A1,
A2,
B,
C1,
C2,
D,
E,
F,
G-H,
I-K,
L,
M,
N,
O,
P1,
P2,
Q-R,
S,
T,
U-V,
W-Z
Lasix Warnings, Precautions, Pregnancy, Nursing, Abuse - Furosemide
Lasix Warnings, Precautions, Pregnancy, Nursing, Abuse - Furosemide
WARNINGS
Tablets, Injection, and Oral Solution
In patients with hepatic
cirrhosis and ascites,
furosemide therapy
is best initiated in the hospital. In
hepatic coma
and in states of electrolyte depletion, therapy should not be instituted
until the basic condition
is improved. Sudden alterations of fluid
and electrolyte
balance in patients
with cirrhosis may
precipitate hepatic
coma; therefore, strict observation is necessary during the period
of diuresis. Supplemental potassium
chloride and, if required, an aldosterone
antagonist are helpful
in preventing hypokalemia and metabolic alkalosis.
If increasing azotemia
and oliguria occur
during treatment of
severe progressive renal
disease, furosemide
should be discontinued.
Cases of tinnitus
and reversible or
irreversible hearing
impairment have been reported. Usually, reports indicate that furosemide
ototoxicity is associated with rapid injection, severe renal
impairment, doses exceeding several times the usual recommended
dose, or concomitant
therapy with aminoglycoside antibiotics, ethacrynic acid, or other
ototoxic drugs. If
the physician elects to use high dose
parenteral therapy,
controlled intravenous
infusion is advisable (for adults, an infusion
rate not exceeding 4 mg
furosemide per minute has been used).
Injection
Pediatric Use: In
premature neonates
with respiratory distress syndrome, diuretic
treatment with furosemide
in the first few weeks of life
may increase the risk of
persistent patent ductus
arteriosus (PDA), possibly through a prostaglandin-E-mediated process.
Hearing loss in neonates
has been associated with the use of furosemide injection.
PRECAUTIONS
Tablets, Injection, and Oral Solution
General: Excessive diuresis
may cause dehydration
and blood volume reduction
with circulatory collapse
and possibly vascular thrombosis and embolism, particularly in elderly
patients. As with any effective
diuretic, electrolyte
depletion may occur
during furosemide
therapy, especially in patients receiving higher doses and a restricted
salt intake. Hypokalemia
may develop with furosemide, especially with brisk diuresis, inadequate
oral electrolyte
intake, when cirrhosis
is present, or during concomitant use of corticosteroids or ACTH.
Digitalis therapy may exaggerate metabolic effects of hypokalemia,
especially myocardial
effects.
All patients receiving furosemide
therapy should be observed for these signs or symptoms of fluid
or electrolyte imbalance
(hyponatremia, hypochloremic alkalosis, hypokalemia, hypomagnesemia
or hypocalcemia): dryness of mouth, thirst, weakness, lethargy,
drowsiness, restlessness, muscle
pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia,
arrhythmia, or gastrointestinal disturbances such as nausea
and vomiting. Increases in blood
glucose and alterations
in glucose tolerance
tests (with abnormalities of the fasting and 2-hour postprandial
sugar) have been observed, and rarely, precipitation of diabetes
mellitus has been reported.
Asymptomatic hyperuricemia
can occur and gout may
rarely be precipitated.
Oral Solution
The sorbitol present
in the vehicle may cause
diarrhea (especially
in children) when higher doses of furosemide
oral solution
are given.
Tablets, Injection, and Oral Solution
Patients allergic
to sulfonamides may also be allergic
to furosemide. The possibility exists of exacerbation
or activation of
systemic lupus erythematosus.
As with many other drugs, patients should be observed regularly
for the possible occurrence of blood
dyscrasias, liver or kidney
damage, or other idiosyncratic reactions.
Information for the Patient: Patients receiving furosemide
should be advised that they may experience
symptoms from excessive fluid and/or electrolyte
losses. The postural
hypotension that
sometimes occurs can usually be managed by getting up slowly. Potassium
supplements and/or dietary measures may be needed to control
or avoid hypokalemia.
