Sulfa, Trimethoprim and Quinolones Flashcards
Sulfonamide
Sulfanilamide nucleus with attached amido or amino groups
Sulfonamide MOA
synthetic analog of PABA, inhibits bacterial enzyme dihydropteroate synthetase, inhibit bacterial folic acid synthesis by inhibiting the incorporation of PABA into folic acid
Sulfonamides
Gram (+): strep, staph, listeria, Gram (-): entero, other: pneumo, nocardia
Resistance to Sulfonamides
Overproduction of PABA, altered dihydropteroate synthetase, decreased permeability
Sulfonamide Kinetics
good absorption, wide distribution, penetrate CSF, highly protein bound
Sulfonamide Kinetics
metabolized, inhibitor of 2C9, renal elimination
Sulfonamide ADR
GI, photosensitivity, rash, angioedema, hematologic, avoid in neonates, interstitial nephritis
Trimethoprim MOA
inhibits dihydrofolate reductase, acts similarly to sulfa for spectrum of activity. ADE: increased SCr. hyperkalemia
CA-MRSA drugs of choice
Bactrim, Doxycycline, Clindamycin
Quinolone Structure
Two rings and and Fluorine Atom
Quinolone MOA
intracellular, inhibit DNA synthesis by interfering with DNA gyrase and topoisomerase, conc. dependent killing, cidal
Mechanisms of resistance to Quinolones
mutations in gyrase and topoisomerase, efflux, decreased permeability
Quiniolone Kinetics
complete absorption in absence of Ca, Mg, Zn, Fe, Al, (can decrease F by 90%), wide distribution, no CNS penetration
Quinolone Kinetics
cipro inhibits cyp1A2, renal elimination except moxifloxacin
Quinolone Drug Interactions
antacids, sucralfate, nutritional supplements, warfarin, QT prolongers
