DOSAGE AND ADMINISTRATION
It is advisable that HEXABRIX be at or close to body temperature when injected.
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 prior to the injection of the contrast medium.
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 other drugs be administered concomitantly in the same syringe or IV administration set because of a potential for chemical incompatibility.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration.
HEXABRIX may be administered by catheter injection into the chambers of the heart or associated large blood vessels. Rapid injection is essential and satisfactory results usually require injection of the total dosage in 1-2 seconds.
In addition to the general precautions previously described, it is advisable to monitor for ECG and vital signs changes throughout the procedure.
When large individual doses are administered sufficient time should be allowed for any observed changes to return to or near baseline prior to making the next injection.
Caution should be used when making right heart injections in patients with pulmonary hypertension or incipient heart failure since this may lead to increased right side pressures with subsequent bradycardia and systemic hypotension. Patients with pulmonary disease present additional risks.
Caution is advised in cyanotic infants since apnea, bradycardia, other arrhythmias and a tendency to acidosis are more likely to occur.
Since infants are more likely to respond with convulsions than are adults, the amount of total dosage is of particular importance. Repeated injections are hazardous in infants weighing less than 7 kg, particularly when these infants have pre-existing compromised right heart function or obliterated pulmonary vascular beds.
In addition to the adverse reactions previously listed, this procedure has been complicated by intramural injection with marked adverse effects on cardiac function.
The volume of individual doses should be determined by the size of the structure to be visualized and the anticipated degree of hemodilution at the site of injection. Valvular competence should also be taken into consideration.
Older Children: Catheter angiocardiography usually requires single doses of 30-45 mL of HEXABRIX.
Infants and Young Children: The recommended single dose of HEXABRIX is about 1.5 mL/kg (range 1 mL/kg to 2 mL/kg). In addition, small test volumes of about 2 mL may be used for catheter placement.
The usual total dose of HEXABRIX per procedure, which includes diagnostic and test doses is about 4 mL/kg. This dosage may be as small as 1.5 mL/kg and should not normally exceed 5 mL/kg.