Gastrografin
Generic Name: diatrizoate meglumine and diatrizoate sodium
Dosage Form: Solution
Gastrografin Description
Gastrografin (Diatrizoate Meglumine and
Diatrizoate Sodium Solution) is a palatable
lemon-flavored water-soluble iodinated radiopaque contrast medium for oral or rectal
administration only. Each mL contains
660 mg diatrizoate meglumine and 100 mg
diatrizoate sodium; pH has been adjusted to
6.0 to 7.6 with sodium hydroxide. Each mL
contains approximately 4.8 mg (0.21 mEq)
sodium and 367 mg organically bound
iodine. Inactive ingredients: edetate
disodium, flavor, polysorbate 80, purified
water, saccharin sodium, simethicone, and
sodium citrate.
Diatrizoate meglumine is designated chemically
as 1-deoxy-1-(methylamino)-D-glucitol
3,5-diacetamido-2,4,6-triiodo-benzoate
(salt); diatrizoate sodium is monosodium 3,
5-diacetamido-2,4,6-triiodobenzoate.
Structural formulas:
Gastrografin - Clinical Pharmacology
The most important characteristic of contrast
media is the iodine content. The relatively
high atomic weight of iodine contributes sufficient
radiodensity for radiographic contrast
with surrounding tissues.
Diagnostic enteral radiopaque agents
have few known pharmacological effects.
Diatrizoate meglumine and diatrizoate
sodium exert a mild laxative effect attributable
to their high osmolarity.
Diatrizoate meglumine and diatrizoate
sodium are sparingly absorbed from the
intact gastrointestinal tract, and therefore
permit gastrointestinal opacification and
delineation after oral or rectal administration.
Oral administration is used for
radiographic evaluation of the esophagus,
stomach and proximal small intestine.
Rectal administration is used for examination
of the colon; however, visualization of
the distal small bowel is generally unsatisfactory, since the hypertonicity of the
medium causes intraluminal diffusion of
water with subsequent dilution of the
medium. Enough absorption from the gastrointestinal
tract to permit incidental
visualization of the urinary tract has been
reported; this should also be considered
when thyroid testing is being contemplated,
since iodine-mediated thyrotropic
effects may occur (see PRECAUTIONS).
Indications and Usage for Gastrografin
Gastrografin (Diatrizoate Meglumine and
Diatrizoate Sodium Solution) is indicated
for radiographic examination of segments
of the gastrointestinal tract (esophagus,
stomach, proximal small intestine, and
colon). The preparation is particularly indicated
when a more viscous agent such as
barium sulfate, which is not water-soluble,
is not feasible or is potentially dangerous.
Gastrografin may also be used as an
adjunct to contrast enhancement in computed
tomography of the torso (body
imaging); the preparation is indicated, in
conjunction with intravenous administration
of a radiopaque contrast agent, when
unenhanced imaging may not provide sufficient
definition in distinguishing normal
loops of bowel from adjacent organs or
areas of suspected pathology.
Contraindications
There are no absolute contraindications to
the use of Gastrografin (Diatrizoate Meglumine
and Diatrizoate Sodium Solution)
as recommended (see PRECAUTIONS,
General).
Warnings
A 1 in 4.6 (1:4.6) dilution of Gastrografin
yields an approximately isotonic 16.5 percent
diatrizoate salts solution; less dilute
solutions are hypertonic and may lead to
intraluminal movement of fluid with resulting
hypovolemia. In young or debilitated
children and in elderly cachectic persons,
the loss of plasma fluid may be sufficient
to cause a shock-like state. See DOSAGE
AND ADMINISTRATION for recommended
dilutions that must be used for infants and
young children (under 10 kg) and for dehydrated
or debilitated patients. Electrolyte
disturbances must be corrected prior to
using hypertonic solutions. In debilitated
patients and in patients with electrolyte
imbalances, postprocedural monitoring of
hydration, serum osmolarity, electrolytes
and clinical status is essential. In pediatric
or severely debilitated patients, the maintenance
of an open intravenous fluid line
for rehydration may be advisable should
hypotension or shock supervene.
The possibility of accidental aspiration into
the trachea or into a tracheoesophageal fistula
following ingestion or instillation, could
result in serious pulmonary complications
(e.g., pulmonary edema or pneumonitis)
even though the medium may be promptly
expectorated. Bronchial entry of any orally
administered contrast medium causes a
copious osmotic effusion. Therefore, pulmonary
entry by aspiration and use in
patients with esophagotracheal fistula
should be avoided.
