Rasburicase-induced hemolytic anemia and methemoglobinemia: a systematic review of current reports

Since the FDA's approval of rasburicase use for treatment of tumor lysis syndrome (TLS), multiple cases of rasburicase-induced methemoglobinemia and hemolytic anemia have been reported among patients with G6PD deficiency. This study aims to provide a systematic review of cases reporting such adverse reactions to rasburicase. A literature review of published cases in PubMed, Embase, Cochrane, and Web of Science was conducted. Descriptive studies reporting cases of rasburicase-induced methemoglobinemia and/or hemolytic anemia in English were analyzed and summarized in this study. Forty-three cases, including a case from our institution, were included in this study. Most cases (60.5%) received rasburicase for TLS treatment. Almost all patients (93.8%) were tested for G6PD after rasburicase administration. The median time to symptom onset was 24 h. The median methemoglobin level was 10%, peaking after a median of 24 h. The median hemoglobin nadir was 6.1 g/dL, and most patients (n = 32) required blood transfusion. Out of 39 cases with reported outcomes, 35 patients (89.7%) recovered, while four patients (three females and one male) died. The median time to recovery was 4.5 days while the median time to death was 8 days. Screening for G6PD deficiency among high-risk patients is important but not practical in acutely severe settings. When prior screening for G6PD deficiency is not feasible, close monitoring for methemoglobinemia and hemolytic anemia is recommended. Exchange transfusion is increasingly reported as a potentially successful therapeutic modality. Ascorbic acid may provide limited benefits. Methylene blue should be avoided as it may exacerbate hemolysis among these patients.

Ascorbic Acid for Methemoglobinemia Treatment: A Case Report and Literature Review

Purpose: Ascorbic acid has been proposed as an alternative treatment for methemoglobinemia in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. However, its efficacy has never been compared to that of methylene blue given the inability of patients with G6PD deficiency to receive methylene blue. We present a case of methemoglobinemia treated with ascorbic acid in a patient without G6PD deficiency who had previously received methylene blue. Summary: A 66-year-old male was treated for methemoglobinemia deemed to be secondary to benzocaine throat spray. He received intravenous (IV) methylene blue but had a severe reaction: diaphoresis, lightheadedness, and hypotension. The infusion was stopped prior to completion. Approximately 6 days later he presented with methemoglobinemia following an additional overconsumption of benzocaine and was treated with ascorbic acid. In both instances his methemoglobin levels were >30% on arterial blood gas on admission and decreased to 6.5% and 7.8%, respectively, after administration of methylene blue and ascorbic acid. Conclusion: Ascorbic acid had a similar effect on decreasing the concentration of methemoglobin compared to methylene blue. Further research into use of ascorbic acid as a recommended agent for treatment of methemoglobinemia is warranted.

Dapsone-induced Methemoglobinemia Case Report

Methemoglobinemia is a rare disorder associated with an elevated methemoglobin level that occurs when hemoglobin is in the oxidized ferric ion form rather than reduced ferrous form. In patients with methemoglobinemia, the hemoglobin with oxidized ferric form cannot release oxygen to the tissues which leads to hypoxemia. Methemoglobinemia can be acquired or inherited. The acquired methemoglobinemia happens in patients after they take certain oxidizing drugs. This disorder is mostly treated with 2 mg/kg methylene. This disorder is mostly treated with 2 mg/kg methylene blue. However, administrating ascorbic acid as an antioxidant may also helpful, especially if a patient has taken two doses of methylene blue or if the use of methylene blue is contraindicated. Methemoglobinemia may not cure or may rebound after response to treatment, especially with long half-life drugs such as dapsone. As it states in the leaflet for methylene blue, if methemoglobinemia does not resolve after two doses, one should initiate another alternative. Ascorbic acid is a good alternative because it is an antioxidant to keep tissue from harm of free radicals and also has a role in reducing methemoglobin via co-factor nicotinamide adenine dinucleotide phosphate reeducates needed for glutathione metabolism. We discuss a case of methemoglobinemia treated successfully with oral ascorbic acid after using two doses of methylene blue. Oral ascorbic acid could be beneficial, especially when the patient was taken two doses of methylene blue.

