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Pediatric Nephrology (Berlin, Germany) Nov 2006Phenazopyridine (Pyridium) is a commonly used urinary tract analgesic. It has been associated with yellow skin discoloration, hemolytic anemia, methemoglobinemia, and... (Review)
Review
Phenazopyridine (Pyridium) is a commonly used urinary tract analgesic. It has been associated with yellow skin discoloration, hemolytic anemia, methemoglobinemia, and acute renal failure, especially in patients with preexisting kidney disease. We report a 17-year-old female with vertically transmitted human immunodeficiency virus (HIV) infection, presenting with acute renal failure and methemoglobinemia following a suicidal attempt with a single 1,200 mg ingestion of Pyridium. She had no prior evidence of HIV nephropathy. The patient had a progressive nonoliguric renal failure on the 3rd day following the ingestion. She was treated with N-acetylcysteine, intravenous carnitine, and alkalinization of the urine. Her kidney biopsy revealed acute tubular necrosis with no glomerular changes. After 7 days of conservative management, she was discharged home with normal kidney function. To our knowledge, this is the second smallest amount of Pyridium overdose resulting in acute renal failure with no previous history of kidney disease.
Topics: Acetylcysteine; Acute Kidney Injury; Adolescent; Carnitine; Female; HIV Infections; Humans; Infectious Disease Transmission, Vertical; Methemoglobinemia; Phenazopyridine; Sodium Bicarbonate; Suicide, Attempted; Treatment Outcome
PubMed: 16897003
DOI: 10.1007/s00467-006-0196-1 -
Journal of Cellular and Molecular... Sep 2009Embryonic stem (ES) cells are powerful tools to understand mechanisms of neuronal differentiation and to engineer neurons for in vitro studies and cell therapy. We...
Embryonic stem (ES) cells are powerful tools to understand mechanisms of neuronal differentiation and to engineer neurons for in vitro studies and cell therapy. We developed a screening approach to identify small organic molecules driving neuronal differentiation of ES cells. For this purpose, we used a lentivector carrying a dual luciferase reporter system to engineer an ES cell line which allowed us to screen for small organic molecules enhancing neuronal differentiation. One of them, phenazopyridine, was further analysed in human ES cells. Phenazopyridine: (i) enhanced neuronal differentiation, (ii) increased cell survival, (iii) decreased the amount of non-neuronal and undifferentiated cells and (iv) synchronized the cellular differentiation state. Phenazopyridine allowed the development of a differentiation protocol compatible with the generation of clinical grade neural precursors, which were able differentiate into different neuronal subtypes, astrocytes and oligodendrocytes. In summary, we describe a powerful approach to identify small molecules directing stem cell differentiation. This led to the establishment of a new application for an old drug and the development of a novel clinical grade protocol for neuronal differentiation of ES cells.
Topics: Animals; Cell Culture Techniques; Cell Differentiation; Cell Lineage; Coculture Techniques; Embryonic Stem Cells; Humans; Mice; Microscopy, Fluorescence; Neurons; Phenazopyridine
PubMed: 20196783
DOI: 10.1111/j.1582-4934.2009.00660.x -
ChemMedChem Apr 2021Rev1 is a protein scaffold of the translesion synthesis (TLS) pathway, which employs low-fidelity DNA polymerases for replication of damaged DNA. The TLS pathway helps...
