Indications & Uses
Diapac is used in adults for angiocardiography, aortography, intravenous digital subtraction angiography of the head, neck, and abdominal, renal, and peripheral vessels, peripheral arteriography, and excretory urography. In children, it is used for angiocardiography.
Dosage Reference
Reference Information Only
Dosages shown are general references from official sources. Always consult your doctor or pharmacist for personalized dosing.
Adults:
Ventriculography, adults: The usual adult volume for a single injection is 40 mL, with a range of 30 mL to 60 mL. This may be repeated as necessary. When combined with selective coronary arteriography, the total administered volume should not exceed 250 mL (87.5 g iodine). Pediatrics: The usual single injection dose of Iohexol 350 is 1.25 mL per kg of body weight, with a range of 1 mL/kg to 1.5 mL/kg. When multiple injections are given, the total administered dose should not exceed 5 mL/kg, up to a total volume of 250 mL of Iohexol 350. Selective coronary arteriography: The usual adult volume for right or left coronary arteriography is 5 mL, with a range of 3 mL to 14 mL, per injection. Aortic root and arch study when used alone: The usual adult single injection volume is 50 mL, with a range of 20 mL to 75 mL. Pulmonary angiography, pediatrics: The usual single injection dose is 1 mL/kg of Iohexol 350. Combined angiocardiographic procedures, multiple procedures. Adults: The maximum total volume for multiple procedures should not exceed 250 mL of 350 mg iodine/mL. Pediatrics: The maximum total dose for multiple injection procedures should not exceed 5 mL/kg, up to a total volume of 250 mL of Iohexol. Aortography and selective visceral arteriography, adults: The usual adult volume as a single injection is 50 mL to 80 mL for the aorta, 30 mL to 60 mL for major branches including the celiac and mesenteric arteries, and 5 mL to 15 mL for the renal arteries. Repeated injections may be performed if indicated, but the total volume should not exceed 250 mL of Iohexol 350. Pediatrics: The usual single injection dose is 1.0 mL/kg of Iohexol 350 and should not exceed 5.0 mL/kg, up to a total volume of 250 mL of Iohexol 350. CT scanning of the body. Head imaging by injection: 80 mL (28 gI) of Iohexol 350 (350 mgI/mL). Body imaging by injection: 60 mL to 100 mL (21 gI to 35 gI) of Iohexol 350 (350 mgI/mL). Digital subtraction angiography, intravenous administration: The usual injection volume of Iohexol 350 for the intravenous digital technique is 30 mL to 50 mL. This is administered as a bolus at 7.5 to 30 mL per second using a pressure injector. The volume and rate of injection will depend primarily on the type of equipment and technique used. Frequently, three or more injections may be required, up to a total volume not to exceed 250 mL (87.5 g iodine). Peripheral angiography: The volume required will depend on the size, flow rate, and disease state of the injected vessel and on the size and condition of the patient, as well as the imaging technique used. The dosage recommended for use in peripheral angiography is as follows. Aortofemoral runoffs: 20 mL to 70 mL of Iohexol 350 (350 mgI/mL). Selective arteriograms (femoral/iliac): 10 mL to 30 mL of Iohexol 350 (350 mgI/mL). Excretory urography, adults: Iohexol 350 at dosages from 200 mg iodine/kg body weight to 350 mg iodine/kg body weight have produced diagnostic opacification of the excretory system in patients with normal renal function.