Phenazopyridine-Induced Methemoglobinemia in a Jehovah's Witness Treated with High-Dose Ascorbic Acid Due to Methylene Blue Contradictions: A Case Report and Review of the Literature

Methemoglobinemia is an acute medical emergency that requires prompt correction. Physicians should have a high degree of suspicion of methemoglobinemia in cases that present with hypoxemia that does not resolve with supplemental oxygenation, and they should confirm this suspicion with a positive methemoglobin concentration on arterial blood gas. There are multiple medications that can induce methemoglobinemia, such as local anesthetics, antimalarials, and dapsone. Phenazopyridine is an azo dye used over-the-counter as a urinary analgesic for women with urinary tract infections, and it has also been implicated in causing methemoglobinemia. The preferred treatment of methemoglobinemia is methylene blue, but its use is contraindicated for patients with glucose-6-phosphatase deficiency or those who take serotonergic drugs. Alternative treatments include high-dose ascorbic acid, exchange transfusion therapy, and hyperbaric oxygenation. The authors report a case of a 39-year-old female who took phenazopyridine for 2 weeks to treat dysuria from a urinary tract infection and subsequently developed methemoglobinemia. The patient had contraindications for the use of methylene blue and was therefore treated with high-dose ascorbic acid. The authors hope that this interesting case promotes further research into the utilization of high-dose ascorbic acid for managing methemoglobinemia in patients who are unable to receive methylene blue.

Impact of preemptive rapid testing for glucose-6-phosphate dehydrogenase deficiency prior to rasburicase administration at a tertiary care center: a retrospective study

AIM

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common enzymopathy in humans, can cause acute hemolysis resulting from exposure to certain medications, chemicals, infections and fava beans. Rasburicase, used to manage elevated uric acid levels in the oncologic emergency of tumor lysis syndrome, is one such drug. The Food & Drug Administration (FDA) recommends testing of G6PD status prior to rasburicase administration for patients at higher risk for G6PD deficiency.

METHODS

We performed a retrospective chart review of all oncology patients for whom a semi-quantitative biochemical test for detecting G6PD deficiency was performed prior to rasburicase administration over a 2.5 year period, in a large academic metropolitan hospital.

RESULTS

We identified 16 out of 260 tested individuals as G6PD-deficient (6.1%), including six females. On average, test results were electronically available to health-care providers within 4 hours of sample collection, with most results available within 2-3 hours. Four G6PD-deficient patients developed elevated uric acid levels. Two of the G6PD-deficient patients were treated with rasburicase, and subsequently developed hemolysis, which was appropriately managed.

CONCLUSION

In summary, by providing information about G6PD status with a rapid turnaround time, we have taken a significant step towards personalized medicine in our institution. In spite of the test implementation, two out of four G6PD deficient patients, who were no longer candidates for rasburicase use, still received the drug, highlighting the need for improved provider education.

Treatment strategies for glucose-6-phosphate dehydrogenase deficiency: past and future perspectives

Glucose-6-phosphate dehydrogenase (G6PD) maintains redox balance in a variety of cell types and is essential for erythrocyte resistance to oxidative stress. G6PD deficiency, caused by mutations in the G6PD gene, is present in ~400 million people worldwide, and can cause acute hemolytic anemia. Currently, there are no therapeutics for G6PD deficiency. We discuss the role of G6PD in hemolytic and nonhemolytic disorders, treatment strategies attempted over the years, and potential reasons for their failure. We also discuss potential pharmacological pathways, including glutathione (GSH) metabolism, compensatory NADPH production routes, transcriptional upregulation of the G6PD gene, highlighting potential drug targets. The needs and opportunities described here may motivate the development of a therapeutic for hematological and other chronic diseases associated with G6PD deficiency.

Rasburicase-induced Methemoglobinemia: A Case Report and Literature Review

Rasburicase is a recombinant urate oxidase enzyme indicated for tumor lysis syndrome, a potential life-threatening oncologic emergency that occurs most commonly during initial chemotherapy for hematological malignancies. As a result of the defects in the physiological antioxidant pathway, erythrocytes of patients with glucose-6-phosphate dehydrogenase deficiency are not protected against the oxidizing stress exerted by hydrogen peroxide generated with the administration of rasburicase. The authors report a 14-year-old patient, diagnosed with T-cell acute lymphoblastic leukemia, who developed methemoglobinemia and hemolytic anemia with low oxygen saturation after starting steroids, hyperhydratation, and rasburicase administration. The complications resolved with supportive therapy only.

