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Antimicrobial Agents and Chemotherapy Jan 1973Phenazopyridine, at its maximum tolerated dose, did not affect the effectiveness of sulfonamides against uropathogenic bacterial species in mice.
Phenazopyridine, at its maximum tolerated dose, did not affect the effectiveness of sulfonamides against uropathogenic bacterial species in mice.
Topics: Anesthetics, Local; Animals; Drug Therapy, Combination; Escherichia coli Infections; Mice; Phenazopyridine; Proteus Infections; Pyridines; Sulfonamides; Urinary Tract Infections
PubMed: 4597706
DOI: 10.1128/AAC.3.1.134 -
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 -
Female Pelvic Medicine & Reconstructive... 2018To determine the effect of preoperative oral phenazopyridine on postoperative voiding dysfunction in women undergoing a retropubic midurethral sling. (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To determine the effect of preoperative oral phenazopyridine on postoperative voiding dysfunction in women undergoing a retropubic midurethral sling.
METHODS
A single-institution randomized clinical trial was performed from September 2015 to March 2017, comparing 200 mg of oral phenazopyridine versus no phenazopyridine in patients undergoing a retropubic midurethral sling under general anesthesia with no concomitant procedures. A power calculation indicated that we required at least 40 subjects per arm. Preoperative demographics, intraoperative medications, blood loss, and complications were recorded. A standardized voiding trial was performed before discharge. Voiding dysfunction was determined by the proportion of subjects who failed a postoperative voiding trial. Pain scores were obtained before and 2 to 3 hours after the surgical procedure. Patient characteristics and surgical data were compared using χ, Fisher exact test, or Wilcoxon rank sum test.
RESULTS
Ninety-two subjects were enrolled in the study. Three patients cancelled their surgery and 1 had an intraoperative urethral injury, leaving 88 patients for the final analysis (44 per arm). Patient demographics showed no differences between groups. Phenazopyridine did not reduce the proportion of patients who failed the voiding trial (27%) compared with subjects who did not receive the medication (21%) (P = 0.453). Postoperative visual analog pain scores were higher in those not receiving phenazopyridine (1.76 vs 1.21, P = 0.046), but after adjusting for the difference in preoperative and postoperative pain scores, the groups showed no difference (P = 0.087).
CONCLUSIONS
Our prospective trial shows that phenazopyridine has no effect on short-term postoperative voiding dysfunction. This condition appears to be multifactorial, and further research is needed.
Topics: Administration, Oral; Anesthesia, General; Anesthetics, Local; Body Mass Index; Female; Humans; Middle Aged; Phenazopyridine; Postoperative Complications; Preoperative Care; Prospective Studies; Suburethral Slings; Treatment Outcome; Urinary Incontinence, Stress; Urinary Retention
PubMed: 29474280
DOI: 10.1097/SPV.0000000000000497 -
Clinical Case Reports Mar 2023Hemorrhagic cystitis is a common complication following the use of cyclophosphamide. Associated dysuria can be painful and there are few good options to relieve pain....
Hemorrhagic cystitis is a common complication following the use of cyclophosphamide. Associated dysuria can be painful and there are few good options to relieve pain. Phenazopyridine has historically been utilized for dysuria and is available over the counter. However, it is associated with hematologic side effects with prolonged use. Here we present a case of a patient who developed Heinz body hemolysis following prolonged administration of phenazopyridine to treat cyclophosphamide-induced hemorrhagic cystitis following hematopoietic stem cell transplant.
PubMed: 36911643
DOI: 10.1002/ccr3.7012 -
BMJ Case Reports Sep 2012Methaemoglobin is an altered state of haemoglobin in which the ferrous ions of haeme are oxidised to the ferric state. This results in increased affinity to the bound...
