Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

5-Fluorouracil (5-FU) is an effective enhancer of radiation therapy (RT) in head and neck cancers. Due to rapid, predominantly hepatic metabolism by dihydropyrimidine dehydrogenase (DPD) and suggested clinical benefit from prolonged drug exposure, 5-FU is commonly given by continuous infusion. Eniluracil is a novel DPD-inactivator designed to prolong the half-life of 5-FU and provide sustained plasma concentrations of 5-FU with oral dosing. We conducted a Phase I study of the safety and efficacy of eniluracil given with oral 5-FU in patients receiving concurrent RT for recurrent or advanced squamous cell carcinomas of the head and neck. Thirteen patients with recurrent, metastatic, or high-risk (defined as an expected 2-year survival rate of <10%) head and neck cancer were enrolled and treated with concomitant chemoradiotherapy on an every-other-week schedule. Eniluracil at a fixed dose [20 mg twice a day (BID)] was given for 7 consecutive days (days 1-7). 5-FU and RT were given on 5 consecutive days (days 2-6). One patient was treated with once-daily RT (2.0 Gy fractions). The remaining patients received hyperfractionated RT (1.5-Gy fractions BID). The initial dose of 5-FU was 2.5 mg/m2 given BID. Dose escalation in patient cohorts was scheduled at 2.5-mg/m2 increments, with intrapatient dose escalation permitted. Lymphocyte DPD activity and serum 5-FU and uracil concentrations were monitored during two cycles. DPD activity was completely or nearly completely inactivated in all patients. Sustained, presumed therapeutic concentrations of 5-FU were observed at a dose of 5.0 mg/m2 given BID. Cumulative dose-limiting myelosuppression (both neutropenia and thrombocytopenia) was observed during the fourth and fifth cycles following administration of 5.0 mg/m2 5-FU BID. One patient died of neutropenic sepsis during cycle 4. Other late cycle toxicities included diarrhea, fatigue, and mucositis. Grade 3 mucositis was observed in 4 patients, but no grade 4 mucositis or grade 3 or 4 dermatitis was observed. A second patient death occurred during cycle 1 of treatment. No specific cause of death was identified. The study was subsequently discontinued. Cumulative myelosupression was the significant dose-limiting toxicity of oral 5-FU given with the DPD-inactivator eniluracil on an every-other-week schedule. Clinical radiation sensitization was not observed, based on the absence of dose-limiting mucositis and dermatitis. Alternative dosing schedules need to be examined to determine the most appropriate use of eniluracil and 5-FU as radiation enhancers.
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PMID:Phase I study of eniluracil, a dihydropyrimidine dehydrogenase inactivator, and oral 5-fluorouracil with radiation therapy in patients with recurrent or advanced head and neck cancer. 1003 77

A 71-year-old patient receiving combination chemotherapy (irinotecan, oxaliplatin and 5-fluorouracil (5-FU)) for metastatic pancreas cancer was admitted after her first cycle of chemotherapy with a severe and unexpectedly prolonged episode of neutropenic sepsis associated with pancytopenia and marked mucositis. Owing to the unusual picture, the patient was tested for mutations in the gene encoding the enzyme dihydropyrimidine dehydrogenase (DPD)--an enzyme involved in the metabolism of the chemotherapy drug 5-FU. The patient was found to be heterozygous for a mutation, DPD IVS14+1G>A, leading to the severe toxicity exhibited following this regimen caused by delayed metabolism of 5-FU. She was treated aggressively with supportive care and recovered from this episode. Importantly she was subsequently switched to an alternative chemotherapy regimen to treat her disease. She continues to maintain an excellent quality of life some 9 months after her initial diagnosis on third-line chemotherapy.
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PMID:A rare cause of susceptibility to neutropenic sepsis in a patient with metastatic pancreas cancer. 2470 34