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.

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.

Oral phenazopyridine vs intravesical lidocaine for bladder onabotulinumtoxinA analgesia: a randomized controlled trial.

BACKGROUND: The efficacy of intradetrusor onabotulinumtoxinA injections for the management of idiopathic overactive bladder has been well-established. The injections are typically performed in the office setting using local analgesia, most commonly a 20 to 30-minute intravesical instillation of lidocaine. There are limited data evaluating alternative bladder analgesics. OBJECTIVE: To compare pain scores with preprocedure oral phenazopyridine vs intravesical lidocaine in women undergoing intradetrusor onabotulinumtoxinA injections for idiopathic overactive bladder. STUDY DESIGN: Nonpregnant adult females with idiopathic overactive bladder, scheduled for office injection of 100 units of intradetrusor onabotulinumtoxinA were randomized to either 200 mg of oral phenazopyridine taken 1 to 2 hours preprocedure or a 20-minute preprocedure intravesical instillation of 50 mL of 2% lidocaine. We excluded participants with neurogenic bladders, and those who had received intradetrusor onabotulinumtoxinA injections in the previous 12 months. The primary outcome was pain measured by a 100-mm visual analog scale. Demographic characteristics and overall satisfaction with the procedure were also recorded. Providers answered questions about cystoscopic visualization, ease of procedure, and perception of participant comfort. Prespecified noninferiority margin was set to equal the anticipated minimum clinically important difference of 14 mm. A planned sample of 100 participants, 50 in each treatment arm, provided 80% power to detect noninferiority at a significance level of.05. We performed a modified intention-to-treat analysis and compared variables with the t test or the Fisher exact test. RESULTS: A total of 111 participants were enrolled, and complete data were obtained for 100 participants; 47 participants were randomized to phenazopyridine and 53 to lidocaine. Baseline characteristics did not differ between groups. There were 19.6% and 20.8% of participants in the phenazopyridine and lidocaine groups, respectively, who previously underwent intradetrusor onabotulinumtoxinA injections. The mean postprocedure pain was 2.7 mm lower in the phenazopyridine group than in the lidocaine group (95% confidence interval, -11.3 to 10.7), demonstrating noninferiority. More than 90% of participants in both groups stated that the pain was tolerable. Slightly more participants reported being "very satisfied" in the lidocaine group, although this was not statistically significant (50.0% vs 40.4%; P=.34). Providers reported clear visualization in 89.4% of participants in the phenazopyridine group and in 100% of participants in the lidocaine group (P=.02). Provider perception of participant comfort and overall ease of procedure were not different between groups. Length of time in the exam room was significantly shorter in the phenazopyridine than in the lidocaine group (44.4 vs 57.5 minutes; P=.0003). CONCLUSION: In women receiving intradetrusor onabotulinumtoxinA injections for idiopathic overactive bladder, oral phenazopyridine was noninferior to intravesical lidocaine for procedural pain control. Phenazopyridine is well-tolerated by participants, allows for the procedure to be performed with similar ease, and is associated with shorter appointment times.

Cost-effectiveness of agents used for evaluation of ureteral patency during intraoperative cystoscopy in gynecologic and urogynecologic surgery.

