MD-76R (Diatrizoate Meglumine / Diatrizoate Sodium) - Indications and Dosage

INDICATIONS AND USAGE

MD-76R is indicated in excretion urography, aortography, pediatric angiocardiography, peripheral arteriography, selective renal arteriography, selective visceral arteriography, selective coronary arteriography with or without left ventriculography, contrast enhancement of computed tomographic brain imaging and for intravenous digital subtraction angiography.

MD-76R is also indicated for the contrast enhancement in body computed tomography. (See Clinical Pharmacology). Continuous or multiple scans separated by intervals of 1-3 seconds during the first 30-90 seconds post-injection of the contrast medium (dynamic CT scanning) provide enhancement of diagnostic significance. Subsets of patients in whom delayed body CT scans might be helpful have not been identified. Inconsistent results have been reported and abnormal and normal tissues may be isodense during the time frame used for delayed CT scanning. The risks of such indiscriminate use of contrast media are well known and such use is not recommended. At present, consistent results have been documented using dynamic CT techniques only.

DOSAGE AND ADMINISTRATION

MD-76R should be at body temperature when injected, and may need to be warmed before use. If kept in a syringe for prolonged periods before injection, it should be protected from exposure to strong light.

The patient should be instructed to omit the meal that precedes the examination. Appropriate premedication, which may include a barbiturate, tranquilizer or analgesic drug, may be administered prior to the examination.

A preliminary film is recommended to check the position of the patient and the x-ray exposure factors.

If during administration a minor reaction occurs, the injection should be slowed or stopped until the reaction has subsided. If a major reaction occurs the injection should be discontinued immediately.

Under no circumstances should either corticosteroids or antihistamines be mixed in the same syringe with the contrast medium because of a potential for chemical incompatibility.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration.

EXCRETORY UROGRAPHY

Following intravenous injection, MD-76R is rapidly excreted by the kidneys. MD-76R may be visualized in the renal parenchyma 30 seconds following bolus injection. Maximum radiographic density in the calyces and pelves occurs in most instances within 3-8 minutes after injection. In patients with severe renal impairment, contrast visualization may be substantially delayed.

Patient Preparation

Appropriate preparation of the patient is important for optimal visualization. A low residue diet is recommended for the day preceding the examination and a laxative is given the evening before the examination, unless contraindicated.

Precautions

In addition to the general precautions previously described, infants and young children should not have any fluid restrictions prior to excretory urography. Injection of MD-76R represents an osmotic load which, if superimposed on increased serum osmolality due to partial dehydration, may magnify hypertonic dehydration. (See WARNINGS and PRECAUTIONS, General concerning preparatory dehydration.)

Usual Dosage

The dose range for adults is 20 to 40 mL; the usual dose is 20 mL; children require proportionately less. Suggested dosages are as follows: under 6 months of age – 4 mL; 6 to 12 months – 6 mL; 1 to 2 years – 8 mL; 2 to 5 years – 10 mL; 5 to 7 years – 12 mL; 8 to 10 years – 14 mL; 11 to 15 years – 16 mL. In adults, when the smaller dose has provided inadequate visualization, or when poor visualization is anticipated, the 40 mL dose may be given.

The preparation is given by intravenous injection. If flushing or nausea occur during administration, injection should be slowed or briefly interrupted until the side effects have disappeared.

INTRAVENOUS DIGITAL SUBTRACTION ANGIOGRAPHY

Digital subtraction angiography (DSA) is a radiographic modality which allows dynamic imaging of the arterial system following intravenous injection of iodinated x-ray contrast media through the use of image intensification, enhancement of the iodine signal and digital processing of the image data. Temporal subtraction of the images obtained during the “first arterial pass” of the injected contrast medium from images obtained before and after contrast medium injection yield images which are devoid of bone and soft tissue.

Areas that have been most frequently examined by intravenous DSA are the heart, including coronary by-pass grafts; the pulmonary arteries; the arteries of the brachiocephalic circulation; the aortic arch; the abdominal aorta and its major branches including the celiac, mesenterics and renal arteries; the iliac arteries; and the arteries of the extremities.

Patient Preparation

No special patient preparation is required for DSA. However, it is advisable to insure that patients are well hydrated prior to examination.

Precautions

In addition to the general precautions previously described, the risks associated with DSA are those usually attendant with catheter procedures and include intramural injections, vessel dissection and tissue extravasation. Small test injections of contrast medium made under fluoroscopic observation to insure the catheter tip is properly positioned, and in the case of peripheral placement that the vein is of adequate size, will reduce this potential.

Patient motion, including respiration and swallowing, can result in marked image degradation yielding non-diagnostic studies. Therefore, patient cooperation is essential.

Adverse Reactions

See section on ADVERSE REACTIONS, General.

Usual Dosage

MD-76R may be injected either centrally, into the superior or inferior vena cava, or peripherally into an appropriate arm vein. For central injections, catheters may be introduced at the antecubital fossa into either the basilic or cephalic vein or at the leg into the femoral vein and advanced to the distal segment of the corresponding vena cava.

For peripheral injections, the catheter is introduced at the antecubital fossa into an appropriate size arm vein. In order to reduce the potential for extravastion during peripheral injection, a catheter of approximately 20 cm in length should be employed.

Depending on the area to be imaged, the usual dose range is 20-60 mL. Injections may be repeated as necessary.

Central catheter injections are usually made with a power injector with an injection rate of between 10 and 30 mL/second. When making peripheral injections, rates of 12 to 20 mL/second should be used, depending on the size of the vein. Also, since contrast medium may remain in the arm vein for an extended period following injection, it may be advisable to flush the vein, immediately following injection with an appropriate volume (20-25 mL) of 5% Dextrose in water or normal saline.

HOW SUPPLIED

MD-76 ® R Glass Vials/Bottles	NDC Number
50x50 mL vials	0019-1317-15
12x100 mL bottles	0019-1317-07
12x150 mL bottles	0019-1317-11
12x200 mL bottles	0019-1317-09
ULTRAJECT ® Delivery System MD-76 ® R Prefilled Plastic Syringes
20x125 mL power Injector syringes	0019-1317-81

Storage: Store below 30°C (86°F). Exposing this product to very cold temperatures may result in crystallization of the salt. If this occurs the container should be brought to room temperature. Shake vigorously to assure complete dissolution of any crystals. The speed of dissolution may be increased by heating with circulating warm air. Submersion of syringes in water is not recommended. Before use, examine the product to assure that all solids are redissolved and that the container and closure have not been damaged. This preparation is sensitive to light and must be protected from strong daylight or direct exposure to the sun.

Do not reautoclave plastic container because of possible damage to syringe.

As with all contrast media, glass and plastic containers should be inspected prior to use to ensure that breakage or other damage has not occurred during shipping and handling. All containers should be inspected for closure integrity. Damaged containers should not be used.