Rev1 is a protein scaffold of the translesion synthesis (TLS) pathway, which employs low-fidelity DNA polymerases for replication of damaged DNA. The TLS pathway helps cancers tolerate DNA damage induced by genotoxic chemotherapy, and increases mutagenesis in tumors, thus accelerating the onset of chemoresistance. TLS inhibitors have emerged as potential adjuvant drugs to enhance the efficacy of first-line chemotherapy, with the majority of reported inhibitors targeting protein-protein interactions (PPIs) of the Rev1 C-terminal domain (Rev1-CT). We previously identified phenazopyridine (PAP) as a scaffold to disrupt Rev1-CT PPIs with Rev1-interacting regions (RIRs) of TLS polymerases. To explore the structure-activity relationships for this scaffold, we developed a protocol for co-crystallization of compounds that target the RIR binding site on Rev1-CT with a triple Rev1-CT/Rev7 /Rev3-RBM1 complex, and solved an X-ray crystal structure of Rev1-CT bound to the most potent PAP analogue. The structure revealed an unexpected binding pose of the compound and informed changes to the scaffold to improve its affinity for Rev1-CT. We synthesized eight additional PAP derivatives, with modifications to the scaffold driven by the structure, and evaluated their binding to Rev1-CT by microscale thermophoresis (MST). Several second-generation PAP derivatives showed an affinity for Rev1-CT that was improved by over an order of magnitude, thereby validating the structure-based assumptions that went into the compound design.
Topics: Dose-Response Relationship, Drug; Drug Design; Enzyme Inhibitors; Humans; Molecular Structure; Nucleotidyltransferases; Phenazopyridine; Structure-Activity Relationship
PubMed: 33314657
DOI: 10.1002/cmdc.202000893 -
Environmental Technology Sep 2019Photocatalytic degradation of waste pharmaceutics, with solar radiation, is described here as a feasible method to purify pre-contaminated soils. Phenazopyridine has...
Photocatalytic degradation of waste pharmaceutics, with solar radiation, is described here as a feasible method to purify pre-contaminated soils. Phenazopyridine has been used as a model soil contaminant. Two different nano-size powders have been first examined as catalysts, namely commercial TiO (anatase) and commercial ZnO. As the ZnO showed higher catalytic efficiency, the study was then focused on it. The commercial ZnO powder was then compared with lab-prepared ZnO powder, and the latter shows relatively higher efficiency. The ZnO was used in two different ways. In one way, dry ZnO catalyst powder was spread onto the soil, while in the other way the ZnO was sprayed onto the soil surface by a wet spray method. The spray technique shows slightly higher efficiency, in addition to being easier to apply at future large scale. Depending on conditions and type of photocatalyst used, up to 90% contaminant removal can be achieved in 30 min. In case of photocatalysis experiments, the reacted contaminant molecules undergo complete degradation with no detectable side reaction organic products. Possible evaporation or escape of organic contaminant, or other possibly resulting organics, is ruled out by a series of control experiments. Photodegradation process takes place only at the catalytic sites on the soil surface, where contaminant molecules that diffuse from the soil bulk are completely degraded. Other useful organisms inside the soil are not affected as they are kept away from catalyst sites. A plausible mechanism is proposed for the degradation process.
Topics: Catalysis; Phenazopyridine; Photolysis; Soil; Sunlight; Zinc Oxide
PubMed: 29600741
DOI: 10.1080/09593330.2018.1459873 -
The American Journal of Medicine Sep 1991
Topics: Aged; Aged, 80 and over; Female; Humans; Methemoglobin; Phenazopyridine; Sulfhemoglobinemia
PubMed: 1892154
DOI: 10.1016/0002-9343(91)90135-k -
Environmental Science and Pollution... Oct 2023Pharmaceutical wastewater treatment is an essential component of environmental protection and sustainable development. In this study, our aim was to investigate the...
Pharmaceutical wastewater treatment is an essential component of environmental protection and sustainable development. In this study, our aim was to investigate the morphology, characterization, and effectiveness of TiO/graphene composite nanofiber photocatalysts in the treatment of pharmaceutical wastewater containing three different pharmaceutical groups, such as an antibiotic (rifampin), painkiller (phenazopyridine), and immunosuppressant (azathioprine). Various parameters such as pH, salt concentration, and initial pharmaceutical compound concentration were optimized to achieve maximum degradation kinetics and efficiency. The optimum conditions were determined to be 1.5% graphene content, 30 ppm initial concentration of pharmaceutical compound, pH=5, and a 0.5 g/L photocatalyst dose. The presence of salt slightly decreased the degradation kinetics, but it did not significantly affect the performance of the TiO/graphene composite nanofibers photocatalyst. At optimum condition, TiO/1.5% graphene composite nanofibers degraded 50% of phenazopyridine, 86.89% of rifampin, and completely azathioprine. Comparing with phenazopyridine, N heteroatom-rich molecule of azathioprine and hydroxyl-rich molecule of rifampin lead to being susceptible to photocatalytic degradation. The reuse of the photocatalyst in multiple cycles showed consistent performance, indicating its potential for practical and economic applications.
