Methenamine Flashcards
What effect does Methenamine have?
No antibacterial effect alone
What must occur before Methenamine becomes useful?
Hydrolyzed to formaldehyde under adequate urine pH
Where does absorption occur?
Methenamine
GI tract
What is an issue seen in the GI? How is it avoided?
Methenamine
Hydrolysis by gastric acid (moa requires urine pH)
Enteric coated formulations avoid hydrolysis
Why should Methenamine be avoided in hepatic insufficiency?
Ammonia byproduct
Renal failure - acid forms could potentially lead to systemic acidosis
What organisms are susceptible to formaldehyde?
bacteria and fungi
What stops conversion to formaldehyde?
urease positive bacteria (Proteus) - alkanize in urine
Factors affecting formaldehyde concentrations
rate of hydrolysis
rate of urine loss from bladder by voiding or drainage
How does frequent voiding of bladder affect treatment?
decrease effects by removing formaldehyde and by reducing the time of exposure of bladder bacteria to formaldehyde
What is Methenamine used for?
UTI prophylaxis only
Are Methenamine reccomended for treatment of acute UTIs?
NO
