Iopamidol (Systemic)


VA CLASSIFICATION
Primary: DX101

Commonly used brand name(s): Isovue-128; Isovue-200; Isovue-250; Isovue-300; Isovue-370; Isovue-M 200; Isovue-M 300.

Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).



Category:

Note: Iopamidol is a nonionic radiopaque contrast agent. {01} {02}



Diagnostic aid, radiopaque (brain disorders)—

Diagnostic aid, radiopaque (central nervous system disorders)—

Diagnostic aid, radiopaque (cerebrospinal fluid disorders)—

Diagnostic aid, radiopaque (cardiac disease)—

Diagnostic aid, radiopaque (vascular disease)—

Diagnostic aid, radiopaque contrast enhancer in computed tomography—

Diagnostic aid, radiopaque (peritoneal disorders)—

Diagnostic aid, radiopaque (urinary tract disorders)—

Diagnostic aid, radiopaque (joint disease)—

Diagnostic aid, radiopaque (biliary tract disorders)—

Indications

Note: Bracketed information in the Indications section refers to uses that are not included in U.S. product labeling.

Accepted

Intrathecal
Myelography (lumbar, thoracic1 , cervical1 , total columnar1 )—Iopamidol is indicated for lumbar, thoracic, cervical, and total columnar myelography (standard or computed tomographic) to determine the presence of abnormalities in the spinal column, spinal canal, and the central nervous system (CNS). {01} {02} {39} {77} {79}

Cisternography, computed tomographic (CT)1—Iopamidol is indicated in adults for computerized tomography of the intracranial subarachnoid spaces. {01} {77}

Intravascular
Angiocardiography—Iopamidol is indicated for angiocardiography (selective coronary arteriography or ventriculography) to visualize lesions or malformations of the heart and obstructions or anomalies of the major thoracic vessels. {01} {02} {20} {21} {36}

Angiography or
Aortography1 or
Arteriography or
Venography—Iopamidol is indicated in adults to visualize specific regions of the vascular system and blood flow in such areas to help in the diagnosis and evaluation of neoplasms (known or suspected) or vascular diseases (congenital or acquired) that may cause changes in normal vascular anatomy or physiology. It is indicated for use in intra-arterial digital subtraction angiography; cerebral, peripheral, or selective visceral1 arteriography; aortography; and peripheral venography (phlebography). In cerebral arteriography, iopamidol is indicated to determine the presence and extent of certain neoplasms (e.g., gliomas, pituitary adenomas, metastatic lesions) and non-neoplastic lesions, such as cerebral infarctions, arteriovenous malformations, and aneurysms1 . {01} {02} {20} {36} {45} {75} {76}

Brain imaging, computed tomographic—Iopamidol is indicated for enhancement of computed tomographic images of the brain (CT of the brain) to determine the presence and extent of neoplasms or other lesions such as cerebral infarction or infection. {01} {76} {79}

Body imaging, computed tomographic—Iopamidol is indicated for enhancement of computed tomographic images of the body (CT of the body) for detection and evaluation of lesions in the liver, pancreas, kidneys, aorta, mediastinum, abdominal cavity, pelvis, and retroperitoneal space. {01} {76} {79}

Urography, excretory—Iopamidol is indicated in intravenous excretory urography to evaluate abnormalities of the urinary tract such as urinary tract obstruction. {01} {02} {05} {76} {79}

[Herniography]1—Iopamidol is used in herniography in adults. {43} {46}

Intraductal
[Pancreatography, endoscopic retrograde]1and
[Cholangiopancreatography, endoscopic retrograde]1—Iopamidol is used in adults in endoscopic retrograde pancreatography and endoscopic retrograde cholangiopancreatography for visualization of all portions of the biliary tree. {43} {46}

Intrasynovial
[Arthrography]1—Iopamidol is used for arthrography in the diagnosis of post-traumatic or degenerative joint diseases or synovial rupture, for visualization of communicating bursae or cysts, and in meniscography. {43} {46}

1 Not included in Canadian product labeling.



Pharmacology/Pharmacokinetics

Physicochemical characteristics:
Molecular weight—
    777.09


Osmolality
    Low. The osmolalities of the injections of iopamidol with iodine concentrations of 200, 300, and 370 mg per mL are 413, 616, and 796 mOsmol per kg of water, respectively {01}

Note: Iopamidol injection is hypertonic as compared to plasma and cerebrospinal fluid (approximately 265 and 301 mOsmol per kg of water, respectively). {01}


Mechanism of action/Effect:

Organic iodine compounds block x-rays as they pass through the body, thereby allowing body structures containing iodine to be delineated in contrast to those structures that do not contain iodine. {53} The degree of opacity produced by these compounds is directly proportional to the total amount (concentration and volume) of the iodinated contrast agent in the path of the x-rays. After intrathecal administration into the subarachnoid space, diffusion of iopamidol in the CSF allows the visualization of the subarachnoid spaces of the head and spinal canal. After intravascular administration, iopamidol makes opaque those vessels in its path of flow, allowing visualization of the internal structures until significant hemodilution occurs. {01} {22} {23} {45} {46}

Distribution:

Intrathecal—Diffuses upward through the CSF; penetrates into nerve root sleeves, nerve rootlets, and narrow areas of the subarachnoid space. Also, enters extracellular fluid of the brain tissue and pial surface of cerebral and cerebellar tissue adjacent to subarachnoid areas. In patients with normal CSF dynamics, it is eliminated from CSF into the blood within 1 hour. {01} {77}

Intravascular—Rapidly distributed throughout circulating blood volume and diffused into extravascular space following intravenous administration. No significant deposition in tissues. Does not cross blood-brain barrier, but accumulates within the interstitial tissues of malignant tumors of the brain due to the break in the blood-brain barrier caused by the tumor. {01} {02} {79}

Protein binding:

Very low. {01} {77} {79}

Half-life:

Elimination—Intravascular: Approximately 2 hours (with normal renal function). {01} {02} {79}


Time to peak opacification:


Standard myelography:

Immediate and for up to 30 minutes. {77} {79}



CT myelography:

4 hours.



