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Phenazopyridine (Monograph)

Brand names: Azo-Dine, Azo-Gesic, Azo-Natural, Azo-Standard, Baridium, ... show all 9 brands
Drug class: Antipruritics and Local Anesthetics
VA class: GU100
CAS number: 136-40-3

Medically reviewed by Drugs.com on Aug 22, 2023. Written by ASHP.

Introduction

Analgesic or local anesthetic; an azo dye.

Uses for Phenazopyridine

Urinary Tract Mucosal Anesthesia or Analgesia

Symptomatic relief of pain, burning, urgency, frequency, and other discomforts resulting from irritation of the lower urinary tract mucosa caused by infection, trauma, surgery, endoscopic procedures, or the passage of sounds or catheters.

Use should not delay definitive diagnosis and treatment of cause; not a substitute for specific surgery or anti-infective therapy.

Used in combination with appropriate anti-infective agents for initial treatment (first 2 days) of uncomplicated urinary tract infections when pain, burning, or urgency relief is needed. However, there is lack of evidence that such combinations provide greater benefit than an anti-infective agent alone after 2 days; continue treatment after 2 days with anti-infective agent alone.

Also may be used for self-medication for the symptomatic relief of minor pain, urgency, frequency, and burning on urination.

Phenazopyridine Dosage and Administration

Administration

Administer orally after meals.

Dosage

Available as phenazopyridine hydrochloride; dosage expressed in terms of the salt.

Pediatric Patients

Urinary Tract Mucosal Anesthesia or Analgesia
Relief of Irritation Due to Trauma, Surgery, Endoscopic Procedures, or the Passage of Sounds or Catheters
Oral

12 mg/kg daily, in 3 divided doses.

Discontinue when pain and discomfort are relieved, usually after 3–15 days.

Relief of Irritation Due to Infection
Oral

12 mg/kg daily, in 3 divided doses, for no more than 2 days; use in combination with an anti-infective agent and then continue therapy with anti-infective agent alone.

Adults

Urinary Tract Mucosal Anesthesia or Analgesia
Relief of Irritation Due to Trauma, Surgery, Endoscopic Procedures, or the Passage of Sounds or Catheters
Oral

Usually, 200 mg 3 times daily.

Discontinue when pain and discomfort are relieved, usually after 3–15 days.

Relief of Irritation Due to Infection
Oral

Usually, 200 mg 3 times daily for no more than 2 days; use in combination with an anti-infective agent and then continue therapy with anti-infective agent alone.

Self-Medication
Oral

190 mg 3 times daily for up to 2 days.

Consult clinician if symptoms persist for >2 days.

Prescribing Limits

Pediatric Patients

Urinary Tract Anesthesia or Analgesia
Relief of Irritation Due to Infection
Oral

Maximum 12 mg/kg daily, in 3 divided doses, for no more than 2 days.

Adults

Urinary Tract Anesthesia or Analgesia
Relief of Irritation Due to Infection
Oral

Maximum 200 mg 3 times daily for no more than 2 days.

Self-Medication
Oral

Maximum 190 mg 3 times daily for no more than 2 days.

Cautions for Phenazopyridine

Contraindications

Warnings/Precautions

General Precautions

Skin and/or Sclerae Discoloration

Discontinue if yellowish color of the skin or sclerae occurs (may indicate accumulation resulting from renal impairment).

Urine Discoloration

Urine may become orange to red in color, and may stain fabric; remove stains by soaking fabric in a 0.25% sodium dithionate or sodium hydrosulfite solution.

Self-medication

Discontinue and consult a clinician if pain and discomfort persist for longer than 2 days.

Use of Fixed Combination

When used in fixed combination with other agents, consider the cautions, precautions, and contraindications associated with the concomitant agents.

Specific Populations

Pregnancy

Category B.

Lactation

Not known whether phenzopyridine or metabolites are distributed into milk.

Hepatic Impairment

Contraindicated in severe hepatic impairment.

Renal Impairment

Possible accumulation of phenazopyridine; use is contraindicated.

Drug Interactions

Specific Laboratory Tests

Test

Interaction

Comments

Spectrometry or color reaction urinalysis; phenolsulfonphthalein (PSP) excretion test of kidney function.

Butanol may be used to extract phenazopyridine from the final alkaline urine dilution to give accurate results

Urinary glucose tests: glucose oxidase reagent (Clinistix, Tes-Tape)

Delayed reactions with glucose oxidase reagent may be interpreted as false-negative reactions; occasional false-positive tests occur with Tes-Tape

Cupric sulfate (Clinitest) is not affected

Urinary bilirubin tests (e.g., Ictotest)

May give false-positive results for the foam test and atypical color reactions with p-nitrobenzene diazonium p-toluene sulfonate reagent (Ictotest)

Urinary ketone tests using sodium nitroprusside (Acetest, Ketostix) or Gerhardt ferric chloride

May produce interfering colors

Prevent by adding a small amount of sodium dithionate to urine before performing the tests

Urinary protein tests

May discolor bromophenol blue test areas of commercial reagent strips and interfere with the nitric acid ring test

Sulfosalicylic acid and heat-acetic acid tests are unaffected

Determination of urinary steroids

May interfere by affecting absorbancy in the modified Glenn-Nelson method of 17-hydroxycorticosteroid determination and the Holtorff-Koch modification of the Zimmerman reaction for determining 17-ketosteroids

Urinary urobilinogen determinations (Ehrlich’s reagent)

Color interference

Spectrophotofluorimetric screening tests and assays for porphyrins

May produce falsely elevated readings

Phenazopyridine Pharmacokinetics

Pharmacokinetic properties have not been determined.

Distribution

Extent

Trace amounts may enter the CSF.

Trace amounts may cross the placenta; not known if distributed into milk.

Elimination

Metabolism

May be metabolized in the liver and other body tissues; metabolites not identified.

Elimination Route

Excreted principally in urine as unchanged drug (up to 65%); small amounts excreted in feces.

Stability

Storage

Oral

Tablets

Tight containers at 15–30°C.

Actions

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Phenazopyridine Hydrochloride

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Oral

Tablets

95 mg

Azo-Gesic

Major

Azo-Standard

PolyMedica

Prodium

Requa

97 mg

Re-Azo

Reese

97.2 mg

Azo-Dine

Republic

Azo-Natural

Cemco

Baridium

Pfeiffer

UTI Relief

Consumers Choice

100 mg*

Pyridium

Warner Chilcott

200 mg*

Pyridium

Warner Chilcott

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Phenazopyridine Hydrochloride Combinations

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Oral

Tablets

150 mg with Butabarbital 15 mg, and Hyoscyamine Hydrobromide 0.3 mg*

Pyridium Plus (with parabens)

Warner-Chilcott

AHFS DI Essentials™. © Copyright 2024, Selected Revisions September 1, 2005. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

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