Side Effects
Cardiovascular System: Irregular heartbeats, including PVCs (premature ventricular contractions) and PACs (premature atrial contractions), occurred in about 2% of patients, along with angina or chest pain (1%) and low blood pressure (0.7%). Less commonly (0.3% or fewer in each case), heart failure, asystole, slow or fast heart rate, and vasovagal reactions were reported. Nervous System: Vertigo, including dizziness and lightheadedness, occurred in 0.5% of patients, along with pain (3%), vision changes such as blurred vision and photomas (2%), headache (2%), and a distorted sense of taste (1%). Less commonly (0.3% or fewer in each case), anxiety, fever, problems with movement or speech, convulsions, paresthesia (tingling or numbness), drowsiness, neck stiffness, hemiparesis (weakness on one side of the body), fainting, shivering, transient ischemic attack (mini-stroke), cerebral infarction (stroke), and nystagmus (involuntary eye movement) were reported. Respiratory System: Breathlessness, runny nose, coughing, and laryngitis were each reported in 0.2% or fewer patients. Gastrointestinal System: Nausea (2%) and vomiting (0.7%). Less commonly, diarrhea, indigestion, cramps, and dry mouth were reported, each in under 0.1% of patients. Skin and Appendages: Hives (0.3%), purpura (0.1%), abscess (0.1%), and itching (0.1%). In children (Pediatrics), the following reactions were reported. Cardiovascular System: Ventricular tachycardia (0.5%), 2:1 heart block (0.5%), high blood pressure (0.3%), and anemia (0.3%). Nervous System: Pain (0.8%), fever (0.5%), altered taste (0.5%), and convulsions (0.3%). Respiratory System: Congestion (0.3%) and apnea, or temporary pauses in breathing (0.3%). Gastrointestinal System: Nausea (1%), low blood sugar (0.3%), and vomiting (2%). Skin and Appendages: Rash (0.3%).
Cautions & Contraindications
Warnings & Precautions
After parenteral administration of a radiopaque agent, competent personnel and emergency facilities should be available for at least 30 to 60 minutes, since severe delayed reactions have occurred. Preparatory dehydration is dangerous and may contribute to acute renal failure in patients with advanced vascular disease, diabetic patients, and susceptible non-diabetic patients (often elderly with preexisting renal disease), infants, and small children. Patients should be well hydrated before and after administration of any contrast medium, including Diapac. Acute renal failure has been reported in diabetic patients with diabetic nephropathy and in susceptible non-diabetic patients following excretory urography. Therefore, the potential risks should be carefully weighed before performing this radiographic procedure in these patients. Immediately following surgery, excretory urography should be used with caution in renal transplant recipients. A positive history of allergies or hypersensitivity does not automatically rule out the use of a contrast agent when a diagnostic procedure is considered essential, but caution should be exercised. Premedication with antihistamines or corticosteroids to avoid or minimize possible allergic reactions in such patients should be considered and given using separate syringes. Even though the osmolality of Diapac is low compared with diatrizoate or iothalamate based ionic agents of comparable iodine concentration, the potential transient increase in circulatory osmotic load in patients with congestive heart failure calls for caution during injection. These patients should be observed for several hours after the procedure to detect delayed hemodynamic disturbances. General anesthesia may be indicated for some procedures in selected adult patients. However, a higher incidence of adverse reactions has been reported in these patients, which may be attributable to the patient's inability to recognize untoward symptoms, or to the hypotensive effect of anesthesia, which can reduce cardiac output and prolong the duration of exposure to the contrast agent. Angiography should be avoided whenever possible in patients with homocystinuria, because of the risk of inducing thrombosis and embolism. During angiographic procedures, the possibility of dislodging plaques or damaging or perforating the vessel wall should be kept in mind during catheter manipulation and contrast medium injection. Test injections to confirm proper catheter placement are recommended. Selective coronary arteriography should be performed only in patients in whom the expected benefits outweigh the potential risk. The inherent risks of angiocardiography in patients with chronic pulmonary emphysema must be weighed against the need to perform the procedure. When Diapac is injected using plastic disposable syringes, the contrast medium should be drawn into the syringe and used immediately. If nondisposable equipment is used, scrupulous care should be taken to prevent residual contamination with traces of cleansing agents. Parenteral products should be inspected visually for particulate matter and discoloration before administration. If particulate matter or discoloration is present, the product should not be used.
Contraindications
Iohexol should not be given to anyone who has previously shown a hypersensitivity reaction to it.