BACKGROUND: Intraoperative evaluation of ureteral patency is often performed in gynecologic and urogynecologic surgery. Many agents are used to help assess the patency, each with its own associated cost, ease of use, and adverse reactions. Some agents, such as dextrose, are used as an instillation fluid to create a viscosity difference and aid the visualization of a ureteral jet. Others, such as oral phenazopyridine or the intravenous use of sodium fluorescein and indigo carmine, cause a color change of the urine to directly aid the visualization of ureteral jets. Recently, numerous studies have examined the efficacy and surgeon satisfaction of these agents. The studies have also emphasized certain options as associated with a lower cost. However, there have not been any cost studies comparing these agents. OBJECTIVE: To compare the cost-effectiveness of the following 4 agents that are commonly used in assessing ureteral patency intraoperatively: oral phenazopyridine, dextrose instillation, intravenous sodium fluorescein, and intravenous indigo carmine. STUDY DESIGN: We constructed a decision-analytic model to compare cystoscopy using oral phenazopyridine, dextrose instillation, intravenous sodium fluorescein, and intravenous indigo carmine. Failure to see efflux resulted in work-ups for ureteral obstruction. The probabilities were obtained from published studies, and the probability of successfully seeing efflux ranged from 0.92 with oral phenazopyridine to 0.99 with intravenous indigo carmine. The costs of the agents, adverse effects, and ureteral obstruction work-ups were obtained from the University of North Carolina at Chapel Hill Department of Pharmacy, the Healthcare Cost and Utilization Project 2016 database and the FAIR Health Consumer database. The cost of a ureteral obstruction work-up used in our model ranged from $9755 for intraoperative evaluation with retrograde pyelograms and stents to $29,034 for hospitalization. Our primary outcome was the incremental cost-effectiveness ratio per unnecessary work-up for ureteral obstruction avoided. Sensitivity analyses were performed to identify the key uncertainties. RESULTS: Oral phenazopyridine, followed by an intravenous agent if needed, had a mean cost of $110 per patient. Dextrose averaged $151 more per patient, with only a slight improvement in avoiding unnecessary ureteral obstruction work-ups and a higher cost associated with adverse reactions (incremental cost-effectiveness ratio, $62,000). Intravenous agents cost approximately $1000 more per patient and were less effective at preventing unnecessary work-ups. Sensitivity analyses did not identify any thresholds that would significantly change the outcomes. CONCLUSION: Our model suggests that oral phenazopyridine and dextrose instillation are the least expensive and the most effective agents to aid in the visualization of ureteral patency during intraoperative cystoscopy, although dextrose is associated with higher costs owing to a higher rate of adverse reactions (primarily urinary tract infections). Intravenous sodium fluorescein and indigo carmine are historically popular first-choice agents. However, they were found to be more expensive and less effective as primary agents in our model and should likely be reserved for use as secondary agents in the event that the visualization of ureteral jets is unclear with the initial use of phenazopyridine or dextrose.

The effect of preoperative phenazopyridine on short-term urinary retention following urogynecologic surgery.

INTRODUCTION AND HYPOTHESIS: Previous studies have found that administration of phenazopyridine decreased short-term urinary retention following surgery but other more recent trials have shown mixed results. This study sought to investigate the potential benefit of preoperative administration of oral phenazopyridine in relation to the prevention of short-term urinary retention following urogynecologic surgery. METHODS: This is a retrospective cohort study of a convenience sample of women undergoing urogynecologic surgery from June 2016 to March 2019. Following surgery, subjects underwent a standardized retrograde voiding trial. The data had previously been gathered from a prior prospective trial at our institution (Kesty et al. Int Urogynecol J 31(9):1899-1905, 11). Chart review was performed to determine whether patients that received 200 mg of preoperative oral phenazopyridine to better visualize ureteral efflux during cystourethroscopy were more or less likely to pass their postoperative voiding trial. Bivariate statistical analysis was performed as well as a multivariate logistic regression model. RESULTS: A total of 165 subjects were included in the final analysis; 100 who did not receive preoperative phenazopyridine and 65 who did receive phenazopyridine. There was no statistical difference between voiding trial pass rates following urogynecologic surgery between those who did not receive preoperative phenazopyridine compared to those who did [77% (77/100) and 82% (53/65), respectively, p = 0.37)]. The multivariate logistic regression model demonstrated no difference in postoperative voiding trial pass rates among those who received preoperative phenazopyridine compared to those who did not (OR 1.7, 95% CI: 0.53, 5.8). CONCLUSIONS: Preoperative administration of oral phenazopyridine does not decrease short-term urinary retention following urogynecologic surgery.

Urine staining intensity and observation of intraoperative ureteral jets among oral agents.