Precautions
General
Diagnostic procedures which involve the
use of radiopaque contrast agents should
be carried out under the direction of personnel
with the prerequisite training and
with a thorough knowledge of the particular
procedure to be performed. Appropriate
facilities should be available for coping with
any complication of administration, as well
as for treatment of reaction to the contrast
medium.
The possibility of a reaction should always
be considered. Patients at increased risk
include those with a history of a previous
reaction to a contrast medium, patients with
a known sensitivity to iodine per se, and
patients with a known clinical hypersensitivity
(bronchial asthma, hay fever, and food
allergies). A positive history of allergies or
hypersensitivity does not arbitrarily contraindicate
the use of a contrast agent when a
diagnostic procedure is thought essential,
but caution should be exercised (see ADVERSE
REACTIONS, and PRECAUTIONS,
Information for the Patient).
Rectal administration of undiluted
Gastrografin (Diatrizoate Meglumine and
Diatrizoate Sodium Solution) in any patient,
particularly with large doses and/or in those
with overdistention, has been reported to
be associated with mucosal irritation.
Cases of hyperthyroidism have been
reported with the use of oral contrast
media. Some of these patients reportedly
had multinodular goiters which may have
been responsible for the increases hormone
synthesis in response to excess
iodine. Administration of an intravascular
iodinated radiopaque diagnostic agent to
a hyperthyroid patient precipitated thyroid
storm; a similar situation could follow administration
of oral preparations of iodides.
Therefore, caution should be exercised
when administering enteral gastrointestinal
radiopaque agents to hyperthyroid and
euthyroid goiterous patients.
Consideration should be given to the
potential for precipitation of water-soluble
contrast agents under conditions that may
promote hyperacidity (i.e., fasting, emotional
upset, or stress). Harmful effects
directly attributable to precipitate formation
have not been reported. However, the
possibility of interpreting the precipitate
radiologically as an anatomical abnormality
(i.e., ulceration of the stomach or small
intestine) or injury, should be kept in mind.
Information for the Patient
Patients should receive the following information
and instructions:
- This drug has been prescribed to perform
an x-ray of the gastrointestinal
tract.
- Inform the physician if pregnant or if
allergic to iodine, any foods, or x-ray
materials.
- The iodine in diatrizoate salts may
interfere with some thyroid tests if
these are needed in the future. Inform
the attending physician at that time
about this gastrointestinal study.
- This drug may cause abdominal
cramping, nausea, vomiting, diarrhea,
skin rashes, itching, heartburn,
dizziness, or headache in some
patients, but most reactions are mild
and pass quickly.
Drug/Laboratory Test Interactions
Thyroid Function Tests
The results of protein bound iodine (PBI)
and radioactive iodine uptake studies,
which depend on iodine estimations, will
not accurately reflect thyroid function for
six months, and possibly as long as one
year, following the administration of diagnostic
enteral radiopaque media.
Thyroid function tests, if indicated, generally
should be performed prior to the
administration of any iodinated agent.
However, thyroid function can be evaluated
after use of these agents by using T3
resin uptake and total or free thyroxine (T4)
assays which are not dependent on iodine
estimations.
Pancreatic Tests
Small quantities of contrast medium in the
intestinal tract may cause false low trypsin
values when determined spectrophotometrically.
Therefore, duodenal instillation
should not precede pancreatic function
tests involving spectrophotometric trypsin
assays.
Any test which might be affected by contrast
media should be performed prior to
administration of the contrast medium.
Carcinogenesis, Mutagenesis,
Impairment of Fertility
Long-term studies in animals have not
been performed to evaluate carcinogenic
or mutagenic potential, or possible
impairment of fertility in males or females.
Pregnancy Category B
When administered intravenously, diatrizoate
salts cross the placenta and are
evenly distributed in fetal tissues.
No teratogenic effects attributable to diatrizoate
meglumine or diatrizoate sodium
have been observed in teratology studies
performed in animals. There are, however,
no adequate and well-controlled studies in
pregnant women. Because small amounts
of these agents may be absorbed, and animal
teratology studies are not always
predictive of human response, these
agents should be used during pregnancy
only when clearly needed.
Procedures including radiation involve a
certain risk related to the exposure of the
fetus.
Nursing Mothers
Diatrizoate meglumine is excreted in
breast milk following intravascular administration.
