Removal of phenazopyridine from water, synthetic urine, and real sample by adsorption using graphene oxide: A DFT theoretical/experimental approach.

Herein, graphene oxide was used as the highly efficient phenazopyridine adsorbent from aqueous medium, synthetic, and human urine. The nanoadsorbent was characterized by different instrumental techniques. The adsorption capacity (1253.17 mg g-1) was reached at pH 5.0, using an adsorbent dosage of 0.125 g L-1 at 298 K. The Sips and Langmuir described the equilibrium data well. At the same time, the pseudo-second order was more suitable for fitting the kinetic data. Thermodynamic parameters revealed the exothermic nature of adsorption with an increase in randomness at the solid-liquid interface. The magnitude of the enthalpy variation value indicates that the process involves the physisorption phenomenon. At the same time, ab initio molecular dynamics data corroborated with the thermodynamic results, indicating that adsorbent and adsorbate establish hydrogen bonds through the amine groups (adsorbate) and hydroxyl groups on the adsorbent surface (weak interactions). Electrostatic interactions are also involved. Additionally, the adsorption assays conducted in simulated medium and human urine showed the excellent performance of adsorbent material to remove the drug in real concentrations excreted by the kidneys (removal values higher than 60%).

Case of drug-induced kidney stone from overuse of phenazopyridine.

Drug-induced nephrolithiasis represents only 1%-2% of stone cases. Here we focus on drugs capable of crystallizing and forming stone, specifically phenazopyridine (Pyridium/Azo). This is a case of a patient who presented with a stone conglomerate in the right proximal ureter and underwent definitive treatment. Interestingly, the stone had a purple hue with FTIR spectroscopy showing stone composition of calcium oxalate (monohydrate and dihydrate) and a material resembling phenazopyridine. We retrospectively learned that she used multiple extended courses of phenazopyridine over 3 months.

Cost Analysis of Oral Phenazopyridine vs Intravesical Lidocaine for Preprocedural Analgesia for Intradetrusor OnabotulinumtoxinA Injections.

INTRODUCTION: Office administration of intradetrusor onabotulinumtoxinA is commonly used to treat overactive bladder. For preprocedure analgesia, either 50 mL 2% intravesical lidocaine instillation for 20 to 30 minutes or 200 mg oral phenazopyridine can be used. Phenazopyridine is associated with shorter appointment times and is noninferior to lidocaine for pain control in this setting. We performed a cost analysis of phenazopyridine vs lidocaine for analgesia before office intradetrusor onabotulinumtoxinA injection for the treatment of idiopathic overactive bladder. METHODS: A health care sector-perspective cost analysis was performed. The following assumptions were made: (1) similar efficacy of each medication in providing adequate analgesia, (2) similar physician ease of performing the procedure with either analgesic, and (3) similar patient satisfaction with either analgesic. Average cost of medications, adverse reactions, nursing tasks, and office visit time were found in publicly available data. Sensitivity analyses were performed using TreeAge Pro 2021, R1 software. RESULTS: Phenazopyridine is less costly compared to lidocaine per visit for office intradetrusor onabotulinumtoxinA injection ($827 vs $925). A difference of $98 per procedure provides a total annual cost savings of over $24 million if all procedures are performed with phenazopyridine instead of lidocaine. Sensitivity analysis showed that phenazopyridine remained less costly under most circumstances, and threshold analysis provided exact circumstances under which phenazopyridine is no longer cost saving. CONCLUSIONS: Phenazopyridine provides cost savings compared to lidocaine for analgesia before office intradetrusor onabotulinumtoxinA injection for the treatment of idiopathic overactive bladder. If adopted by providers nationwide, phenazopyridine may reduce health care spending and minimize office visit time while maintaining patient pain control and satisfaction.

Estudio de utilización de fenazopiridina en la atención médica ambulatoria en la seguridad social / Phenazopyridine: A drug utilization research in the Costa Rican Social Security