Topics: Phenazopyridine; Nanofibers; Azathioprine; Graphite; Rifampin; Titanium; Pharmaceutical Preparations; Catalysis
PubMed: 37747607
DOI: 10.1007/s11356-023-29869-9 -
Clinics and Practice Oct 2022Methemoglobinemia is a rare blood disorder characterized by the oxidation of heme iron from ferrous (Fe) to ferric (Fe) state, which increases oxygen affinity and...
Methemoglobinemia is a rare blood disorder characterized by the oxidation of heme iron from ferrous (Fe) to ferric (Fe) state, which increases oxygen affinity and impairs oxygen release to the tissue causing hypoxia. It can be congenital or acquired; however, most cases are acquired and caused by exogenous substances such as medications, chemicals, and environmental substances. Phenazopyridine is an over-the-counter urinary analgesic medication commonly used for symptomatic relief of dysuria and has been reported to cause methemoglobinemia. However, only a handful of cases of phenazopyridine-induced methemoglobinemia have been reported. We present a case of an 89-year-old female who presented with severe hypoxia, shortness of breath, headache, nausea, and dizziness caused by phenazopyridine-induced methemoglobinemia. She was found to have a methemoglobin level of 21.5% and was treated with methylene blue, leading to a rapid improvement of her symptoms. She was taking one over-the-counter phenazopyridine 200 mg tablet three times daily for two weeks for her chronic dysuria. This case highlights the need to have a high index of suspicion of phenazopyridine-induced methemoglobinemia in a patient presenting with unexplained shortness of breath with a history of phenazopyridine use as it could lead to severe methemoglobinemia with hypoxia that could potentially be fatal if not promptly diagnosed.
PubMed: 36412668
DOI: 10.3390/clinpract12060089 -
Annals of Family Medicine 2004Effective use of over-the-counter (OTC) medications depends on purchasers' knowledge of their indications. This study examines consumer knowledge regarding the urinary...
BACKGROUND
Effective use of over-the-counter (OTC) medications depends on purchasers' knowledge of their indications. This study examines consumer knowledge regarding the urinary tract analgesic phenazopyridine, which recently became available without prescription.
METHOD
We conducted a cross-sectional survey of a stratified cluster random sample of purchasers of OTC phenazopyridine (N = 434) in 31 Los Angeles retail pharmacies.
RESULTS
The response rate was 58%. Only 42% correctly characterized the likely cause of their symptoms, and only 57% correctly characterized the action of the drug. Worse consumer knowledge was associated with nonwhite race, first-time use, and less contact with health providers.
CONCLUSION
Many consumers possess poor knowledge about phenazopyridine, potentially leading to undertreatment, especially in groups with worse access to care.
Topics: Anesthetics, Local; Cross-Sectional Studies; Female; Health Knowledge, Attitudes, Practice; Humans; Male; Nonprescription Drugs; Outcome Assessment, Health Care; Pain; Phenazopyridine; Urologic Diseases
PubMed: 15209201
DOI: 10.1370/afm.61 -
Journal of the American Veterinary... Aug 1976Severe illness developed after the oral administration of several drugs, including large doses of phenazopyridine (100 mg TID for 4 days) to a cat with dysuria and...