INTRODUCTION AND HYPOTHESIS: To determine if administration of a standard 400 mg oral dose of riboflavin (vitamin B2) was comparable to phenazopyridine (pyridium) for evaluating ease of visualization of ureteral jets at the time of cystoscopy. METHODS: A three-arm double-blinded, randomized controlled study was performed consisting of thiamine as placebo, phenazopyridine, and riboflavin. Agents were administered the morning of surgery prior to surgical procedure. The primary outcome was the ease of visualization of the ureteral jets based on a grading of urine stain intensity on a 7-point color scale, where 1-2 were minimal yellow staining, 3-4 were moderate yellow staining, and 5-7 defined as intense yellow staining. Analysis of covariance (ANCOVA) was used with pairwise comparison to characterize urine stain intensity as a continuous variable among the three groups controlling for age, BMI, creatinine, and time from ingestion of medication to first cystoscopy. RESULTS: Eighty-four subjects were randomized with a mean ± SD age of 46.25 + 11.36 and BMI of 32.46 + 6.59. Riboflavin did have moderate or intense staining in 57% of cases; however, there was no significant difference between urine staining intensity compared to placebo (p = 0.21). There was a statistically significant increased urine staining intensity for phenazopyridine compared to placebo (p = 0.001) and for phenazopyridine compared to riboflavin (p = 0.001). CONCLUSIONS: Phenazopyridine provided statistically significantly greater urine staining compared to both riboflavin and placebo and should be considered primarily for ease of ureteral jet visualization.

Skin ulcers as a complication of short-term use of phenazopyridine in an old man: A case report.

INTRODUCTION: Phenazopyridine is an azo dye, which exerts local anesthetic or analgesic action on urinary tract mucosa through an unknown mechanism. Besides its common complications including orange discoloration of the urine and gastrointestinal problems, it may have rare side effects like hemolytic anaemia, methemoglobinemia, renal failure, and skin changes. We reported a paraplegic man with skin ulcers on scretom and right foot after about 3 days of phenazopyridine use CASE REPORT: A 62-year-old man presented with flesh shaped deep ulcers in lower parts of the body. He declared that at first a bluish discoloration was developed in the lower extremities and scrotum skin after use of eight phenazopyridine tablets (200 mg) and then these lesions turned to blisters and ulcers and they were prurient. The patient underwent sonography and CT-angiography; however, no pathologic findings were found. He just received losartan for many years as past drug history. According to the history, a delayed drug hypersensitivity reaction was suspected and the patient wounds healed after using special type of dressings and antibiotic therapy regarding positive wound cultures. CONCLUSION: Phenazopyridine severe skin changes are hardly reported. We described a case who experienced severe skin reactions and ulcers following phenazopyridine use not related to other complications including renal dysfunction, methemoglobinemia, and hemolytic anemia.

ROS/JNK-mediated lysosomal injury in rat intestinal epithelial-6 cells during heat stress.

Injury to the intestinal epithelial cells and loss of the intestinal barrier are critical to heatstroke. To reveal the mechanism through which heatstroke leads to intestinal epithelial injury, the relationship between reactive oxygen species (ROS), c-Jun NH2-terminal kinase (JNK), and lysosomes were studied in intestinal epithelial cells subjected to heat stress. Cells of heat stress groups were incubated at 43 °C for 1 h, then incubated at 37 °C as indicated. Control group cells were incubated at 37 °C. Cell-counting kit-8 assay was used to assess cell viability. Cells were labeled with 2'-7'dichlorofluorescin diacetate and acridine orange (AO) staining, respectively, the total ROS and AO were detected by confocal laser scanning microscopy and flow cytometry. Apoptosis was analyzed by flow cytometry using annexin V-fluorescein isothiocyanate/prodium iodide staining, the expressions of mitogen-activated protein kinases were detected by western blotting. Heat stress induced apoptosis and inhibited cell viability, the production of ROS, and lysosomal injury in IEC-6 cells. After pretreatment with the lysosomal cathepsin inhibitor E64, the JNK inhibitor SP600125, or the ROS scavenger NAC, the effect of heat stress on apoptosis or lysosomal injury was significantly attenuated. In conclusion, heat stress induced apoptosis, lysosomal injury, and the accumulation of ROS in IEC-6 cells; mechanistically, this occurred through the ROS-induced activation of JNK signaling, which mediated the lysosomal injury and ultimately apoptosis.

