click below
click below
Normal Size Small Size show me how
USMLE
New FA Micro 4
Question | Answer |
---|---|
which has greater oral availability - amoxicillin or ampicillin? | amOxicillin |
spectrum of ampicillin, amoxicillin | "HELPS kill enterococci": h. flu, e. coli, listeria, proteus, salmonella, enterococci |
cefazolin and cephalexin are what generation cephalosporins? | first |
coverage of cefazolin and cephalexin? | "PEcK": proteus, e. coli, klebsiella (and gram positives) |
cefoxitin, cefaclor, cefuroxamine are what generation? | second |
coverage of cefoxitin, cefaclor, cefuroxamine? | "HEN PEcKS:" h. flu, enterobacter, neisseria, proteus, e. coli, klebsiella |
ceftriaxone, cefotaxime, and ceftazidime are what generation? | third |
use of ceftriaxone, cefotaxime, and ceftazidime? | serious gram-negative infections resistant to other beta lactams; meningitis; ex. ceftazidime for pseudomonas, ceftriaxone for gonorrhea |
cefepime, cefpiramide belong to what generation? | fourth |
use of cefepime, cefpiramide? | increased activity against pseudomonas and gram-positive organisms |
serum-like sickness in infants and kids can be seen with what cephalosporin? | ceflacor (2nd generation) |
this is an inhibitor of renal dihydropeptidase I | cilastin - decreases inactivation of imipenem in renal tubules |
why are aminoglycosides ineffective against anaerobes? | require O2 for uptake |
drug used for bowel surgery? | neomycin |
this tetracycline is an ADH antagonist - acts as a diuretic in SIADH | demeclocylcine |
clinical use of tetracyclines? | VACUUM THe BedRoom: vibrio cholerae, acne, chlamydia, ureaplasma urealyticum, mycoplasma, tularemia, h. pylori, borrelia burgdorferi, rickettsia |
this drug treats anaerobes above the diaphragm | clindamycin |
these drugs can cause leg cramps and myalgias in kids | fluoroquinolones |
used for anaerobes below the diaphragm | metronidazole |
how does nystatin work? | binds to ergosterol, disrupting fungal membranes (too toxic for systemic use) |
mechanism of the -azoles? | inhibit fungal steriod (ergosterol) synthesis |
toxicities of -azoles? | hormone synthesis inhibition (gynecomastia), liver dysfunction (inhibition of P450), fever, chills |
this antifungal inhibits DNA synthesis by conversion to fluorouracil, which competes with uracil | flucytosine |
toxicity of flucytosine | nausea, vomiting, diarrhea, bone marrow suppression |
mechanism of caspofungin? | inhibits cell wall syntehsis |
use of caspofungin? | invasive aspergillosis |
toxicity of caspofungin? | GI upset, flushing |
this antifungal inhibits the fungal enzyme squalene epoxidase | terbinafine |
use of terbinafene? | used to treat dermatophytoses (especially onychomycosis) |
mechanism of griseofulvin? | interferes with microtubule function; disrupts mitosis; depostis in keratin-containing tissues (e.g. nails) |
clinical use of griseofulvin? | oral treatment of superficial infections; inhibits growth of dermatophytes (tinea, ringworm) |
toxicity of griseofulvin? | teratogenic, carcinogenic, confusion, headaches, increases warfarin metabolism |
two diseases transmitted by inhalation fo asexual spores? | coccidiomycosis and histoplasmosis |
treatment for superficial candidal infection? for systemic? | nystatin; amphotericin B |
Southwestern US, valley fever | coccidiomycosis |
Mississippi and Ohio river valleys | histoplasmosis |
rural Latin America | paracoccidiomycosis |
bird or bat droppings; intracellular (tiny yeast inside macrophages) | histoplasmosis |
Captain's wheel appearance | paracoccidiomycosis |
states east of Mississippi River and Central America | blastomycosis |
big, broad-based budding | blastomycosis |
dimorphic fungi | mold in soil; yeast in tissue |
on what do you culture fungi? | Sabouraud's agar |
systemic mycoses can mimic what? | TB (granuloma formation) |
what is cocidiomycosis in tissue? | spherule |
treatments for mycoses? | fluconazole or ketoconazole for local infection; ampho B for systemic infection |
what causes tinea versicolor? | malassezia furfur |
hypopigmented skin lesions in hot, humid weather | tinea versicolor |
treatment for tinea versicolor? | topical miconazole, selenium sulfide |
what does cladosporium werneckii cause? | tinea nigra |
infection of keratinized layer of skin; appears as brownish spot | tinea nigra |
treatment for tinea nigra? | salicylic acid |
pruritic lesions with central clearing resembling a ring, caused by dermatophytes | tinea pedis/cruris/corporis/capitis |
mold hyphae in KOH prep, not dimorphic | tinea pedis/cruris/corporis/capitis |
mold with septate hyphae that branch at a V-shaped (45 degree) angle | aspergillus |
culture on Sabourauds' agar, stains with India ink? | cryptococcus neoformans |
heavily encapsulated yeast, not dimorphic, found in soil & pigeon droppings | cryptococcus |
fungus ball | aspergillus |
mold with irregular nonseptate hyphae branching at wide angles (>90 degrees) | mucor and rhizopus |
in what type of patients is mucormycosis typically seen? | ketoacidotic diabetic and leukemic patients |
fungi proliferate in walls of blood vessels and cause infarction of distal tissue; rhinocerebral, frontal lobe abscesses | mucor and rhizopus |