Fluoropyrimidine therapy: hyperbilirubinemia as a consequence of hemolysis

Adverse drug events associated with fluorouracil use in patients with metastatic colorectal cancer: a real-world pharmacovigilance study based on the FDA adverse event reporting system

BACKGROUND

Fluorouracil (5-FU) is widely used to treat metastatic colorectal cancer (mCRC), but real-world safety data is limited. Our study aimed to evaluate 5-FU's safety profile in a large mCRC population using the FAERS database.

RESEARCH DESIGN AND METHODS

We conducted disproportionality analyses to identify adverse drug events associated with 5-FU use in mCRC patients from 2004 to 2023. Subgroup analyses, gender difference analyses, and logistic regression were also performed.

RESULTS

We identified 1,458 reports with 5-FU as the primary suspected drug, with males accounting for 48.8% of reports. Gastrointestinal disorders were the most common adverse event (864 cases), while pregnancy-related conditions showed the strongest signal intensity (ROR = 2.97). We found 19 preferred terms with positive signals, including ischemic hepatitis (ROR = 59.32), blood iron increased (ROR = 59.32), and stress cardiomyopathy (ROR = 51.94). Males were more susceptible to weight loss and skin toxicity. Most adverse events occurred within the first month of 5-FU administration.

CONCLUSION

Our study provides a comprehensive analysis of 5-FU's safety profile in mCRC patients, helping healthcare professionals mitigate risks in clinical practice.

Oral Uracil and Tegafur Compared With Classic Cyclophosphamide, Methotrexate, Fluorouracil As Postoperative Chemotherapy in Patients With Node-Negative, High-Risk Breast Cancer: National Surgical Adjuvant Study for Breast Cancer 01 Trial

Purpose

The primary aim of this study was to compare the effectiveness of oral uracil-tegafur (UFT) with that of classical cyclophosphamide, methotrexate, and fluorouracil (CMF) given as postoperative adjuvant treatment to women with node-negative, high-risk breast cancer.

Patients and Methods

Women with node-negative, high-risk breast cancer were randomly assigned to receive either 2 years of UFT or six cycles of CMF after surgery. The primary end point was relapse-free survival (RFS). Overall survival (OS), toxicity, and quality of life (QOL) were secondary end points. The hypothesis was that UFT was not inferior to CMF in terms of RFS.

Results

Between October 1996 and April 2001, a total of 733 patients were randomly assigned to receive either treatment. The median follow-up time was 6.2 years. The RFS rates at 5 years were 88.0% in the CMF arm and 87.8% in the UFT arm. OS rates were 96.0% and 96.2%, respectively. The hazard ratios of the UFT arm relative to the CMF arm were 0.98 for RFS (95% CI, 0.66 to 1.45; P = .92) and 0.81 for OS (95% CI, 0.44 to 1.48; P = .49). The toxicity profiles differed between the two groups. The QOL scores were better for patients given UFT than those given CMF.

Conclusion

RFS and OS with oral UFT were similar to those with classical CMF. Given the higher QOL scores, oral UFT is a promising alternative to CMF for postoperative adjuvant chemotherapy in women with node-negative, high-risk breast cancer.

Capecitabine: an overview of the side effects and their management

Xeloda (capecitabine), a thymidine phosphorylase activated fluoropyrimidine carbamate, is currently the only universally approved orally administered 5-fluorouracil (5-FU) prodrug. It belongs to a newer generation of orally administered fluoropyrimidines. It has been developed because of the clinical need for efficient, tolerable and convenient agents, which do not require continuous infusion. Capecitabine is not a cytotoxic drug in itself, but via a three-step enzymatic cascade, it is converted to 5-FU mainly within human cancer cells. While the drug compares favorably with 5-FU in patients with advanced or metastatic colorectal cancer and pretreated breast cancer, it also has an improved toxicity profile, mainly of gastrointestinal and dermatologic effects with a significantly lower incidence of grade 3/4 myelotoxicity compared with infusional 5-FU-based chemotherapy. Capecitabine's selective activation within the tumor allows for less systemic toxicity events. A gradient of fluoropyrimidine toxicity is observed: high in the US and low in East Asia. In addition, there is a discrepancy in tolerance of dose among patients treated in the US vs. Europe. Although patients can take the drug orally in the convenience of their own home, the key to successful management of capecitabine is the clinician's awareness of its severe, but low in incidence, adverse effects, and the patients' education, emphasizing compliance with the treatment plan, prevention and timely recognition of its toxicities.