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%).

Efficacy of methenamine with methylthioninium in the treatment of dysuria: a randomized clinical study.

INTRODUCTION AND HYPOTHESIS: Dysuria is a common symptom present in several urological and gynecological conditions. Management relies on the underlying disease but may require additional symptomatic treatment. This study evaluated the combination of methenamine 250 mg and methylthioninium chloride 20 mg in the treatment of dysuria versus phenazopyridine. METHODS: This was a multicenter, single-blind, randomized, superiority clinical trial, including individuals over 18 with dysuria and a score ≥ 5 points on the pre-treatment categorical scale for pain. The primary outcome was the proportion of participants presenting excellent clinical response within 24 h after treatment. Improvement up to 72 h, time to reach improvement, sustained healing, investigators' opinion, and safety were also evaluated. RESULTS: Three hundred and fifteen participants were evaluated. Demographic characteristics and symptoms of dysuria were comparable between groups at baseline. The difference in the excellent response rate between treatments within 24 h was 12.7% (95% CI 6.16, 19.21) for pain, 9.4% (95% CI 3.32, 15.39) for burning, and 12.7% (95% CI 6.37, 18.99) for burning on urination, all in favor of the test drug, which was also superior from 36 to 48 h. Treatments were similar concerning time to reach the absence of symptoms and in the percentage of participants with sustained healing after 72 h. CONCLUSIONS: The association of methenamine with methylthioninium is superior to phenazopyridine in the treatment of dysuria.

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 ...

Intoxicação por fenazopiridina em felino: relato de caso / Phenazopyridine Administration in a Feline Patient: Case Report

Este trabalho tem como objetivo descrever um caso de intoxicação por fenazopiridina, rotineiramente utilizado como anti-sépticos de vias urinárias em humanos, em um felino. O animal apresentou sinais de metemoglobinemia, que incluíam taquipinéia, cianose das mucosas e depressão quatro dias após o início da terapia com o medicamento em questão. O diagnóstico foi confirmado através da análise hematológica, que evidenciou a coloração amarronzada e presença de corpúsculos de Heinz no sangue do animal(AU)

Drugs commonly used as urinary analgesic and antiseptics in human patients are not indicated in cats with lower urinary tract diseases. They mat cause erythrocyes oxidative injury, methemoglobinemia and Heinz body anemia. The reported case describes clinical signs and treatment in a female Siamese vat presented with anemia, cyanosis and tachypnea after five days of phenazopyridine therapy(AU)

Intoxicação por fenazopiridina em felino: relato de caso / Phenazopyridine Administration in a Feline Patient: Case Report

Este trabalho tem como objetivo descrever um caso de intoxicação por fenazopiridina, rotineiramente utilizado como anti-sépticos de vias urinárias em humanos, em um felino. O animal apresentou sinais de metemoglobinemia, que incluíam taquipinéia, cianose das mucosas e depressão quatro dias após o início da terapia com o medicamento em questão. O diagnóstico foi confirmado através da análise hematológica, que evidenciou a coloração amarronzada e presença de corpúsculos de Heinz no sangue do animal

Drugs commonly used as urinary analgesic and antiseptics in human patients are not indicated in cats with lower urinary tract diseases. They mat cause erythrocyes oxidative injury, methemoglobinemia and Heinz body anemia. The reported case describes clinical signs and treatment in a female Siamese vat presented with anemia, cyanosis and tachypnea after five days of phenazopyridine therapy

Ciprofloxacin bioavailability is enhanced by oral co-administration with phenazopyridine: a pharmacokinetic study in a Mexican population.

BACKGROUND: and objective: In Mexico, urinary tract infections (UTIs) constitute the second most frequent type of infections treated at primary-care clinics. Ciprofloxacin has played a major role in the treatment of UTIs because it has a broad spectrum of antibacterial activity. In addition to antimicrobial agents, phenazopyridine has been used to alleviate symptoms that occur during episodes of UTI. Thus, the present study was designed to compare the pharmacokinetic behaviour of ciprofloxacin administered alone versus ciprofloxacin combined with phenazopyridine. PATIENTS AND METHODS: Twenty-four healthy male Mexican volunteers participated in this project. The study was carried out with a single oral dose of ciprofloxacin 500mg. The double-blind, crossover, randomised, balanced trial design comprised two treatments, two periods and two sequences. After administration of the study medication, serial blood samples were collected for a period of 12 hours. The harvested plasma was analysed for ciprofloxacin by high-performance liquid chromatography. The area under the concentration-time curve to last measurable concentration (AUC(t)), area under the concentration-time curve extrapolated to infinity (AUC(infinity)), peak plasma concentration (C(max)), time to reach C(max) (t(max)), mean residence time (MRT), elimination constant (k(e)) and elimination half-life (t(1/2)) were determined from plasma concentrations of both treatments and considered as primary variables for statistical analysis. RESULTS: While there were no differences between the two treatments in terms of C(max) and k(e), AUC(t )and AUC(infinity) were 35% and 29% higher, respectively, in the combined treatment arm. Moreover, a significant delay in t(max )(from 1 to 1.5 hours) and a statistical increase of 29% in MRT were also observed with phenazopyridine co-administration. CONCLUSION: Oral co-administration of phenazopyridine increases ciprofloxacin bioavailability with regard to the amount absorbed (AUC) and permanence in the body (MRT), which could be useful during treatment.

[Acute renal failure caused by phenazopyridine]. / Falla renal aguda por fenazopiridina.

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.

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