UT agents Flashcards
the two UT agents
nitrofurantion and methenamine
MOA methenamine
hydrolyzed at low pH to generate ammonia and formaldehyde which is a nonspecific protein denaturant
spectrum of activity of nitrofurantoin
organisms that cause UTI
E. coli, citrobacter, group B strep, staph, enterococcus (including VRE strains)
MOR methenamine
no mechanism of resistance as formaldehyde is a pretty nonspecific killer
only resistance may be due to alkanization of urine (proteus infections) which will inhibit methenamine conversion to formaldehyde
clinical use of nitrofurantion
only indication is the treatment and prophylaxis of acute, uncomplicated, nerf-ball UTIs
clinical use of methenamine
suppression or prophylaxis of recurrent lower UTIs
contraindicated in the treatment of established UTIs or in patients with indwelling catheters
unique side effect to nitrofurantoin
pulmonary reactions hours to weeks after drugs exposure
methenamine contraindicated in patients with…
hepatic insufficiency
nitrofurantoin contraindicated in patients with…
renal insufficiency
organisms susceptible to nitrofurantoin but don’t cause UTIs…
salmonella and shigella
