macrolides, fluoroquinolones, TB, influenza Flashcards
macrolide MOA
reversibly bind 50s ribosome -> inhibit RNA dependent protein synthesis
bacteriostatic
macrolide agents
erythromycin, clarithromycin, azithromycin
macrolide ADME (ROA, metabolism, and extra effects)
oral, IV, ophthalmic
oxidized by CYP450; inhibit CYP3A4
erythromycin, clarithromycin also act as motilin receptor agonists in the gut and gallbladder to increase GI motility
macrolide use; which for H. flu? which for H. pylori?
CAP
azithromycin for H. flu; clarithromycin for H. pylori
improve GI motility
macrolide AE’s
GI intolerance
increased QT interval
hepatitis
phlebitis (erythromycin thrombophlebitis -> infuse slowly)
fluoroquinolone agents
levofloxacin norfloxacin ofloxacin ciprofloxacin gemifloxacin moxifloxacin
fluroquinolone MOA
inhibit DNA gyrase and topoisomerase IV enzymes -> promote cleavage of DNA
rapidly bacteriocidal
fluoroquinolone ADME (ROA, metabolisms)
IV, oral, topical; good for IV- oral deescalation
cipro, levo: renal metabolism
moxi: hepatic metabolism, can’t use for UTI
fluoroquinolone use; which for S. pneumo?
broad spectrum but resistance has developed, esp. Gr-‘s
for s. pneumo - levo, moxi, gemi
typical CAP bacteria + chlamydophila pneumo.
fluoroquinolone AE’s
increased risk of tendon rupture, tendinitis, and peripheral neuropathy prolonged QT hypersensitivity CDAD muscle and joint disorders in ped's blood glucose disturbances
fluoroquinolone drug interactions
multivalent cations
slows warfarin and anti-diabetic metabolism
drug for abx and GI tract stimulation
erythromycin
drug for peptic ulcer disease (H. pylori)
clarithromycin
drugs that cover legionella, mycoplasma
azithromycin, levofloxacin
treatment for active TB and latent TB
active TB: 4 drugs (INH, RIF, EMP, PZA) for 6-9 months
latent TB: usually INH for 9 months with DOT
Isoniazid MOA and AE’s
inhibit mycolic acid synthesis
hepatic enzyme elevation / hepatitis, peripheral neuropathy, interaction with phenytoin and -azoles
monitor AST and discontinue if 3x ULN with sx or 5x ULN without
rifamycin’s MOA and AE’s
inhibit RNA polymerization; bactericidal
hepatitis, GI upset, rash, flu-like sxs, orange-red body fluids
monitor AST and discontinue if 3x ULN with sx or 5x ULN without
rifamycin’s use
Rifampin - TB and Gr+’s and Gr-‘s but resistance develops QUICKLY - don’t administer alone for active disease
Rifaximin - only 0.4% absorbed; used for diarrhea, hepatic encephalopathy
Influenza Tx options (A vs A and B)
A - M2 proton channel blockers (amantadine, rimantadine)
resistance common
B - Neuraminidase inhibitors (oseltamivir, peramivir, zanamivir)
Neuraminidase inhibitor ROA and use
oseltamivir - oral zanamivir - inhaled peramivir - IV influenza tx (modest impact if given within 48 hrs onset) or chemoprophylaxis for 7 days or more
Oseltamivir MOA
binds neuraminidase and inhibits dissolution of sialic acid -> no viral budding or replication, promotes viral clumping
Oseltamivir AE’s
nausea, vomiting
serious skin reactions
sporadic transient neuropsychiatric events, esp. in Japanese
