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Rate of Administration
Because of the Ca++ content of the levoleucovorin solution, no more than 16 mL (160 mg of levoleucovorin) should be injected intravenously per minute.
Potential for Enhanced Toxicity with 5-Fluorouracil
Fusilev enhances the toxicity of 5-fluorouracil. Deaths from severe enterocolitis, diarrhea, and dehydration have been reported in elderly patients receiving weekly d,l-leucovorin and 5-fluorouracil. When these drugs are administered concurrently in the palliative treatment of advanced colorectal cancer, the dosage of 5-FU must be lower than usually administered. Although the toxicities observed in patients treated with the combination of Fusilev and 5-FU are qualitatively similar to those observed with 5-FU alone, gastrointestinal toxicities (particularly stomatitis and diarrhea) are observed more commonly and may be of greater severity and of prolonged duration in patients treated with the combination.
In the first Mayo/NCCTG controlled trial, toxicity, primarily gastrointestinal, resulted in 7% of patients requiring hospitalization when treated with 5-FU alone or 5-FU in combination with 200 mg/m² of d,l-leucovorin and 20% when treated with 5-FU in combination with 20 mg/m² of d,l-leucovorin. In the second Mayo/NCCTG trial, hospitalizations related to treatment toxicity also appeared to occur more often in patients treated with the low dose d,l-leucovorin/5-FU combination than in patients treated with the high dose combination – 11% versus 3%. Therapy with Fusilev and 5-FU must not be initiated or continued in patients who have symptoms of gastrointestinal toxicity of any severity, until those symptoms have completely resolved. Patients with diarrhea must be monitored with particular care until the diarrhea has resolved, as rapid clinical deterioration leading to death can occur. In an additional study utilizing higher weekly doses of 5-FU and d,l-leucovorin, elderly and/or debilitated patients were found to be at greater risk for severe gastrointestinal toxicity.
Seizures and/or syncope have been reported rarely in cancer patients receiving d,l-leucovorin, usually in association with fluoropyrimidine administration, and most commonly in those with CNS metastases or other predisposing factors. However, a causal relationship has not been established.
Potential for interaction with trimethoprim-sulfamethoxazole
The concomitant use of d,l-leucovorin with trimethoprim-sulfamethoxazole for the acute treatment of Pneumocystis carinii pneumonia in patients with HIV infection was associated with increased rates of treatment failure and morbidity in a placebo-controlled study.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
No studies have been conducted to evaluate the potential of levoleucovorin for carcinogenesis, mutagenesis and impairment of fertility.
Use In Specific Populations
Pregnancy Category C
Animal reproduction studies have not been conducted with Fusilev. It is not known whether Fusilev can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Fusilev should be given to a pregnant woman only if clearly needed.
It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, and because of the potential for serious adverse reactions in nursing infants from Fusilev, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
[See Clinical Studies]
Clinical studies of Fusilev in the treatment of osteosarcoma did not include subjects aged 65 and over to determine whether they respond differently from younger subjects.
In the NCCTG clinical trial of Fusilev in combination with 5-FU in advanced colorectal cancer, adverse reactions were consistent with 5-FU related toxicity and were similar for patients age 65 and older and for patients younger than age 65.
Last reviewed on RxList: 6/6/2011
This monograph has been modified to include the generic and brand name in many instances.
Additional Fusilev Information
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