Case Report: Phenazopyridine-Induced Sulfhemoglobinemia in an 83-Year-Old Presenting with Dyspnea.

BACKGROUND: Sulfhemoglobinemia is a rare dyshemoglobinemia that presents similarly to methemoglobinemia. CASE REPORT: An 83-year-old woman with stage IV ovarian cancer presented to the Emergency Department after a near syncopal spell and was found to be cyanotic with a pulse oximetry reading of 71%. Pulse oximetry improved to only the mid-80s range with administration of high-flow oxygen. Her arterial blood gas on supplemental high-flow oxygen demonstrated a PaO2 of 413 mm Hg and methemoglobin of 1.2%, but also noted the interference of the co-oximetry with sulfhemoglobinemia. Further history revealed that the patient had recently been started on phenazopyridine. The phenazopyridine was stopped, an exchange transfusion was offered but declined, and the patient was discharged to home hospice. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The diagnosis of sulfhemoglobinemia can be challenging given that routine co-oximetry does not identify it. The clue to the diagnosis is that the cyanotic-appearing patient has a normal or elevated PaO2 and seems to be less ill than expected, given the degree of cyanosis. Sulfhemoglobinemia does not reverse with the administration of methylene blue.

[Phenazopyridine and fosfomycin for the acute cystitis treatment: results of multicenter randomized study].

AIM: To evaluate the analgesic effect, efficacy and tolerability of phenazopyridine in combination with fosfomycin for the treatment of acute uncomplicated cystitis in working-age female. MATERIAL AND METHODS: A total of 152 women with acute uncomplicated cystitis were included in multicenter, randomized, open-label study which were carried out in 5 polyclinics of the Perm Territory. All the patients were divided into 2 groups of 76 people each, depending on the treatment. In the main group, women received oral phenazopyridine 200 mg 3 times a day for 2 days (a total dose 1200 mg) and fosfomycin trometamol in a dose of 3 g once. In the control group, patients received a single dose of fosfomycin trometamol (3 g) and drotaverin 80 mg 3 times a day for 2 days. A visual analogue scale (VAS) was used for evaluation of pain intensity. The symptoms of cystitis were assessed using the ACSS scale. In addition, urinalysis, urine culture and other methods were done. The results were evaluated after 6, 12, 24, 48 hours, 3 and 6 days. RESULTS: In the main group, the severity of pain according to the VAS decreased from the initial 7.2+/-0.5 points to 1.6+/-0.2 points after 12 hours, to 0.4 +/- 0.05 points after 24 hours. Pain syndrome completely disappeared in all patients after 48 hours. In the control group, at all time points, a significant less pronounced analgesic effect was seen (p<0.001). The overall ACSS score in the main group decreased from the 12.0+/-0.5 points to 2.1+/-0.3 after 3 days and to 0.28+/-0.04 points after 6 days (p<0.001), which indicated a more rapid resolution of symptoms compared to the control group. The symptomatic effect of phenazopyridine (relief of pain, dysuria and discomfort) provided a more pronounced improvement in the well-being in the main group in comparison to the control group, which was confirmed by Dynamics domain of the ACSS scale (p<0.001). The combination of fosfomycin and phenazopyridine was more effective than the combination of fosfomycin and drotaverine. The clinical and microbiological cure rate in the main group was 97.4% and 96.9%, respectively. Leukocyturia was resolved earlier, and the duration of treatment decreased by 30.1%. An undesirable effect of phenazopyridine (nausea) was detected only in 1 (1.3%) patient. CONCLUSION: Phenazopyridine has a pronounced analgesic effect and is proved to be an effective and safe drug in patients with acute uncomplicated cystitis.

Quantitative determination of trace phenazopyridine in human urine samples by hyphenation of dispersive solid-phase extraction and liquid-phase microextraction followed by gas chromatography/mass spectrometry analysis.

