SIDE EFFECTS
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.
Adverse Reactions
System |
> 1% |
≤ 1% |
Cardiovascular |
none |
tachycardia
hypotension
hypertension
myocardial ischemia
circulatory collapse
S-T segment depression
bigeminy
extrasystoles
ventricular fibrillation
angina pectoris
bradycardia
transient ischemic attack
thrombophlebitis |
Nervous |
pain (2.8%) |
vasovagal reaction
tingling in arms
grimace
faintness |
burning sensation (1.4%) |
Digestive |
nausea (1.2%) |
vomiting
anorexia |
Respiratory |
none |
throat constriction
dyspnea
pulmonary edema |
Skin and Apper |
idages none |
rash
urticaria
pruritus
flushing |
Body as a Whole |
hot flashes (1.5%) |
headache
fever
chills
excessive sweating
back spasm |
Special Senses |
warmth (1.1%) |
taste alterations
nasal congestion
visual disturbances |
Urogenital |
none |
urinary retention |
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 (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.
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. 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; Urogenital: osmotic nephrosis of proximal tubular cells,
renal failure; Special Senses: conjunctival chemosis with infection. Endocrine:
Thyroid function tests indicative of hypothyroidism or transient thyroid
suppression have been uncommonly reported following iodinated contrast media
administration to adult and pediatric patients, including infants. Some
patients were treated for hypothyroidism. Skin and Subcutaneous Tissue
Disorders: Skin necrosis; Reactions range from mild (e.g. rash, erythema,
pruritus, uticaria and skin discoloration) to severe: [e.g. Stevens-Johnson
syndrome and toxic epidermal necrolysis (SJS/TEN), cute generalized
exanthematous pustulosis (AGEP) and drug reaction with eosinophilia and systemic
symptoms (DRESS)].