA/RNA synthesis inhibitor
- NARROW spectrum (yeast)
- penetrates CNS
- can cause bone marrow suppression
- Resistance: loss of converting enzyme; co-treat with Amphotericin B to increase uptake
Treatment for Hypori influenza Type B
Rifampin as meningococcal prophylaxis
Mechanism for Ceftriaxone (3rd Generation Cephalosporin)
Cell wall inhibitor that binds to penicillin binding proteins; penetrates CNS
Treatment for Neisseria gonorrhoeae
Ceftriaxone
Empiric treatment of bacterial meningitis
Ceftriaxone and Vancomycin
Treatment for Neisseria meningitis
Ceftriaxone
Empiric treatment of brain abscess
Ceftriaxone and Metronidazole
Mechanism of Penicilin
Cell wall inhibitor that binds to penicillin binding proteins; Gram Positive only
Treatment of intrapartum prophylaxis for Strptococcus agalactiae (Strep B)
Penicillin
Mechanism of Amoxicillin, Ampicillin
Cell wall inhibitor that binds to penicillin binding proteins
-often administered with clavulanate to inactivate enzymatic degradation by beta-lactamases
Treatment for otitis media
Amoxicillin
Treatment for sinusitis
Amoxicillin
Treatment for Listeria monocytogenes meningitis
Ampicillin and Gentamicin
Mechanism of Aztreonam
Cell wall inhibitor that binds to penicillin binding proteins
Empiric treatment for meningitis if beta-lactam allergy?
Aztreonam and Vancomycin