Because small amounts of enteral gastrointestinal
radiopaque agents may be
absorbed following oral or rectal administration,
caution should be exercised when
they are administered to a nursing
woman.
Pediatric Use
See WARNINGS, and PRECAUTIONS,
General.
Local injury to the colonic mucosa, particularly
in the presence of underlying
disease which interferes with intestial viability,
has been reported in cases where
recommended doses and dilutions (see DOSAGE AND ADMINISTRATION) were
not used; when extemporaneous dosage is
elected, the polysorbate 80 level in the
dose may be a contributing factor to
injury.
Adverse Reactions
Most adverse reactions to enteral diagnostic
radiopaque agents are mild and
transitory. Nausea, vomiting and/or diarrhea,
urticaria with erythema, hypoxia,
acute dyspnea, tachyarrhythmia, and anaphylaxis
have occurred following ingestion
of the contrast medium, particularly when
high concentrations of large volumes of
solution are administered. Severe changes
in serum osmolarity and electrolyte concentrations
may produce shock-like states
(see WARNINGS). It should be kept in mind
that serious or anaphylactoid reactions
that may occur with intravascular administration
of radiopaque contrast agents are
theoretically possible following administration
by other routes.
Overdosage
See WARNINGS regarding potential
hypovolemia, hypotension, or shock. The
maintenance of an open intravenous fluid
line for rehydration may be advisable. See DOSAGE AND ADMINISTRATION for
appropriate doses and dilutions. Treatment
of an overdose should be directed toward
the support of all vital functions, and
prompt institution of symptomatic
therapy.
Gastrografin Dosage and Administration
General
This medium is not to be used for the
preparation of solutions for parenteral
administration. Oral or rectal administration
only.
The routine preparatory measures
employed for barium studies are also
appropriate for this agent.
For pediatric and severely cachectic
patients the maintenance of an intravenous
fluid line may be advisable.
Radiographic Examination of
Segments of the Gastrointestinal Tract
Oral Administration: Adult oral dosage may
range from 30 to 90 mL (11 to 33 g iodine),
depending on the nature of the examination
and the size of the patient. For infants
and children less than 5 years of age,
30 mL (11 g iodine) are usually adequate;
for children 5 to 10 years of age, the suggested
dose is 60 mL (22 g iodine). These
pediatric doses may be diluted 1:1, if
desired, with water, carbonated beverage,
milk, or mineral oil. When used in infants,
the solution may be given in a nursing
bottle. Pediatric doses may also be used
in dehydrated and/or debilitated adult
patients. A 1:1 dilution is also recommended
when the contrast medium is
used in elderly cachectic individuals.
For very young (under 10 kg) and debilitated
children the dose should be diluted:
1 part Gastrografin (Diatrizoate Meglumine
and Diatrizoate Sodium Solution) in 3 parts
water is recommended.
For Enemas or Enterostomy Instillations:
Gastrografin should be diluted when it is
used for enemas and enterostomy instillations.
When used as an enema, the
suggested dilution for adults is 240 mL
(88 g iodine) in 1,000 mL of tap water. For
children under 5 years of age, a 1:5 dilution
in tap water is suggested; for children over
5 years of age, 90 mL (33 g iodine) in
500 mL of tap water is a suitable dilution.
Tomography (Body Imaging)
A usual adult dose is 240 mL of a dilute
Gastrografin solution prepared by diluting
25 mL (9.17 g iodine) to one liter with tap
water. Less dilute solutions [up to 77 mL
(28.26 g iodine) diluted to one liter with tap
water] may be used when indicated. The dose is administered orally about 15 to
30 minutes prior to imaging in order to permit
the contrast medium to reach the
pelvic loops.
How is Gastrografin Supplied
Gastrografin (Diatrizoate Meglumine
and Diatrizoate Sodium Solution USP)
is available in packages of:
Twenty-four 30 mL single dose bottles
(NDC 0270-0445-35).
Twelve 120 mL bottles
(NDC 0270-0445-40).
Storage
Protect from light. Store at 20-25°C (68-77°F)
[See USP]; avoid excessive heat.
Manufactured for
Bracco Diagnostics Inc.
Princeton, NJ 08543
by Therapex, Division of E-Z-EM Canada, Inc.
Anjou, Quebec H1J 2Z4, Canada
REV. 02/05
CW1336-2
| Gastrografin (diatrizoate meglumine and diatrizoate sodium) |
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Revised: 10/2006
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