indication
For the symptomatic relief of pain, burning, urgency, frequency, and other discomforts arising from irritation of the lower urinary tract mucosa caused by infection, trauma, surgery, endoscopic procedures, or the passage of sounds or catheters.
pharmacology
Phenazopyridine is a local anesthetic that has been used in urinary tract disorders. Its use is limited by problems with toxicity (primarily blood disorders) and potential carcinogenicity.
mechanism of action
Phenazopyridine's mechanism of action is not well known, and only basic information on its interaction with the body is available. It is known that the chemical has a direct topical analgesic effect on the mucosa lining of the urinary tract.
toxicity
Methemoglobinemia generally follows a massive, acute overdose.
biotransformation
Likely hepatic but also in other tissues. One of the metabolites is acetaminophen.
half life
7.35 hours
route of elimination
40% hepatic