Justificación: fenazopiridina es un medicamento analgésico urinario oral; cuenta con una amplia experiencia histórica de uso y, bajo el paradigma de medicina basada en evidencia, tiene poco fundamento de alta calidad para sustentar su valor terapéutico. Objetivo: analizar el perfil de la utilización de la fenazopiridina en la práctica clínica habitual dentro de la Seguridad Social, a nivel de consulta ambulatoria, en los tres niveles de atención y por un periodo de 30 días. Procedimientos: en enero de 2011, en una unidad de cada nivel de atención: Área de Salud de Santa Bárbara, Clínica Dr. Carlos Durán y Hospital Dr. Calderón Guardia, se analizó el reporte de despacho por farmacia de la fenazopiridina, con el fin de preparar un perfil cuantitativo. En el análisis cualitativo de la prescripción, se revisó una muestra al azar de 30 expedientes de pacientes atendidos durante ese periodo en cada unidad, con un formulario prediseñado para el efecto. Resultados: durante 1 mes, tres unidades despacharon 381 prescripciones a los pacientes, mayormente mujeres. La prescripción varió entre 3 y 90 tabletas; la mayoría (60,43%) con solo 10 tabletas para tratamiento. Se documentó la anotación del medicamento y la dosis en un 54,55% de los expedientes. La dosis diaria prescrita (DDP) fue 100 mg TID, equivalente a 300 mg/d, en la mitad de los pacientes, y en las unidades del primer y segundo nivel de atención; seguida de 100 mg BID (33,33%). Un 54,55% de los pacientes tenían diagnóstico de infección del tracto urinario (89% mujeres); de estos, un 89,89% recibió también antibióticos. La duración varió entre 1 y 30 días, y se prolongó más en unidades del segundo y tercer nivel. Conclusión: la utilización es parcial y razonablemente adecuada, apoya el supuesto de efectividad seguridad, sobre todo en el contexto de la atención médica en el primero y segundo niveles de atención. La diversidad en los hábitos de prescripción requiere mejorar su empleo y desarrollar ...

Background: Phenazopiridine is an oral urinary tract analgesic; an extensive historical experience of use and, under the paradigm of evidence-based medicine, its therapeutic value is not supported by high quality explanations. Aim: To analyze the use of phenazopiridine in everyday clinical practice, at an ambulatory level, in the three different levels of attention in the Costa Rican social security during a period of 30 days. Methods: In January 2011, electronic pharmacy records from a first, second and third level health center; Health Area of Santa Barbara, Dr. Carlos Durán Clinic and Dr. Calderón Guardia Hospital, respectively, were obtained to establish the quantitative characteristics of the prescription of phenazopiridine. For the qualitative analysis of the prescription, a random sample of 30 medical records of patients treated during that period in each unit was considered using an instrument previously designed for said task. Results: During one month, three study units prescribed phenazopiridine to 381 patients, mostly females. Prescription varied from 3 to 90 tablets; most patients (60.43%) received only 10 tablets for their treatment regime. In 54.55% of the medical records, the diagnosis and prescription was documented. The daily-prescribed dose (DPD) was 100mg thrice a day, equivalent to 300mg per day in half of the patients; and in the first and second level of attention followed by 100mg twice a day (33.3%). A total of 55.4% of the patients had been diagnosed with urinary tract infection (89% female); of these an 89.9% received also antibiotic treatment. The duration of treatment varied between 1 to 30 days, with more prolonged use in the second and third level of attention. Conclusion: The use of phenazopiridine is partial and reasonably adequate, thus supporting the efficacy-safety criteria in the context of first and second level attention centers. The diversity in the prescription patterns requires improvement in ...

A Randomized, Prospective, Placebo/Controlled Study for the Effect of Phenazopyridine HCl on Pain Perception following Cystoscopy / 대한비뇨기과학회지

PURPOSE: This study was designed to evaluate the analgesic effect, the side effects and the safety of using phenazopyridine HCl after cystoscopy, which is a drug that exerts a topical analgesic effect on the mucosa of the urinary tract. MATERIALS AND METHODS: The 63 patients who underwent cystoscopy at Pusan National University of Hospital from May 2004 to March 2005 were assigned to one of two groups (the experimental group had 35 patients and the control group had 30 patients). The experimental group was administrated antibiotics and phenazopyridine 200mg tid for 4 days and the control group was administrated antibiotics and digestives tid for 4 days. The analgesic effects were assessed with using the Numeric Pain Intensity Scale (NPIS) and the 4-point Categorical scale (CAT). RESULTS: The mean age of the phenazopyridine and control groups were 62.5+/-8.5 and 60.4+/-10.4 years, respectively, and follow-up period was 7 days. The amount of pain gradually decreased from the day 1 to day 7. The score of the NPIS in the experimental group was less than that of the control group, especially on day 1 and 2 after cystoscopy (p<0.05). The score of the CAT in the experimental group was less than that in the control group, especially on day 1 after cystoscopy (p<0.05). At for the degree of pain for consecutive cystoscopy in the same patients, 22 patients (84.7%) answered it was less painful, 3 (11.5%) answered it was the same as before and 1 (3.8%) answered it was more painful in the experimental group; 2 patient (8.7%) said it was less painful, 19 (82.6%) said it was the same as before and 2 (8.7%) said it was more painful in the control group. Side effects were not observed in all cases. CONCLUSIONS: We conclude that phenazopyridine HCl is effective for early acute pain relief following cystoscopy without side effects, and it is safe when used in combination with antibiotics.

