Acute renal failure due to phenazopyridine (Pyridium) overdose: case report and review of the literature

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%).

Phenazopyridine associated acute interstitial nephritis and review of literature

Phenazopyridine is a urinary analgesic; commonly seen side-effects of this drug include, orange discoloration of urine, methemoglobinemia, yellowish skin discoloration, hepatitis and acute renal failure. Various case reports with phenazopyridine associated acute renal failure secondary to acute tubular necrosis have been reported in the literature. Acute kidney injury in these patients is caused by either direct injury to renal tubular epithelial cells or secondary to pigment induced nephropathy from hemolytic anemia. Hypoxic injury from phenazopyridine-induced methemoglobinemia has been well documented. We report a case of biopsy proven acute interstitial nephritis, associated with therapeutic doses of phenazopyridine without any evidence of methemoglobinemia or other mechanism of renal injury. Clinicians should be aware of the toxicity of this commonly used drug and should look closely for signs of renal insufficiency. Identifying and stopping the offending medication stays as the first step, but recent studies indicate that early steroid administration improves renal recovery, as well as decreasing the risk of progression to chronic kidney disease with fibrosis and consequent permanent renal damage.

Acute Renal Failure and Jaundice without Methemoglobinemia in a Patient with Phenazopyridine Overdose: Case Report and Review of the Literature

Phenazopyridine is a commonly used urinary analgesic available throughout the United States. Ingestion of large quantities can lead to methemoglobinemia, hemolytic anemia, jaundice, and acute renal failure. We report a case of a 78-year-old male with previously normal renal function who developed acute renal failure and jaundice without methemoglobinemia or hyperbilirubinemia after taking nearly 8 g of phenazopyridine over the course of 4 days. Initially presenting with oliguria, the urine output began to increase by day 2 of his admission, and the creatinine peaked 11 days after he began taking phenazopyridine, and he was discharged safely soon after. To our knowledge, this is the first such case of renal failure and jaundice without methemoglobinemia or hemolytic anemia in an adult patient with normal renal function.

Phenazopyridine-Induced Toxicity in an Elderly Patient Receiving a Prolonged Regimen of Therapeutic Doses

Objective:

To report a case of yellow skin pigmentation, acute renal failure, methemoglobinemia, and hemolytic anemia in a patient receiving a prolonged regimen of therapeutic doses of phenazopyridine.

Case Summary:

A 74-year-old female was admitted to the hospital with respiratory distress and acute renal failure, admission serum creatinine of 4.5 mg/dL (reference range 0.7–1.4 mg/dL), and blood urea nitrogen of 80 mg/dL (6–22 mg/dL). Upon admission, she had yellow skin pigmentation, methemoglobinemia with a methemoglobin level of 18.8% (0–3%), and hemolytic anemia with hemoglobin of 6.9 g/dL (12–16 g/dL), reticulocyte count of 5.1% (0.5–2%), and peripheral blood smear revealing Heinz body hemolysis. She had been taking phenazopyridine 200 mg 3 times per day for the 3 weeks prior to admission. Phenazopyridine was discontinued, and the patient was treated with intravenous methylene blue for methemoglobinemia and supportive care for acute renal failure, yellow skin discoloration, and hemolytic anemia. After 5 days in the hospital, the patient was discharged with baseline laboratory values and baseline respiratory status. An objective causality assessment revealed that acute renal failure was possibly and methemoglobinemia and hemolytic anemia were probably associated with phenazopyridine.

Discussion:

Phenazopyridine toxicity may occur with acute overdose or chronic administration of therapeutic doses. Severe toxicity with phenazopyridine is relatively uncommon, but when it does occur it may present as a serious clinical picture, with adverse drug reactions (ADRs) such as methemoglobinemia, hemolytic anemia, acute renal failure, and hepatitis. Removal of phenazopyridine and provision of supportive treatment for the ADRs usually results in reversal of the complications and return to baseline function. Severe cases of methemoglobinemia may need to be treated with intravenous methylene blue in addition to supportive care. This case presents the importance of understanding the risks with long-term use of therapeutic doses of phenazopyridine, especially in geriatric patients.

Conclusions:

The geriatric population and patients with renal insufficiency are at increased risk of phenazopyridine toxicity because of decreased renal clearance of phenazopyridine and its metabolites.

Acquired methaemoglobinaemia related to phenazopyridine ingestion

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.

Proteinuria in children infected with the human immunodeficiency virus

OBJECTIVES

To determine the prevalence of proteinuria in a large cohort of children infected with the human immunodeficiency virus (HIV) and their longitudinal progression during treatment with highly active antiretroviral therapy.

STUDY DESIGN

In a retrospective cohort study, 286 children infected with HIV were monitored with quantitative assays of proteinuria from January 1998 through January 2007, with monitoring of viral load, lymphocyte profiles, kidney function, and mortality rates. Proteinuria was quantitated by urine protein to creatinine ratio (Upr/cr).

RESULTS

Ninety-four (33%) had proteinuria at baseline. Of these, 32 (11.2%) had nephrotic range proteinuria (Upr/cr > or = 1.0). Initial screening was at 11 +/- 0.3 years of age, with an average follow-up of 5.6 +/- 0.1 years. The mortality rate was significantly greater in those with proteinuria. During the period of observation, 15 patients with nephrotic proteinuria died or had development of end-stage renal disease, and 16 showed improvement. Of those with intermediate range proteinuria (Upr/cr > or = 0.2 < 1.0), 3 progressed to nephrotic range proteinuria, and 39 (63%) showed resolution of the proteinuria (Upr/cr < 0.2). Improvement in proteinuria was correlated with decreasing viral load (r = 0.5; P < .01).

CONCLUSIONS

Control of viral load with highly active antiretroviral therapy appears to prevent the progression of HIV-associated renal disease and improve survival rates in infected children.