Methaemoglobin is an altered state of haemoglobin in which the ferrous ions of haeme are oxidised to the ferric state. This results in increased affinity to the bound oxygen and decreasing its availability to tissues. Most cases of methaemoglobinaemia are acquired, resulting from an increased methaemoglobin formation by various exogenous agents. The authors report an elderly patient presenting to the emergency department with a 1-month history of shortness of breath. Around the same time she had started using over-the-counter (OTC) phenazopyridine tablets for urinary symptoms. The patient was hypoxic and cyanotic; however, lacked evidence of hypoxaemia on the arterial blood gas. The presence of abnormal haemoglobin was suspected and confirmed by elevated levels of methaemoglobin. Phenazopyridine was proposed to be the likely aetiology of the methaemoglobinaemia, which the patient was not aware of. This case highlights the importance of always inquiring the OTC drug use especially in geriatric population.
Topics: Aged; Anesthetics, Local; Female; Humans; Methemoglobin; Methemoglobinemia; Phenazopyridine; Renal Insufficiency
PubMed: 22987905
DOI: 10.1136/bcr-2012-006756 -
Blood Nov 2003
Topics: Anemia, Hemolytic; Blood Cells; Erythrocytes, Abnormal; Female; Gentian Violet; Hemolysis; Histocytochemistry; Humans; Oxidants; Phenazopyridine; Staining and Labeling
PubMed: 14603918
DOI: No ID Found -
Urologiia (Moscow, Russia : 1999) Jun 2020to evaluate the efficiency and safety of phenazopyridine for the treatment of patients with uncomplicated lower urinary tract infection, accompanied by pain. (Randomized Controlled Trial)
Randomized Controlled Trial
[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.
Topics: Adult; Anti-Bacterial Agents; Cystitis; Double-Blind Method; Female; Humans; Phenazopyridine; Treatment Outcome; Urinary Tract Infections
PubMed: 32597580
DOI: No ID Found -
International Urogynecology Journal Jun 2021
Topics: Anesthetics, Local; Humans; Phenazopyridine; Preoperative Care; Urinary Retention
PubMed: 33595673
DOI: 10.1007/s00192-021-04722-0 -
Drug Intelligence & Clinical Pharmacy Nov 1987
Topics: Adult; Aminopyridines; Anemia, Hemolytic; Female; Glomerulonephritis, IGA; Glucosephosphate Dehydrogenase Deficiency; Humans; Phenazopyridine
PubMed: 3678069
DOI: 10.1177/106002808702101116 -
American Journal of Perinatology Sep 1991This is a prospective study to determine whether a maternal orally administered azo dye, phenazopyridine hydrochloride, would cross into amniotic fluid, and thus be of...
This is a prospective study to determine whether a maternal orally administered azo dye, phenazopyridine hydrochloride, would cross into amniotic fluid, and thus be of potential aid in the diagnosis of rupture of the membranes. Based on anecdotal experience, we hypothesized that this compound would cross the placenta and be excreted in the fetal urine, causing discoloration of the amniotic fluid. Ten patients with uncomplicated pregnancies undergoing elective amniocentesis for obstetric indications received an oral dose of 400 mg of phenazopyridine hydrochloride 4 hours prior to the procedure. Amniotic fluid was also available from five control patients who did not receive phenazopyridine hydrochloride. The typical orange-to-red discoloration of the urine was seen in all study patients, indicating ingestion of the dye. None of the ten patients had evidence of the azo dye in their amniotic fluid by visual inspection or by spectrophotometric absorbance. After the amniotic fluid samples were acidified, the presence of the azo dye was visually demonstrable, and spectrophotometry confirmed measurable concentrations (mean +/- SE: 13.08 +/- 0.72 micrograms/ml). We conclude that although phenazopyridine hydrochloride does cross the placenta into the fetal compartment, its presence causes a visual and spectrophotometric change in the color of amniotic fluid only when the normal basic pH of amniotic fluid is acidified.
Topics: Amniotic Fluid; Coloring Agents; Evaluation Studies as Topic; Female; Fetal Membranes, Premature Rupture; Humans; Hydrogen-Ion Concentration; Maternal-Fetal Exchange; Phenazopyridine; Pregnancy; Prospective Studies; Spectrophotometry
PubMed: 1760061
DOI: 10.1055/s-2007-999402