Magnetic dispersive solid-phase extraction followed by dispersive liquid-liquid microextraction coupled with gas chromatography/mass spectrometry was applied for the quantitative analysis of phenazopyridine in urinary samples. Magnetic dispersive solid-phase extraction was carried out using magnetic graphene oxide nanoparticles modified by poly(thiophene-pyrrole) copolymer. The eluting solvent of this step was used as the disperser solvent for the dispersive liquid-liquid microextraction procedure. To reach the maximum efficiency of the method, effective parameters including sorbent amount, adsorption time, type and volume of disperser and extraction solvents, pH of the sample solution, and ionic strength as well as desorption time, and approach were optimized, separately. Characterization of the synthesized sorbent was studied by utilizing infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray analysis. Calibration curve was linear in the range of 0.5-250 ng/mL (R2  = 0.9988) with limits of detection and quantification of 0.1 and 0.5 ng/mL, respectively. Intra- and interday precisions (RSD%, n = 3) of the method were in the range of 4.6-5.4% and 4.0-5.5%, respectively, at three different concentration levels. Under the optimal condition, this method was successfully applied for the determination of phenazopyridine in human urine samples. The relative recoveries were obtained in the range of 85.0-89.0%.

Safety analysis of long-term phenazopyridine use for radiation cystitis.

BACKGROUND: Phenazopyridine is a urinary tract analgesic indicated for short-term treatment of irritation in the lower urinary tract. Despite the lack of evidence for extended use, it is often used in varying durations for supportive care for cancer patients with radiation-induced cystitis. The objective of this study was to compare the incidence of adverse drug reactions in patients with radiation cystitis receiving long-term phenazopyridine (>14-day supply) compared to a matched comparator group. METHODS: This retrospective cohort study compared adverse events among cancer patients with and without phenazopyridine exposure. Included patients received radiation and at least one chronic medication between 1 July 2008 and 30 June 2017. The phenazopyridine group also received >14-day supply of phenazopyridine during the study period. Patients were matched based on gender, age (±5 years), cancer diagnosis, and palliative or curative treatment intent. Data collection occurred at baseline, during the time of presumed exposure, and through the end of the study period for surveillance purposes. RESULTS: A total of 272 patients received phenazopyridine for >14-day supply during the study period. Of these, 90 patients were included and matched to an equal number of patients in the comparator group. The included patients were similar between groups and were largely male with a diagnosis of prostate cancer. Most patients received between a 30- and 60-day supply of phenazopyridine. There were a total of 13 adverse drug reactions in the phenazopyridine group and 18 in the comparator group (p = 0.32). No differences were identified between the phenazopyridine and comparator groups for the incidence of individual adverse drug reactions, emergency department visits, hospitalizations, or new diagnoses of hepatocellular or colorectal cancer. CONCLUSION: There was no difference in adverse drug reactions among patients receiving phenazopyridine for >14 days compared to a matched comparator group. The overall incidence of adverse events in both groups was low.

Removal of Phenazopyridine from wastewater by merging biological and electrochemical methods via Azolla filiculoides and electro-Fenton process.

In the present study, the potential of Azolla filiculoides (A. filiculoides) was first investigated for degradation of Phenazopyridine (PhP), an analgesic drug. The effects of main variables such as initial pharmaceutical concentration, amount of plant, and pH were studied on the efficiency of the biological process. It was observed that A. filiculoides was able to remove pharmaceuticals from contaminated water up to 85.90% during 48 h. Then, the electro-Fenton (EF) method was applied for further removal of PhP yielding a removal rate of about 98.72% under optimum conditions during 2 h. The effects of variables including the current, amount of catalyst, and pH were also studied in this phase. Also, the probability of adsorption was investigated during this step. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were performed for the used magnetite nanoparticles, total organic carbon (TOC) were performed to investigate PhP removal efficiency during the reaction time and Gas chromatography-mass spectrometry (GC-MS) were performed to analyze degradation byproducts of PhP. Based on the results, it was found that a combination of these bioremediation and electrochemical removal steps were capable of PhP removal from contaminated water. Therefore, this approach may be effective for phytoremediation of pharmaceutical-contaminated aquatic ecosystems.

[Influence of phenazopyridine on the well-being of patients during and after cystoscopy].

