The pharmacokinetic properties of phenazopyridine hydrochloride have not been determined. Phenazopyridine and its metabolites are rapidly excreted by the kidneys. In a small number of healthy subjects, 90% of a 600 mg/day oral dose of phenazopyridine hydrochloride was eliminated in the urine in 24 hours, 41% as unchanged drug and 49% as metabolites.

Phenazopyridine HCl is indicated for the symptomatic relief of pain, burning, urgency frequency, and other discomforts arising from irritation of the mucosa of the lower urinary tract caused by infection, trauma, surgery, endoscopic procedures, or the passage of sounds or catheters.

The use of phenazopyridine for relief of symptoms should not delay definitive diagnosis and treatment of causative conditions. The drug should be used for symptomatic relief of pain and not as a substitute for specific surgery or antimicrobial therapy.

Phenazopyridine is compatible with antimicrobial therapy and can help relieve pain and discomfort during the interval before antimicrobial therapy controls the infection.

Treatment of a urinary tract infection with phenazopyridine should not exceed 2 days. There is no evidence that the combined administration of phenazopyridine and an antimicrobial provides greater benefit than administration of the antimicrobial alone after 2 days. (See Dosage and Administration.)