WARNINGS
Included as part of the PRECAUTIONS section.
PRECAUTIONS
Increased Risk Of Serious Or Fatal Adverse Reactions In Patients
With Low Or Absent Dipyrimidine Dehydrogenase (DPD) Activity
Based on postmarketing reports, patients with certain
homozygous or certain compound heterozygous mutations in the DPD gene that
result in complete or near complete absence of DPD activity are at increased
risk for acute early-onset of toxicity and severe, life-threatening, or fatal
adverse reactions caused by fluorouracil (e.g., mucositis, diarrhea,
neutropenia, and neurotoxicity). Patients with partial DPD activity may also
have increased risk of severe, life-threatening, or fatal adverse reactions
caused by fluorouracil.
Withhold or permanently discontinue fluorouracil based on
clinical assessment of the onset, duration and severity of the observed
toxicities in patients with evidence of acute early-onset or unusually severe
toxicity, which may indicate near complete or total absence of DPD activity. No
fluorouracil dose has been proven safe for patients with complete absence of
DPD activity. There is insufficient data to recommend a specific dose in
patients with partial DPD activity as measured by any specific test.
Cardiotoxicity
Fluorouracil can cause cardiotoxicity, including angina,
myocardial infarction/ischemia, arrhythmia, and heart failure, based on
postmarketing reports. Reported risk factors for cardiotoxicity are administration
by continuous infusion rather than intravenous bolus and presence of coronary
artery disease. Withhold fluorouracil for cardiotoxicity. The risks of
resumption of fluorouracil in patients with cardiotoxicity that has resolved
have not been established.
Hyperammonemic Encephalopathy
Fluorouracil can cause hyperammonemic encephalopathy in
the absence of liver disease or other identifiable cause, based on
postmarketing reports. Signs or symptoms of hyperammonemic encephalopathy began
within 72 hours after initiation of fluorouracil infusion; these included
altered mental status, confusion, disorientation, coma, or ataxia, in the
presence of concomitant elevated serum ammonia level. Withhold fluorouracil for
hyperammonemic encephalopathy and initiate ammonialowering therapy. The risks
of resumption of fluorouracil in patients with hyperammonemic encephalopathy
that has resolved have not been established.
Neurologic Toxicity
Fluorouracil can cause neurologic toxicity, including
acute cerebellar syndrome and other neurologic events, based on postmarketing
reports. Neurologic symptoms included confusion, disorientation, ataxia, or
visual disturbances. Withhold fluorouracil for neurologic toxicity. There are
insufficient data on the risks of resumption of fluorouracil in patients with
neurologic toxicity that has resolved.
Diarrhea
Fluorouracil can cause severe diarrhea. Withhold
fluorouracil for Grade 3 or 4 diarrhea until resolved or decreased in intensity
to Grade 1, then resume fluorouracil at a reduced dose. Administer fluids, electrolyte
replacement, or antidiarrheal treatments as necessary.
Palmar-Plantar Erythrodysesthesia (Hand-Foot Syndrome)
Fluorouracil can cause palmar-plantar erythrodysesthesia,
also known as hand-foot syndrome (HFS). Symptoms of HFS include a tingling
sensation, pain, swelling, and erythema with tenderness, and desquamation. HFS
occurs more commonly when fluorouracil is administered as a continuous infusion
than when fluorouracil is administered as a bolus injection, and has been
reported to occur more frequently in patients with previous exposure to
chemotherapy. HFS is generally observed after 8 to 9 weeks of fluorouracil
administration but may occur earlier. Institute supportive measures for symptomatic
relief of HFS. Withhold fluorouracil administration for Grade 2 or 3 HFS;
resume fluorouracil at a reduced dose when HFS is completely resolved or
decreased in severity to Grade 1.
Myelosuppression
Fluorouracil can cause severe and fatal myelosuppression
which may include neutropenia, thrombocytopenia, and anemia. The nadir in
neutrophil counts commonly occurs between 9 and 14 days after fluorouracil
administration. Obtain complete blood counts prior to each treatment cycle,
weekly if administered on a weekly or similar schedule, and as needed. Withhold
fluorouracil until Grade 4 myelosuppression resolves; resume fluorouracil at a
reduced dose when myelosuppression has resolved or improved to Grade 1 in
severity.
Mucositis
Mucositis, stomatitis or esophagopharyngitis, which may
lead to mucosal sloughing or ulceration, can occur with fluorouracil. The
incidence is reported to be higher with administration of fluorouracil by intravenous
bolus compared with administration by continuous infusion. Withhold fluorouracil
administration for Grade 3 or 4 mucositis; resume fluorouracil at a reduced
dose once mucositis has resolved or decreased in severity to Grade 1.