Efficacy and Safety of Parenteral High-Dose Vitamin C Therapy in Pediatric Patients: A Scoping Review

OBJECTIVES

Recently, several adult trials have investigated the potential benefit of high-dose vitamin C therapy in critically ill patients. In pediatric patients, little is known on the efficacy, safety, and risk of high-dose vitamin C therapy. We aimed to review the efficacy and potential harm associated with high-dose vitamin C treatment.

DATA SOURCES

We searched MEDLINE, EMBASE, Cochrane Library, and National Institute of Health Clinical Trials Register.

STUDY SELECTION

We included studies in neonatal and pediatric patients who received IV or intra-arterial high-dose vitamin C (ascorbic acid) defined as greater than or equal to 75 mg/kg/d.

DATA EXTRACTION

Two independent investigators screened articles and extracted data.

DATA SYNTHESIS

We found 1,364 articles, assessed 193 full texts for eligibility, and identified 12 eligible studies. These studies included 855 patients, with 194 receiving high-dose vitamin C. The age of patients who received high-dose vitamin C ranged from 2 hours after delivery to 8.4 years (median 2.4 yr), and the vitamin C dose ranged from 100 to 1,500 mg/kg/d (median 260.5 mg/kg/d). Four studies were double-blind randomized controlled trials, and no clinical efficacy outcome was reported in favor of or against vitamin C. Furthermore, no adverse event or signal of harm was reported with high-dose vitamin C.

CONCLUSIONS

In 12 studies with 194 children treated with parenteral high-dose vitamin C, there was no evidence of clinical efficacy or inferior clinical outcomes in double-blind randomized controlled trials, and no reported harmful effects. These findings justify further investigations of this treatment in children.

Naphthalene Toxicity in a Three-Year-Old Child Complicated by Severe Hemolytic Anemia and Mild Methemoglobinemia: A Case Report

BACKGROUND

Exposure to naphthalene, which is widely used in mothballs, does not usually produce adverse effects. However, naphthalene can be toxic, especially in individuals with underlying conditions such as glucose-6-phosphate-dehydrogenase (G6PD) deficiency.

CASE REPORT

A 3-year-old boy was brought to our Emergency Department after accidentally ingesting naphthalene mothballs 3 days prior to presentation. Laboratory investigations revealed that he had severe hemolytic anemia and mild methemoglobinemia (6%), which were treated with ascorbic acid and N-acetylcysteine. The patient tested positive for G6PD deficiency after stabilization and completion of his treatment. All provided treatments were administered empirically; test results were available only after the patient was discharged. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Naphthalene exposure is a common pediatric presentation with various complications that can occur in certain high-risk individuals, such as those with G6PD deficiency. Emergency physicians should be aware of this to anticipate and be able to treat worsening toxicity.

Harm of IV High-Dose Vitamin C Therapy in Adult Patients: A Scoping Review

OBJECTIVES

The potential harm associated with the use of IV vitamin C has not been systematically assessed. We aimed to review the available evidence on harm related to such treatment.

DATA SOURCES

We searched MEDLINE, EMBASE, Cochrane Library, National Institute of Health Clinical Trials Register, and World Health Organization International Clinical Trials Registry Platform.

STUDY SELECTION

We included studies in adult population that reported harm related to IV high-dose vitamin C which we defined as greater than or equal to 6 g/d, greater than or equal to 75 mg/kg/d, or greater than or equal to 3 g/m/d.

DATA EXTRACTION

Two independent investigators screened records and extracted data.

