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 pre-existing cyanosis was transiently intensified following contrast media administration. In the second patient pre-existing 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 (Iopamidol 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.

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 arteriographyand 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 (Iopamidol 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 pre-existing 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 Iopamidol: Cardiovascular: arrhythmia, arterial spasms, flushing, vasodilation, chest pain, cardiopulmonary arrest; Nervous System: 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.