INTRODUCTION: Cystoscopy is one of the most common procedures in urology. There is no single approach to pain relief. In the literature, there are conflicting data on the efficiency of intra-urethral gels. The use of non-steroidal anti-inflammatory drugs, intravenous sedation, and nitric oxide analgesia has been described. Phenazopyridine has been known for a long time. Acting on the bladder mucosa, it has a local analgesic effect. AN evaluation of phenazopyridine intake prior to cystoscopy in order to decrease pain during procedure and facilitate subsequent urination was performed. MATERIALS AND METHODS: A total of 97 patients were included in the study. Indications for cystoscopy were as following: hematuria, lower urinary tract symptoms/pain, a need to remove ureteral stent. The patients were randomized into two groups. In the main group (n=50), phenazopyridine 200 mg was administered 20 minutes before cystoscopy and then at a dose of 200 mg every 8 hours (in total three doses) in combination with lidocaine gel. In the control group (n=47), only lidocaine gel was used. Heart rate was measured before and after the procedure. All patients were asked to complete a visual analogue scale (VAS) 3, 8 and 24 hours after cystoscopy with the assessment of the first urination. RESULTS: After cystoscopy, the difference between groups in VAS score was 27.7% in favor of the main group (p<0.001). After 3 hours, the average score in the main group was two times less than in the Control (p=0.012), while 3 and 8 hours after cystoscopy, the proportion of "zero" results was 10% and 0%, 28% and 4%, respectively, p<0.005. The heart rate after the procedure in the main group was 75.1 beats/min, compared to 77.9 beats/min in the control group (p=0.016). CONCLUSION: The intake of phenazopyridine allows to reduce pain intensity during and after cystoscopy and alleviate pain during first urination.

[Efficiency and safety of phenazopyridine for treatment of uncomplicated urinary tract infection: results of multi-center, randomized, placebo-controlled, clinical study].

AIM: to evaluate the efficiency and safety of phenazopyridine for the treatment of patients with uncomplicated lower urinary tract infection, accompanied by pain. MATERIALS AND METHODS: A multicenter double-blind, randomized, placebo-controlled study with parallel groups to evaluate the efficacy and safety of phenazopyridine in patients with acute uncomplicated cystitis was performed. A total of 60 women were divided into two groups of 30 patients. In the main group (average age 32.6+/-7.4 years) phenazopyridine was prescribed (2 tablets of 100 mg p.o., with a total dose of 200 mg, once). In the control group, patients (mean age 35.53+/-8.79 years) received a placebo according to the same scheme. To evaluate the efficiency of treatment, the severity of the main symptoms 6 hours after taking the drug was analyzed. After that, patients started antibiotic therapy. They were followed-up for the next three days. The tolerance of therapy was evaluated by the presence of adverse events. RESULTS: All 30 patients taking phenazopyridine had an improvement after 6 hours, and the most frequent response was "significant improvement" (43.3%). The responses of patients in the main group significantly (p<0.05) differed from responses of patients in the control group. Six hours after taking phenazopyridine/placebo, the severity of all values according to VAS score, including the degree of general discomfort, pain during urination and increased frequency of urination improved significantly in the main group compared to the control group. The average assessment of general discomfort in the main group decreased by 53.4% in comparison with 28.8% in the control group, while the severity of pain during urination and urination frequency decreased by 57.4 vs. 35.9% and 39.6 vs. 27.6%, respectively. An analysis of the time before the complete absence of the general discomfort was performed. In the main group this period of time was significantly less than in the control group (p<0.05). There were no serious adverse events while taking phenazopyridine. Rate of adverse events was comparable between two groups. CONCLUSION: The results of the study showed that phenazopyridine is an effective and well-tolerated drug for symptomatic therapy in patients with acute uncomplicated cystitis and can be recommended in addition to etiological therapy.

Anticancer and antibacterial activity in vitro evaluation of iridium(III) polypyridyl complexes.

