Phenazopyridine

INDICATIONS AND USAGE Phenazopyridine HCl is indicated 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. The use of Phenazopyridine HCl for relief of symptoms should not delay definitive diagnosis and treatment of causative conditions. Because it provides only symptomatic relief, prompt appropriate treatment of the cause of pain must be instituted and Phenazopyridine HCl should be discontinued when symptoms are controlled. The analgesic action may reduce or eliminate the need for systemic analgesics or narcotics. It is, however, compatible with antibacterial therapy and can help to relieve pain and discomfort during the interval before antibacterial therapy controls the infection. Treatment of a urinary tract infection with Phenazopyridine HCl should not exceed 2 days because there is a lack of evidence that the combined administration of Phenazopyridine HCl and an antibacterial provides greater benefit than administration of the antibacterial alone after 2 days. (See DOSAGE AND ADMINISTRATION section.)

DOSAGE AND ADMINISTRATION 100 mg Tablets: Average adult dosage is two tablets 3 times a day after meals. 200 mg Tablets: Average adult dosage is one tablet 3 times a day after meals. When used concomitantly with an antibacterial agent for the treatment of a urinary tract infection, the administration of Phenazopyridine HCl should not exceed 2 days. To report SUSPECTED ADVERSE REACTIONS, contact Winder Laboratories, LLC at 1-770-307-0703, or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

WARNINGS Phenazopyridine Hydrochloride is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity in experimental animals (IARC 1980, 1982, 1987, NCI 1978). When administered in the diet, Phenazopyridine hydrochloride increased the incidences of hepatocellular adenomas and carcinomas in female mice and adenomas and adenocarcinomas of the colon and rectum in rats of both sexes. There is inadequate evidence for the carcinogenicity of Phenazopyridine hydrochloride in humans (TARC 1987). In one limited epidemiological study, no significant excess of any cancer was observed among 2,214 patients who received Phenazopyridine hydrochloride and were followed for a minimum of 3 years.

CONTRAINDICATIONS Phenazopyridine Hydrochloride should not be used in patients who are hypersensitive to the drug or its ingredients. Phenazopyridine Hydrochloride is contraindicated in patients with renal insufficiency, severe liver disease, severe hepatitis or pyelonephritis of pregnancy. It should be used cautiously in the presence of GI disturbances.

Drug Interactions The interaction of Phenazopyridine Hydrochloride with other drugs has not been studied in a systematic manner. However, the medical literature to date suggests that no significant interactions have been reported.

ADVERSE REACTIONS The following adverse events have been reported: CNS: headache. Gastrointestinal: nausea, vomiting and diarrhea. Dermatologic and Hypersensitivity: rash, pruritus, discoloration, anaphylactoid-like reaction and hypersensitivity hepatitis. Hematologic: methemoglobinemia, hemolytic anemia, potential hemolytic agent in G-6-PD deficiency, sulfhemoglobinemia. Other: visual disturbances, renal and hepatic toxicity usually associated with overdose, renal calculi, jaundice, discoloration of body fluids and aseptic meningitis.

CLINICAL PHARMACOLOGY Phenazopyridine hydrochloride is excreted in the urine where it exerts a topical analgesic effect on the mucosa of the urinary tract. This action helps to relieve pain, burning, urgency and frequency. The precise mechanism of action is unknown. PHARMACOKINETICS The pharmacokinetic properties of Phenazopyridine hydrochloride have not been determined. Phenazopyridine Hydrochloride 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.