Severe illness developed after the oral administration of several drugs, including large doses of phenazopyridine (100 mg TID for 4 days) to a cat with dysuria and hematuria. Hemolysis and icterus were evident in blood serum and plasma after day 4 of drug administration, and many hemolyzed red blood cell "ghosts" containing Heinz bodies were observed on a stained blood smear. The cat became anemic and died within 48 hours after the last dose was administered. In an attempt to confirm a cause-and-effect relationship between drug administration and disease, 100 mg of phenazopyridine was given TID (65 mg/kg/day) for 3 days to a clinically normal cat. Nearly 50% of the hemoglobin was oxidized to methemoglobin during the course of phenazopyridine administration. Lower dosages of phenazopyridine (10 and 20 mg/kg/day) for longer periods of administration to 2 other clinically normal cats did not result in illness or anemia; however, the number and size of Heinz bodies and blood methemoglobin content were increased. Evidence of hepatic injury was observed in the clinically affected cat and in 2 of the experimental cats. The relationship between hepatic injury and toxic signs was not determined. Combination products recommeneded for treatment of cystitis in man often contain phenazopyridine. Such products should be avoided in cats unless a safe, effective dosage for phenazopyridine can be established.
Topics: Anemia, Hemolytic; Animals; Cat Diseases; Cats; Female; Heinz Bodies; Hematocrit; Jaundice; Male; Methemoglobinemia; Phenazopyridine; Pyridines; Reticulocytes
PubMed: 956020
DOI: No ID Found -
Spectrochimica Acta. Part A, Molecular... Oct 2020Three univariate and two multivariate spectrophotometric methods were developed and subsequently validated to determine phenazopyridine HCl (PHZ) and trimethoprim (TMP)...
Simultaneous determination of phenazopyridine HCl and trimethoprim in presence of phenazopyridine HCl impurity by univariate and multivariate spectrophotometric methods - Quantification of phenazopyridine HCl impurity by univariate methods.
Three univariate and two multivariate spectrophotometric methods were developed and subsequently validated to determine phenazopyridine HCl (PHZ) and trimethoprim (TMP) in the presence of 2,6-Diaminopyridine (2,6-DAP). The first univariate method depends on direct determination of phenazopyridine by measuring its absorbance at 412 nm and performed in concentration range of 1.00-10.00 μg/mL. Then the contribution of phenazopyridine is removed by dividing the mixture spectrum with PHZ divisor (5 μg/mL) after that the constant is mathematically subtracted and finally the generated spectrum is multiplied with the PHZ divisor. These steps eliminate PHZ contribution and the recovered spectrum is that of TMP and 2,6-DAP only where different methods can be applied to determine TMP and 2,6-DAP through this binary mixture spectrum. The first method to determine both components depends on measuring both TMP and 2,6-DAP through their first derivative (DD) spectra at 244.70 and 259.60 nm for TMP and 2,6-DAP, respectively with concentration ranges of 4.00-24.00 μg/mL TMP and 4.00-26.00 μg/mL 2,6-DAP. The second method depends on application of the isoabsorptive method which was used for TMP determination at its isoabsorptive point with 2,6-DAP at 242.64 nm with concentration range 1.00-20.00 μg/mL for TMP. The developed univariate methods were successfully applied to determine PHZ, TMP and PHZ impurity (2,6-DAP). Two multivariate methods were applied for determination of PHZ and TMP in presence of 2,6-DAP namely, Principle Component Regression (PCR) and Partial Least Squares (PLS). The results of the two models show that simultaneous determination of PHZ and TMP in presence of PHZ impurity can be performed in the concentration ranges of 6.00-14.00 μg/mL PHZ and 24.00-56.00 μg/mL TMP. All the proposed methods were successfully applied to analyze PHZ and TMP in pharmaceutical formulations without interference from the dosage form additives and the results were statistically compared with the reported method.
Topics: Least-Squares Analysis; Phenazopyridine; Spectrophotometry; Trimethoprim
PubMed: 32492634
DOI: 10.1016/j.saa.2020.118516