Patients with diabetes
mellitus should be told that furosemide
may increase blood glucose
levels and thereby affect
urine glucose
tests. The skin of some
patients may be more sensitive
to the effects of sunlight while taking furosemide.
Hypertensive patients should avoid medications that may increase
blood pressure, including over-the-counter products for appetite
suppression and cold symptoms.
Laboratory Tests: Serum electrolytes (particularly
potassium), CO2, creatinine
and BUN should be determined
frequently during the first few months of furosemide
therapy and periodically thereafter. Serum and urine
electrolyte determinations
are particularly important when the patient
is vomiting profusely
or receiving parenteral
fluids. Abnormalities should be corrected or the drug
temporarily withdrawn. Other medications may also influence serum
electrolytes.
Reversible elevations of BUN
may occur and are associated with dehydration, which should be avoided,
particularly in patients with renal
insufficiency.
Urine and blood glucose
should be checked periodically in diabetics receiving furosemide,
even in those suspected of latent
diabetes.
Furosemide may lower serum
levels of calcium (rarely
cases of tetany have been reported) and magnesium. Accordingly,
serum levels of these
electrolytes should be determined periodically.
Carcinogenesis, Mutagenesis, and Impairment of Fertility:
Furosemide was tested for carcinogenicity by oral
administration
in one strain of mice and one strain
of rats. A small but significantly increased incidence of mammary
gland carcinomas occurred
in female mice at a dose
17.5 times the maximum
human dose
of 600 mg. There were marginal
increases in uncommon tumors in male
rats at a dose of 15 mg/kg
(slightly greater than the maximum
human dose) but not at
30 mg/kg.
Furosemide was devoid of mutagenic activity in various strains
of Salmonella typhimurium when tested in the presence or absence
of an in vitro metabolic activation
system, and questionably positive
for gene mutation in mouse
lymphoma cells in the
presence of rat liver
S9 at the highest dose tested. Furosemide did not induce sister
chromatid exchange
in human cells in vitro, but other studies on chromosomal
aberrations in human cells in vitro gave conflicting results.
In Chinese hamster cells
it induced chromosomal
damage but was questionably positive
for sister chromatid exchange. Studies on the induction
by furosemide of
chromosomal aberrations in mice were inconclusive. The urine
of rats treated with this drug did not induce gene
conversion in Saccharomyces
cerevisiae.
Furosemide produced no impairment
of fertility in male or
female rats, at 100 mg/kg/day
(the maximum effective
diuretic dose
in the rat and 8 times the
maximal human dose
of 600 mg/day).
Pregnancy Category C: Furosemide has been shown to
cause unexplained maternal
deaths and abortions in rabbits at 2, 4 and 8 times the maximal
recommended human dose.
There are no adequate and well-controlled studies in pregnant
women. Furosemide should be used during pregnancy only if the potential
benefit justifies the
potential risk
to the fetus.
The effects of furosemide
on embryonic and fetal
development and
on pregnant dams were studied in mice, rats and rabbits.
Furosemide caused unexplained maternal
deaths and abortions in the rabbit at the lowest dose
of 25 mg/kg (2 times the maximal recommended human
dose of 600 mg/day). In another
study, a dose of 50 mg/kg
(4 times the maximal recommended human
dose of 600 mg/day) also
caused maternal deaths
and abortions when administered to rabbits between Days 12 and 17
of gestation. In a third
study, none of the pregnant
rabbits survived a dose
of 100 mg/kg. Data from the above studies indicate fetal
lethality that can precede maternal deaths.
The results of the mouse
study and one of the three rabbit studies also showed an increased
incidence and severity
of hydronephrosis
(distention of the renal
pelvis and, in some cases,
of the ureters) in fetuses derived from the treated dams as compared
with the incidence
in fetuses from the control group.
Nursing Mothers: Because it appears in breast
milk, caution should be exercised when furosemide
is administered to a nursing
mother.
Injection
Pediatric Use: Renal calcifications (from barely
visible on x-ray to staghorn) have occurred in some severely premature
infants treated with intravenous
furosemide for edema
due to patent ductus
arteriosus and hyaline
membrane disease. The
concurrent use of chlorothiazide has been reported to decrease hypercalciuria
and dissolve some calculi.
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