FDA label 677fbdd8-4cf8-10c8-e053-2991aa0a7312

Disclaimer: This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA. For further information about unapproved drugs, click here.

Phenazopyridine hydrochloride is reasonably anticipated to be a human carcinog en based o n sufficient evidence o f carcinogenicity in experimental animals (IARC 19 8 0 , 19 8 2, 19 8 7, NCI 19 78 ). When administered in the diet, Phenazopyridine hydrochloride increased the incidences o f hepatocellular adenomas and carcinomas in female mice and adenomas and adenocarcinomas o f the co lo n and rectum in rats o f both sexes. T here is inadequate evidence for the carcinogenicity o f Phenazopyridine hydrochloride in humans (T ARC 19 8 7). In o ne limited epidemiological study, no significant excess o f any cancer was observed among 2,214 patients who received Phenazopyridine hydrochloride and were followed for a minimum o f 3 years. PRECAUT IONS General: T he patient should be advised that Phenazopyridine produces an o rang e to red co lo r in the urine and feces, and may cause staining . Phenazopyridine may cause disco lo ratio n o f body fluids and staining o f contact lenses has been reported. A yellowish co lo r o f the skin o r sclera may indicate accumulation o f Phenazopyridine resulting fro m impaired renal function and necessitates discontinuance o f the drug . It should be no ted that a decline in renal function is common in elderly patients. Phenazopyridine may mask pathological conditions and interfere with laboratory test values using colorimetric, spectrophotometric o r fluorometric analysis methods. Cautious use in patients with G-6 -PD deficiency is advised since these patients are susceptible to oxidative hemolysis and may have greater potential to develop hemolytic anemia. Information for Patients : T he patient should be advised to take Phenazopyridine with o r following foo d o r after eating a snack to reduce stomach upset. T he patients should be aware that Phenazopyridine causes a reddish o rang e disco lo ratio n o f the urine and feces, and may stain clothing . Phenazopyridine may cause disco lo ratio n o f body fluids and staining o f contact lenses has been reported. T here have been reports o f teeth disco lo ratio n when the pro duct has been bro ken o r held in the mouth prior to swallowing . Patients should be instructed to take Phenazopyridine for only 2 days if an antibacterial agent is administered concurrently for the treatment o f a urinary tract infection. If symptoms persist beyond those 2 days, the patient should be instructed to contact his o r her physician. Laboratory Tests : Phenazopyridine may interfere with laboratory test values using colorimetric, pho to metric o r fluorometric analysis methods. Altered urine laboratory test values may include ketone (sodium nitroprusside) , bilirubin (foam test, talc-disk-Fouchet-spot test, Franklin 's tablet-Fouchet test, p-nitro benzene diazonium p-toluene sulfonate reag ent), diacetic acid (Gerhardt ferric chloride test), free hydrochloric acid, glucose (glucose oxidase tests), 17-hydroxycorticosteroids (modified Glenn-Nelson), 17-keto steroids (Holtorff Koch modification o f Zimmerman), porphyrins, albumin (disco lo rs bro mophenol blue test areas o f commercial reagent strips, nitric acid ring test), phenolsulfophthalein , urobilinogen (co lo r interference with Ehrlich 's reagent), and urinalysis (spectrophotometric o r co lo r-based tests). Phenazopyridine also imparts an o rang e-red co lo r to stools which may interfere with co lo r tests. Drug Interactions : T he interaction o f Phenazopyridine with other drug s has no t been studied in a systematic manner. However, the medical literature to date suggests that no significant interactions have been reported. Carcinogenesis , Mutagenesis , Impairment o f Fertility: Long -term administration o f Phenazopyridine has been associated with tumors o f the large intestine in rats and o f the liver in mice. Available epidemiological data are insufficient to evaluate the carcinogenicity o f Phenazopyridine in humans. In vitro studies indicate that Phenazopyridine in the presence o f metabolic activation is mutagenic in bacteria and mutagenic and clastogenic in mammalian cells. Pregnancy Cate gory B: Reproductive studies with Phenazopyridine (in combination with sulfacytine) in rats given up to 110 mg /kg /day and in rabbits given up to 39 mg /kg /day during organogenesis revealed no evidence o f harm to offspring. One prospective study in human s demonstrated that Phenazopyridine traverses the placenta into the fetal compartment. T here are no adequate and well-controlled studies in pregnant women. Therefore, Phenazopyridine should be used in pregnant women only if the benefit clearly outweighs the risk. Nursing Mothers : It is no t known whether Phenazopyridine o r its metabolites arc excreted in human milk. Because many drug s are excreted in human milk, a decision should be made to discontinue nursing o r to discontinue the drug , taking into account the importance o f drug therapy to the mother. Children: Adequate and well-controlled studies have no t been performed in the pediatric population. No pediatric-specific problems have been documented.

T he following adverse events have been reported: CNS: headache. Gastro intestinal: nausea, vomiting and diarrhea. Dermatologic and Hypersensitivity: rash, pruritus, disco lo ratio n, 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, disco lo ratio n o f body fluids and aseptic meningitis.