ABs that are inhibitors of Nucleic Acid Synthesis Flashcards
what are the 3 ABs that are inhibitors of nucleic acid synthesis
sulfonamides, trimethoprims, and rifampin
MoA of sulfonamide?
static or cidal
selectivity?
spectrum: gram - or gram +
Sulfonamides are competitive inhibitors of dihydropteroate synthase this inhibiting synthesis of folic acid
static!!
act on both gram - AND gram +
selective against bacteria bc humans don’t produce their folate that get it from diet
what are the clinical uses of sulfonamides?
UI, toxoplasmosis, Malaria, prophylactic
Sulfonamides
absorption:
distribution/ excretion:
Toxicity
sulfonamides taken orally crosses BBB excreted really dose related and dose unrelated toxicities
what are the dose related toxicities of sulfonamides
Crystalluria- take with lots of water!
hemolytic anemia
GI upset
Kernicterus- displaces albumin bound bilirubin, in newborns this will allow bilirubin to cross BBB leading to encephalopathy
what are the dose UNRELATED toxicities of sulfonamides
hypersensitivity- Stevens Johnson syndrome
photosensitivity
What is the special note about sulfonamides?
DO NOT use in newborns! causes kernicterus- bilirubin passing BBB and causing encephalopathy
What AB is a inhibitor of dihydrofolate reductase, a structural analog of ptreridine?
static or cidal? MoA
trimethoprim, MoA = inhibitor of folic acid synthesis
STATIC!
Trimethoprim spectrum?
clinical uses?
trimethoprim is effective against gram - and gram + = broad spectrum
clinically used for: UI, prostatitis, Pneuomocystis jarovecil (in AIDS pts)
TX for community acquired MRSA
Community acquire MRSA can be treated with what?
trimethoprim
Trimethoprim toxicities a mild but can result in what
absorption:
distribution:
Trimethoprim taken orally, penetrates CNS, excreted renally, can cause blood Dyscrasias
and can cause anemias
What AB bind to and inhibits RNA polymerase?
is this drug static or cidal?
Route of admin?
rifampin
CIDAL!
taken orally
Rifampin is used to treat what and how?
Spectrum of rifampin?
Rifampin is used in combo with other drugs as 1st line of defense against TB
Spectrum: M tuberculosis and some staphylcocci
Rifampin is used to treat TB, what else it is used to treat?
Rifampin is used to resistant staph infections, meningitis
What is important to tell pts when taking Rifampin about the distribution of the drug?
Rifampin causes urine, feces, saliva, sputum, and tears to turn red orange