Three iridium(III) polypyridyl complexes [Ir(ppy)2(PYTA)](PF6) (1) (ppy = 2-phenylpyridine), [Ir(bzq)2(PYTA)](PF6) (2) (bzq = benzo[h]quinolone) and [Ir(piq)2(PYTA)](PF6) (3) (piq = 1-phenylisoquinoline, PYTA = 2,4-diamino-6-(2'-pyridyl)-1,3,5-triazine) were synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR. The cytotoxic activity of the complexes toward cancer SGC-7901, Eca-109, A549, HeLa, HepG2, BEL-7402 and normal LO2 cell lines was investigated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Complex 3 shows the most effective on inhibiting the above cell growth among these complexes. The complexes locate at the lysosomes and mitochondria. AO/EB, Annex V and PI and comet assays indicate that the complexes can induce apoptosis in SGC-7901 cells. Intracellular ROS and mitochondrial membrane potential were examined under fluorescence microscopy. The results demonstrate that the complexes increase the intracellular ROS levels and induce a decrease in the mitochondrial membrane potential. The complexes can enhance intracellular Ca2+ concentration and cause a release of cytochrome c. The autophagy was studied using MDC staining and western blot. Complexes 1-3 can effectively inhibit the cell invasion with a concentration-dependent manner. Additionally, the complexes target tubules and inhibit the polymerization of tubules. The antimicrobial activity of the complexes against S. aureus, E. coli, Salmonella and L. monocytogenes was explored. The mechanism shows that the complexes induce apoptosis in SGC-7901 cells through ROS-mediated lysosomal-mitochondrial, targeting tubules and damage DNA pathways. Three iridium(III) complexes [Ir(N-C)2(PYTA)](PF6) (N-C = ppy, 1; bzq, 2; piq, 3) were synthesized and characterized. The anticancer activity of the complexes against SGC-7901 cells was studied by apoptosis, comet assay, autophagy, ROS, mitochondrial membrane potential, intracellular Ca2+ levels, release of cytochrome c, tubules and western blot analysis. The antibacterial activity in vitro was also assayed.

A Cell-Free Approach Based on Phospholipid Characterization for Determination of the Cell Specific Unbound Drug Fraction (fu,cell).

PURPOSE: The intracellular fraction of unbound compound (fu,cell) is an important parameter for accurate prediction of drug binding to intracellular targets. fu,cell is the result of a passive distribution process of drug molecules partitioning into cellular structures. Initial observations in our laboratory showed an up to 10-fold difference in the fu,cell of a given drug for different cell types. We hypothesized that these differences could be explained by the phospholipid (PL) composition of the cells, since the PL cell membrane is the major sink of unspecific drug binding. Therefore, we determined the fu,cell of 19 drugs in cell types of different origin. METHOD: The cells were characterized for their total PL content and we used mass spectrometric PL profiling to delineate the impact of each of the four major cellular PL subspecies: phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI). The cell-based experiments were compared to cell-free experiments that used beads covered by PL bilayers consisting of the most abundant PL subspecies. RESULTS: PC was found to give the largest contribution to the drug binding. Improved correlations between the cell-based and cell-free assays were obtained when affinities to all four major PL subspecies were considered. Together, our data indicate that fu,cell is influenced by PL composition of cells. CONCLUSION: We conclude that cellular PL composition varies between cell types and that cell-specific mixtures of PLs can replace cellular assays for determination of fu,cell as a rapid, small-scale assay covering a broad dynamic range. Graphical Abstract.

Approach for Downscaling of Electromembrane Extraction as a Lab on-a-Chip Device Followed by Sensitive Red-Green-Blue Detection.