DATA SYNTHESIS

We identified 8,149 reports, of which 650 full text were assessed for eligibility, leaving 74 eligible studies. In these studies, 2,801 participants received high-dose vitamin C at a median (interquartile range) dose of 22.5 g/d (8.25-63.75 g/d), 455 mg/kg/d (260-925 mg/kg/d), or 70 g/m/d (50-90 g/m/d); and 932 or more adverse events were reported. Among nine double-blind randomized controlled trials (2,310 patients), adverse events were reported in three studies with an event rate per patient for high-dose vitamin C identical to placebo group in one study (0.1 [1/10] vs 0.1 [1/10]), numerically lower in one study (0.80 [672/839] vs 0.82 [709/869]), and numerically higher in one study (0.33 [24/73] vs 0.23 [17/74]). Six double-blind randomized controlled trials reported no adverse event in either group. Five cases of oxalate nephropathy, five cases of hypernatremia, three cases of hemolysis in glucose-6-phosphate dehydrogenase deficiency patients, two cases of glucometer error, and one case of kidney stones were also reported overall.

CONCLUSIONS

There is no consistent evidence that IV high-dose vitamin C therapy is more harmful than placebo in double-blind randomized controlled trials. However, reports of oxalate nephropathy, hypernatremia, glucometer error, and hemolysis in glucose-6-phosphate dehydrogenase deficiency patients warrant specific monitoring.

Local Anesthetic-Induced Methemoglobinemia During Pregnancy: A Case Report and Evaluation of Treatment Options

BACKGROUND

Methemoglobinemia is a well-recognized adverse drug reaction related to the use of certain local anesthetic agents. The mainstay of treatment for methemoglobinemia is i.v. methylene blue, along with provision of supplemental oxygen; however, methylene blue is listed as a category X teratogen. This poses an issue should methemoglobinemia develop during pregnancy.

CASE REPORT

A 35-year-old, 20-week and 5-day gravid female was transferred from an outpatient oral surgeon's office for hypoxia. She was undergoing extraction of 28 teeth and was administered an unknown, but "large" quantity of prilocaine during the procedure. Given this exposure, the concern was for methemoglobinemia. This was confirmed with co-oximetry, which showed 34.7% methemoglobin. The initial treatment plan was methylene blue; however, this drug is a category X teratogen. Thus, an interdisciplinary team deliberated and decided on treatment with high-dose ascorbic acid and transfusion of a single unit of packed red blood cells. The patient was managed with noninvasive ventilation strategies and a total of 8 g ascorbic acid. She was discharged on hospital day 3 with no obstetric issues noted. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Intravenous ascorbic acid appears to be a potential alternative to methylene blue in this patient population. The data surrounding teratogenicity of methylene blue are mostly related to intra-amniotic or intra-uterine administration. In life-threatening cases of methemoglobinemia during pregnancy, the benefits of i.v. methylene blue may outweigh the risks.

Review and drug therapy implications of glucose-6-phosphate dehydrogenase deficiency

PURPOSE

The pathophysiology, diagnosis, and medication-use implications of glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common enzyme deficiency in humans, are reviewed.

SUMMARY

Originally identified as favism in patients who experienced hemolysis after ingestion of fava beans, G6PD deficiency results from an X-linked chromosomal mutation that leads to reduced activity of the enzyme responsible for the final step of the pentose phosphate pathway, through which reduced nicotinamide adenine dinucleotide phosphate required for protection of cells from oxidative stress is produced. G6PD deficiency affects about 400 million people worldwide. Diagnosis of G6PD can be made through detection of enzymatic activity (by spectrophotometric testing, fluorescence testing, or formazan-based spot testing) or molecular analysis to detect known mutations of the gene encoding G6PD. Most individuals with G6PD deficiency are asymptomatic throughout life. Symptoms of acute hemolysis associated with G6PD deficiency include anemia, fatigue, back or abdominal pain, jaundice, and hemoglobinuria. The most common precipitators of oxidative stress and hemolysis in G6PD deficiency include medication use and infection.

CONCLUSION

G6PD deficiency should be considered in patients who experience acute hemolysis after exposure to known oxidative medications, infection, or ingestion of fava beans. A diagnosis of G6PD deficiency is most often made through enzymatic activity detection, but molecular analysis may be required in females heterozygous for the disorder. When clinically feasible, rasburicase, primaquine, dapsone, pegloticase, and methylene blue should not be used until a G6PD diagnostic test has been performed.