Increased Risk Of Elevated International Normalized Ratio
(INR) With Warfarin
Clinically significant elevations in coagulation
parameters have been reported during concomitant use of warfarin and
fluorouracil. Closely monitor patients receiving concomitant
coumarin-derivative anticoagulants such as warfarin for INR or prothrombin time
in order to adjust the anticoagulant dose accordingly [see DRUG INTERACTIONS].
Embryofetal Toxicity
Based on its mechanism of action, fluorouracil can cause
fetal harm when administered to a pregnant woman. In animal studies,
administration of fluorouracil at doses lower than a human dose of 12 mg/kg caused
teratogenicity. If this drug is used during pregnancy, or if the patient
becomes pregnant while taking this drug, the patient should be apprised of the
potential hazard to a fetus. Advise females of reproductive potential and males
with female partners of reproductive potential to use effective contraception
during and for 3 months following cessation of therapy with fluorouracil [see
Use In Specific Populations, CLINICAL PHARMACOLOGY, and Nonclinical
Toxicology].
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Carcinogenicity studies have not been performed with
fluorouracil. Fluorouracil was mutagenic in vitro in the bacterial reverse
mutation (Ames) assay and induced chromosomal aberrations in hamster fibroblasts
in vitro and in mouse bone marrow in the in vivo mouse micronucleus assay.
Administration of fluorouracil intraperitoneally to male
rats at dose levels equal to or greater than 1.7- fold the human dose of 12
mg/kg induced chromosomal aberrations in spermatogonia and inhibition of spermatogonia
differentiation resulting in transient infertility. In female rats,
intraperitoneal administration of fluorouracil during the pre-ovulatory phases
of oogenesis at dose levels equal to or greater than 0.33 times a human dose of
12 mg/kg resulted in decreased incidence of fertile matings, increased
pre-implantation loss, and fetotoxicity.
Use In Specific Populations
Pregnancy
Teratogenic Effects
Pregnancy Category D
Risk Summary
There are no adequate and well-controlled studies with
fluorouracil in pregnant women. Based on its mechanism of action, fluorouracil
can cause fetal harm when administered to a pregnant woman. Administration of
fluorouracil to rats and mice during selected periods of organogenesis, at
doses lower than a human dose of 12 mg/kg, caused embryolethality and
teratogenicity. Malformations included cleft palate and skeletal defects. In
monkeys, maternal doses of fluorouracil higher than an approximate human dose
of 12 mg/kg resulted in abortion. If this drug is used during pregnancy, or if the
patient becomes pregnant while taking this drug, apprise the patient of the
potential hazard to a fetus [see CLINICAL PHARMACOLOGY].
Animal Data
Malformations including cleft palate, skeletal defects
and deformed appendages (paws and tails) were observed when fluorouracil was
administered by intraperitoneal injection to mice at doses at or above 10 mg/kg
(approximately 0.06 times a human dose of 12 mg/kg on a mg/m² basis) for 4 days
during the period of organogenesis. Similar results were observed in hamsters
administered fluorouracil intramuscularly at doses lower than those
administered in commonly used clinical treatment regimens. In rats,
administration of fluorouracil by intraperitoneal injection at doses greater
than 15 mg/kg (approximately 0.2 times a human dose of 12 mg/kg on a mg/m²
basis) for a single day during organogenesis resulted in delays in growth and
malformations including micro-anophthalmos. In monkeys, administration of
fluorouracil during organogenesis at doses approximately equal to a human dose
of 12 mg/kg on a mg/m² basis resulted in abortion; at a 50% lower dose,
resorptions and decreased fetal body weights were reported.
Nursing Mothers
It is not known whether fluorouracil or its metabolites
are present in human milk. Because many drugs are present in human milk and
because of the potential for serious adverse reactions in nursing infants from
fluorouracil, a decision should be made whether to discontinue nursing or to
discontinue the drug, taking into account the importance of the drug to the
mother.
Pediatric Use
The safety and effectiveness in pediatric patients have
not been established.
Geriatric Use
Reported clinical experience has not identified
differences in safety or effectiveness between the elderly and younger
patients.
Females And Males Of Reproductive Potential
Contraception
Females
Based on its mechanism of action, fluorouracil can cause
fetal harm when administered to a pregnant woman. Advise females of
reproductive potential to use effective contraception during treatment with fluorouracil
and for up to 3 months following cessation of therapy [see Use In Specific
Populations].
Males
Fluorouracil may damage spermatozoa. Advise males with
female partners of reproductive potential to use effective contraception during
and for 3 months following cessation of therapy with fluorouracil [see Nonclinical
Toxicology].
Infertility
Females
Advise females of reproductive potential that, based on
animal data, fertility may be impaired while receiving fluorouracil [see
Nonclinical Toxicology].
Males
Advise males of reproductive potential that, based on
animal data, fertility may be impaired while receiving fluorouracil [see Nonclinical
Toxicology].