A design of electromembrane extraction (EME) as a lab on-a-chip device was proposed for the extraction and determination of phenazopyridine as the model analyte. The extraction procedure was accomplished by coupling EME and packing a sorbent. The analyte was extracted under the applied electrical field across a membrane sheet impregnated by nitrophenyl octylether (NPOE) into an acceptor phase. It was followed by the absorption of the analyte on strong cation exchanger as a sorbent. The designed chip contained separate spiral channels for donor and acceptor phases featuring embedded platinum electrodes to enhance extraction efficiency. The selected donor and acceptor phases were 0 mM HCl and 100 mM HCl, respectively. The on-chip electromembrane extraction was carried out under the voltage level of 70 V for 50 min. The analysis was carried out by two modes of a simple red-green-blue (RGB) image analysis tool and a conventional HPLC-UV system. After the absorption of the analyte on the solid phase, its color changed and a digital picture of the sorbent was taken for the RGB analysis. The effective parameters on the performance of the chip device, comprising the EME and solid phase microextraction steps, were distinguished and optimized. The accumulation of the analyte on the solid phase showed excellent sensitivity and a limit of detection (LOD) lower than 1.0 µg L-1 achieved by an image analysis using a smartphone. This device also offered acceptable intra- and interassay RSD% (<10%). The calibration curves were linear within the range of 10-1000 µg L-1 and 30-1000 µg L-1 ( r2 > 0.9969) for HPLC-UV and RGB analysis, respectively. To investigate the applicability of the method in complicated matrixes, urine samples of patients being treated with phenazopyridine were analyzed.

Structural Approach To Identify a Lead Scaffold That Targets the Translesion Synthesis Polymerase Rev1.

Translesion synthesis (TLS) is a mechanism of replication past damaged DNA through which multiple forms of human cancer survive and acquire resistance to first-line genotoxic chemotherapies. As such, TLS is emerging as a promising target for the development of a new class of anticancer agents. The C-terminal domain of the DNA polymerase Rev1 (Rev1-CT) mediates assembly of the functional TLS complex through protein-protein interactions (PPIs) with Rev1 interacting regions (RIRs) of several other TLS DNA polymerases. Utilizing structural knowledge of the Rev1-CT/RIR interface, we have identified the phenazopyridine scaffold as an inhibitor of this essential TLS PPI. We demonstrate direct binding of this scaffold to Rev1-CT, and the synthesis and evaluation of a small series of analogues have provided important structure-activity relationships for further development of this scaffold. Furthermore, we utilized the umbrella sampling method to predict the free energy of binding to Rev1-CT for each of our analogues. Binding energies calculated through umbrella sampling correlated well with experimentally determined IC50 values, validating this computational tool as a viable approach to predict the biological activity for inhibitors of the Rev1-CT/RIR PPI.

Distinct binding of PET ligands PBB3 and AV-1451 to tau fibril strains in neurodegenerative tauopathies.

Diverse neurodegenerative disorders are characterized by deposition of tau fibrils composed of conformers (i.e. strains) unique to each illness. The development of tau imaging agents has enabled visualization of tau lesions in tauopathy patients, but the modes of their binding to different tau strains remain elusive. Here we compared binding of tau positron emission tomography ligands, PBB3 and AV-1451, by fluorescence, autoradiography and homogenate binding assays with homologous and heterologous blockades using tauopathy brain samples. Fluorescence microscopy demonstrated intense labelling of non-ghost and ghost tangles with PBB3 and AV-1451, while dystrophic neurites were more clearly detected by PBB3 in brains of Alzheimer's disease and diffuse neurofibrillary tangles with calcification, characterized by accumulation of all six tau isoforms. Correspondingly, partially distinct distributions of autoradiographic labelling of Alzheimer's disease slices with 11C-PBB3 and 18F-AV-1451 were noted. Neuronal and glial tau lesions comprised of 4-repeat isoforms in brains of progressive supranuclear palsy, corticobasal degeneration and familial tauopathy due to N279K tau mutation and 3-repeat isoforms in brains of Pick's disease and familial tauopathy due to G272V tau mutation were sensitively detected by PBB3 fluorescence in contrast to very weak AV-1451 signals. This was in line with moderate 11C-PBB3 versus faint 18F-AV-1451 autoradiographic labelling of these tissues. Radioligand binding to brain homogenates revealed multiple binding components with differential affinities for 11C-PBB3 and 18F-AV-1451, and higher availability of binding sites on progressive supranuclear palsy tau deposits for 11C-PBB3 than 18F-AV-1451. Our data indicate distinct selectivity of PBB3 compared to AV-1451 for diverse tau fibril strains. This highlights the more robust ability of PBB3 to capture wide-range tau pathologies.