Adverse reactions following the use of iopamidol are usually mild to moderate, self-limited, and transient.
In angiocardiography (597 patients), the adverse reactions with an estimated incidence of one percent or higher are: hot flashes 3.4%; angina pectoris 3.0%; flushing 1.8%; bradycardia 1.3%; hypotension 1.0%; hives 1.0%.
In a clinical trial with 76 pediatric patients undergoing angiocardiography, 2 adverse reactions (2.6%) both remotely attributed to the contrast media were reported. Both patients were less than 2 years of age, both had cyanotic heart disease with underlying right ventricular abnormalities and abnormal pulmonary circulation. In one patient preexisting cyanosis was transiently intensified following contrast media administration. In the second patient preexisting decreased peripheral perfusion was intensified for 24 hours following the examination. (See “PRECAUTIONS” Section for information on high risk nature of these patients.)
Intravascular injection of contrast media is frequently associated with the sensation of warmth and pain especially in peripheral arteriography and venography; pain and warmth are less frequent and less severe with ISOVUE (lopamidol Injection) than with diatrizoate meglumine and diatrizoate sodium injection.
The following table of incidence of reactions is based on clinical studies with ISOVUE in about 2246 patients.
|Estimated Overall Incidence|
|System||> 1%||≤ 1%|
S-T segment depression
transient ischemic attack
burning sensation (1.4%)
tingling in arms
|Skin and Appendages||none||rash|
|Body as a Whole||hot flashes (1.5%)||headache|
|Special Senses||warmth (1.1%)||taste alterations|
Regardless of the contrast agent employed, the overall estimated incidence of serious adverse reactions is higher with coronary arteriography than with other procedures. Cardiac decompensation, serious arrhythmias, or myocardial ischemia or infarction have been reported with Isovue and may occur during coronary arteriography and left ventriculography.
Following coronary and ventricular injections, certain electrocardiographic changes (increased QTc, increased R-R, T-wave amplitude) and certain hemodynamic changes (decreased systolic pressure) occurred less frequently with ISOVUE (lopamidol Injection) than with diatrizoate meglumine and diatrizoate sodium injection; increased LVEDP occurred less frequently after ventricular iopamidol injections.
In aortography, the risks of procedures also include injury to the aorta and neighboring organs, pleural puncture, renal damage including infarction and acute tabular necrosis with oliguria and anuria, accidental selective filling of the right renal artery during the translumbar procedure in the presence of preexisting renal disease, retroperitoneal hemorrhage from the translumbar approach, and spinal cord injury and pathology associated with the syndrome of transverse myelitis.
The following adverse reactions have been reported for lopamidol: Cardiovascular: arrhythmia, arterial spasms, flushing, vasodilation, chest pain, cardiopulmonary arrest; Nervous: confusion, paresthesia, dizziness, temporary cortical blindness, temporary amnesia, convulsions, paralysis, coma; Respiratory: increased cough, sneezing, asthma, apnea, laryngeal edema, chest tightness, rhinitis; Skin and Appendages: injection site pain usually due to extravasation and/or erythematous swelling, pallor, periorbital edema, facial edema; Urogenital: pain, hematuria; Special Senses: watery itchy eyes, lacrimation, conjunctivitis; Musculoskeletal: muscle spasm, involuntary leg movement; Body as a whole: tremors, malaise, anaphylactoid reaction (characterized by cardiovascular, respiratory and cutaneous symptoms), pain; Digestive: severe retching and choking, abdominal cramps. Some of these may occur as a consequence of the procedure. Other reactions may also occur with the use of any contrast agent as a consequence of the procedural hazard; these include hemorrhage or pseudoaneurysms at the puncture site, brachial plexus palsy following axillary artery injections, chest pain, myocardial infarction, and transient changes in hepatorenal chemistry tests. Arterial thrombosis, displacement of arterial plaques, venous thrombosis, dissection of the coronary vessels and transient sinus arrest are rare complications.
General Adverse Reactions To Contrast Media
Reactions known to occur with parenteral administration of iodinated ionic contrast agents (see the listing below) are possible with any nonionic agent. Approximately 95 percent of adverse reactions accompanying the use of other water-soluble intravascularly administered contrast agents are mild to moderate in degree. However, life-threatening reactions and fatalities, mostly of cardiovascular origin, have occurred. Reported incidences of death from the administration of other iodinated contrast media range from 6.6 per 1 million (0.00066 percent) to 1 in 10,000 patients (0.01 percent). Most deaths occur during injection or 5 to 10 minutes later, the main feature being cardiac arrest with cardiovascular disease as the main aggravating factor. Isolated reports of hypotensive collapse and shock are found in the literature. The incidence of shock is estimated to be 1 out of 20,000 (0.005 percent) patients.
Adverse reactions to injectable contrast media fall into two categories: chemotoxic reactions and idiosyncratic reactions. Chemotoxic reactions result from the physicochemical properties of the contrast medium, the dose, and the speed of injection. All hemodynamic disturbances and injuries to organs or vessels perfused by the contrast medium are included in this category.
Experience with iopamidol suggests there is much less discomfort (e.g. pain and/or warmth) with peripheral arteriography. Fewer changes are noted in ventricular function after ventriculography and coronary arteriography.
Idiosyncratic reactions include all other reactions. They occur more frequently in patients 20 to 40 years old. Idiosyncratic reactions may or may not be dependent on the amount of drug injected, the speed of injection, the mode of injection, and the radiographic procedure.
Idiosyncratic reactions are subdivided into minor, intermediate, and severe. The minor reactions are self-limited and of short duration; the severe reactions are life-threatening and treatment is urgent and mandatory.
The reported incidence of adverse reactions to contrast media in patients with a history of allergy is twice that for the general population. Patients with a history of previous reactions to a contrast medium are three times more susceptible than other patients. However, sensitivity to contrast media does not appear to increase with repeated examinations. Most adverse reactions to intravascular contrast agents appear within one to three minutes after the start of injection, but delayed reactions may occur. Delayed reactions, usually involving the skin, may uncommonly occur within 2-3 days (range 1-7 days) after the administration of contrast (see PRECAUTIONS-General). Delayed allergic reactions are more frequent in patients treated with immunostimulants, such as interleukin-2.
In addition to the adverse drug reactions reported for iopamidol, the following additional adverse reactions have been reported with the use of other intravascular contrast agents and are possible with the use of any water-soluble iodinated contrast agent:
Cardiovascular: cerebral hematomas, petechiae; Hematologic: neutropenia; Skin and Appendages: skin necrosis; Urogenital: osmotic nephrosis of proximal tubular cells, renal failure; Special Senses: conjunctival chemosis with infection.