Evaluation of thiamine for the prevention of ifosfamide-induced encephalopathy

Ifosfamide-Induced Neurotoxicity in Children with Solid Tumors: A Seven Year Retrospective Analysis of Incidence and Risk Factors

Background: Patients with cancer treated with the pro-drug ifosfamide may experience drug-induced neurotoxicity. Ifosfamide-induced neurotoxicity (IIN) is well described in the adult literature, but there is limited knowledge about this toxicity in pediatrics, especially in children with solid tumors. Methods: In this retrospective descriptive study, the author reviewed 7 years of clinical data regarding patients with solid tumors who received ifosfamide at a large, urban pediatric medical center. The author used descriptive statistics and logistic regression to describe the incidence of IIN and identify demographic and clinical factors most likely to be associated with the toxicity. Results: In a sample of 169 pediatric patients who received ifosfamide between 2011 and 2018, 13% developed symptoms of IIN. The author identified ifosfamide doses >2,000 mg/m² to be a risk factor for IIN in the study sample (OR 17.82; 95 CI [2.17, 146.18]; p = .0073) and cited other variables as possible risk factors, though each could be linked to participants' ifosfamide exposure. Discussion: This study is the largest to describe IIN specifically in the pediatric solid tumor population. The study findings suggest the pattern of toxicity observed in adult patients should not be assumed in children. The author identified one risk factor that may predispose children to develop IIN and recommends further attention be paid to this toxicity in the pediatric population.

Ifosfamide-induced Encephalopathy With Rapid Response to Thiamine: A Pediatric Case

Ifosfamide is an important chemotherapeutic agent used in the therapeutic protocols of many malignant tumors. Central nervous system toxicity of ifosfamide manifests with encephalopathy in 10% to 30% of patients treated with ifosfamide. Thiamine and methylene blue have been reported beneficial in the treatment and prevention of ifosfamide-induced encephalopathy (IIE). We describe an episode of encephalopathy developed at the third cycle of ifosfamide treatment in a child with Ewing sarcoma. With the administration of thiamin, the encephalopathy resolved and no episode was noted during subsequent courses of ifosfamide. Previous use of cisplatin, concomitant use of opioids, low levels of serum albumin and hemoglobin, and elevated levels of serum creatinine are potential risk factors for IIE. The current case illustrates the possibility of IIE even in the absence of such additional risk factors, treated successfully with thiamin and draws attention to the need for close neurological monitorization of patients treated with ifosfamide.

Neurologic Complications in Patients with Cancer

Neurologic symptoms are commonly seen in patients with cancer and can be among the most challenging to diagnose and manage. It is often difficult to determine if new neurologic symptoms are secondary to direct effects of a malignant lesion, systemic complications of disease, paraneoplastic disorders, or side effects of cancer treatment itself. However, early diagnosis and treatment of each of these conditions can improve patients' quality of life and long-term functional outcomes. In this review, we describe a systematic approach to the diagnosis of new neurologic symptoms in patients with known malignancy. We have categorized the neurologic complications of cancer through a mechanistic approach, with an emphasis on ascertaining underlying pathophysiology to guide treatment choice. This review focuses on the acute neurologic complications of cancer that require hospital admission.

Ifosfamide-related encephalopathy with severe clinical presentations in children with cancer

INTRODUCTION

Ifosfamide is an alkylating agent, mostly used against variety of solid tumors in pediatric oncology practice. Although hemorrhagic cystitis is known as a common adverse effect, encephalopathy is the another one that should be kept in mind. It may occur in 2-5% of the children, and manifested by different clinical spectrums such as somnolence, lethargy, irritability, excitement, disorientation, confusion, weakness, hallucinations, seizures, movement disorders, and coma.

CASE REPORT

Herein, we present two patients who developed generalized seizure activity and one who developed coma during ifosfamide infusion.Management and outcome: In the first two patients, ifosfamide infusion was discontinued and intravenous diazepam was given. Their seizure stopped in a few minutes and neurological examination was back to normal, and no focal deficits were observed. In the third patient, ifosfamide infusion was discontinued, methylene blue and thiamine were given. After the tenth dose of methylene blue, she became neurologically normal, without any mental and motor deficit. Nevertheless, later she developed febrile neutropenia, septic shock and she died.

DISCUSSION

These cases highlight that pediatric oncologists and hematologists should be aware of possibility of severe neurological toxicity after administration of ifosfamide in adolescent patients. Apart from seizure, clinicians should also be prepared to notice drowsiness during ifosfamide infusions in children. Most of the time cessation of ifosfamide and hydration is enough. However, in severe toxicities there is a risk of irreversible neurological damage, and for these patients methylene blue (MB) and thiamine treatment should be kept in mind.

Adverse event profiles of ifosfamide-induced encephalopathy analyzed using the Food and Drug Administration Adverse Event Reporting System and the Japanese Adverse Drug Event Report databases

PURPOSE

Ifosfamide is extensively used to treat several malignant conditions. Administration of ifosfamide can cause encephalopathy and other neurotoxic effects. The aim of this study was to obtain novel information on the onset profiles of ifosfamide-induced encephalopathy (IIE) considering other associated clinical factors using the US Food and Drug Administration Adverse Event Reporting System (FAERS) and the Japanese Adverse Drug Event Report (JADER) databases.

METHODS

We analyzed the reports of encephalopathy between 2004 and 2018 from the FAERS and JADER databases. To define IIE, we used the Medical Dictionary for Regulatory Activities (MedDRA) preferred terms and standardized queries. The reporting odds ratios (ROR) at 95% confidence interval (CI) was used to detect the signal for IIE and adjusted for covariates using a multivariate logistic regression technique. We evaluated the time-to-onset profile of IIE and used the association rule mining technique to discover undetected associations, such as potential risk factors.

RESULTS

In the FAERS database, the ROR (CI) for encephalopathy (preferred term, PT) and encephalopathy (standardized MedDRA queries, SMQ) was 56.58 (51.69-61.93) and 1.57 (1.48-1.67), respectively. In the JADER database, the ROR (95% CI) for encephalopathy (PT) and encephalopathy (SMQ) was 13.54 (9.91-18.50) and 1.24 (1.01-1.53), respectively. The multivariate logistic regression analysis showed a significant contribution in IIE signal in the ≥ 60 year group (p = 0.00094; vs. < 60 year group) and ≥ 2000 mg/m² dosage group (p = 0.00045; vs. < 2000 mg/m² dosage group). The association rules of {ifosfamide, aprepitant} → {encephalopathy (SMQ)} demonstrated high lift values. The average dose of ifosfamide in patients with encephalopathy (PT) and without encephalopathy (PT) was 2022.8 ± 592.8 (mean ± standard deviation) and 1568.5 ± 703.2 mg/m², respectively (p < 0.05). Encephalopathy within the first 7 days of ifosfamide administration was 94.1% for encephalopathy (PT) and 87.7% for encephalopathy (SMQ), respectively.

CONCLUSIONS

The present analysis demonstrated that the incidence of encephalopathy with ifosfamide should be closely monitored for a short onset (within 7 days). The patients who are administered a high dose of ifosfamide or co-administrated aprepitant should be carefully monitored for the development of encephalopathy.