Application of stochastic resonance to quantitative analysis of weak chromatographic signal of phenazopyridine in human plasma / 药学学报

<p><b>AIM</b>To apply stochastic resonance algorithm (SRA) to quantitative analysis of weak chromatographic signal, which was embedded in the noise.</p><p><b>METHODS</b>Based on the theory of stochastic resonance (SR), a simple and effective SRA has been established to improve analytical detection limits of chromatographic analysis, which apply to enhance the signal to noise ratio by the optimization of the parameters and Runge-Kutta method, was established. The method was used to quantitative analysis of phenazopyridine in human plasma by HPLC/UV. Meanwhile this method is compared with HPLC/MS.</p><p><b>RESULTS</b>By experimental chromatographic data sets, an excellent quantitative relationship between concentrations of phenazopyridine and their responses had been obtained. The concentration of phenazopyridine in plasma determined by HPLC/UV with SRA and HPLC/MS showed that there was no significant difference (P > 0.05) between the two methods.</p><p><b>CONCLUSION</b>The new method was feasible.</p>

Falla renal aguda por fenazopiridina / Acute renal failure caused by phenazopyridine

A 27 years old woman was admitted due to abdominal cramps, jaundice and oligoanuria, starting 48 hours after eating Chinese food. Hepatic biochemical tests, abdominal ultrasound and retrograde pyelography were normal. The urine was intensely orange colored and microscopic analysis was normal. The serum creatinine and urea nitrogen on admission were 4.59 and 42.5 mg/dl and rose to 13.5 and 72.4 mg/dl, respectively, at the 6th hospital day. Oliguria lasted only 48 hours. Dialysis was not used, since the patient was in good general condition and uremic symptoms were absent. On the 7th day, azotemia began to subside and at the 14th day, serum creatinine was 1.0 mg/dl. Before hospital discharge, she confessed the ingestion of 2.000 mg of phenazopyridine, during a nervous breakdown, aiming to sleep deeply. Remarkable was the persistence of the orange color of her urine during several days and the dissociation between the rate of increase of serum creatinine with respect to urea nitrogen. This is an unusual case of acute renal failure caused by an overdose of a drug, commonly prescribed for urinary tract infections.

Estudo comparativo entre a associaçäo sulfametoxazol-trimetoprim-fenilazopiridina (Uro Bactrim F) e o norfloxacin no tratamento de infecçöes urinárias agudas / Comparative study between the association of sulfamethoxazole-trimethoprim-phenazopyridine (Uro Bactrim F) and norfloxacin in the treatment of urinary tract infections

Foram selecionados para um estudo aberto, paralelo, comparativo e randomizado 40 pacientes portadores de infecçöes agudas do trato urinário inferior. Cada grupo foi composto de 20 pacientes sendo o primeiro tratado com a associaçäo sulfametoxazol-trimetoprim-fenilazopiridina (Uro Bactrim FR) e o segundo com norfloxacin. O objeto principal deste estudo foi o de avaliarmos o tempo necessário para analgesia com a fenilazopiridina, um dos componentes ativos do Uro Bactrim FR, assim como avaliarmos a eficácia e tolerância de ambos os tratamentos. As avaliaçöes clínicas foram realizadas diariamente, durante os cinco primeiros dias e no final do tratamento (10§ dia). O exame simples de urina assim como cultura e antibiograma foram realizados antes e no 3§ ou 5§ dias após o tratamento. A urinocultura prévia do tratamento revelou 17 casos de E. coli, um caso de P. mirabilis, um caso de S. epidermidis e um caso de S. faecalis no primeiro grupo; no grupo tratado com norfloxacin, observou-se 10 casos de E. coli, dois casos de S. faecalis, um caso de S. aureus, seis casos de Proteus sp. e um caso de Enterobacter. Todos os pacientes obtiveram negativaçäo bacteriológica após o tratamento. O estudo estatístico dos parâmetros clínicos demonstrou diferença estatisticamente significativa nos parâmetros referentes a estrangúria e disúria em favor do grupo tratado com a associaçäo sulfametoxazol-trimetoprim-fenilazopiridina. Conclui-se que o menor tempo necessário para analgesia, aliado à boa eficácia e tolerância da associaçäo sulfametoxazol-trimetoprim-fenilazopiridina indicam esse medicamento como uma boa opçäo terapêutica para o tratamento de infecçöes urinárias agudas