Intravascular:

5 to 40 minutes.

Urography: 5 to 15 minutes.


Peak serum concentration:

Intravascular—Immediate, but concentration falls rapidly as iopamidol becomes distributed throughout the extravascular compartment. {76} {79}

Elimination:
    Intrathecal—Primarily renal; 29 to 100% of administered dose excreted unchanged within 48 hours. {79}
    Intravascular—Primarily renal; 35 to 40% of administered dose excreted unchanged within 1 hour, and 80 to 90% in 8 hours. {01} {77}

Note: In patients with impaired renal function, the excretion of iopamidol is prolonged depending upon the degree of impairment. {01} {02}



Precautions to Consider

Cross-sensitivity and/or related problems

Patients sensitive to iodine or other iodinated contrast media may be sensitive to iopamidol also. {01} {24} {45}

Mutagenicity

Animal studies to evaluate mutagenic potential of iopamidol have not shown that iopamidol causes any increase in mutation rates. {01} {75}

Pregnancy/Reproduction

Pregnancy—
Adequate and well-controlled studies in humans have not been done. However, other organically bound iodine–containing preparations administered near term by intra-amniotic injection have caused hypothyroidism in some newborns. {04} {45}

Also, elective contrast radiography of the abdomen is usually not recommended during pregnancy because of the risks to the fetus from radiation exposure.

Teratology studies in animals have not shown that iopamidol causes harm to the fetus.

FDA Pregnancy Category B. {01} {75} {77}

Breast-feeding

It is not known whether iopamidol is distributed into breast milk. However, because other contrast media are distributed unchanged into breast milk, temporary discontinuation of breast-feeding is recommended for at least 24 hours following administration of iopamidol. {01} {45}

Pediatrics

Appropriate studies on the relationship of age to the effects of iopamidol have not been performed in pediatric patients. However, it is known that pediatric patients, especially those with asthma, allergies, congestive heart failure, or serum creatinine greater than 1.5 mg per dL or those less than 12 months of age, exhibit an increased risk of having severe adverse effects to radiopaque contrast media. {01} {46} {79}

Also, in infants and young children, especially those with polyuria, oliguria, diabetes, or pre-existing dehydration, dehydration and/or the risk of renal failure may be exacerbated by the radiopaque contrast media; adequate hydration is recommended before and following intravascular administration of iopamidol. {01} {46} {53}


Geriatrics


Diagnostic studies performed to date have not demonstrated geriatrics-specific problems that would limit the usefulness of iopamidol in the elderly. However, elderly patients are more likely to have age-related renal function impairment, which may require lower dosage in patients receiving iopamidol. {20} {21}

Dehydration and/or the risk of renal failure may be exacerbated in geriatric patients, especially those with polyuria, oliguria, diabetes, or pre-existing dehydration, by iopamidol; adequate hydration is recommended before and following administration of iopamidol. {01}

The elderly may be more sensitive to the effects of iopamidol on thyroid function. Iodine-induced thyrotoxicosis may occur 4 to 12 weeks following contrast radiography. Thyroid function monitoring may be needed in geriatric patients. {54}

Drug interactions and/or related problems
The following drug interactions and/or related problems have been selected on the basis of their potential clinical significance (possible mechanism in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):


Note: Combinations containing any of the following medications, depending on the amount present, may also interact with this medication.

» Antidepressants, tricyclic or
CNS stimulation–producing medications (See Appendix II ) or
Monoamine oxidase (MAO) inhibitors, including furazolidone, procarbazine, and selegiline or
» Phenothiazines or
» Trimeprazine    (although this effect has not been specifically reported for iopamidol, concurrent use with intrathecal administration of metrizamide, another nonionic contrast agent, has been associated with increased risk of seizures because of lowered seizure threshold effect of these medications; until more conclusive evidence is available, it is recommended that medications that lower the seizure threshold be discontinued for at least 48 hours before and 24 hours after myelography {01} {45} {46} {77})


Beta-adrenergic blocking agents    (concurrent intravascular administration of iopamidol with beta-adrenergic blocking agents may increase the risk of moderate to severe anaphylactoid reaction; also, hypotensive effects may be exacerbated; discontinuation of the beta-adrenergic blocking agent before administration of contrast media may be advisable in patients with other risk factors {25} {45} {55} {56} {57})


Cholecystographic agents, oral    (may increase the risk of renal toxicity when closely followed by intravascular iopamidol, especially in patients with hepatic function impairment {01} {75} {79})


Hydralazine    (increased risk of systemic lupus erythematosus [SLE]–like syndrome if iopamidol is given to patients on hydralazine therapy {74})


Hypotension-producing medications, other (See Appendix II )    (the risk of severe hypotension may be increased if iopamidol is given concurrently with other medications that produce hypotension {35} {45})


Interleukin-2    (incidence of delayed reactions to intravenous contrast media [e.g., hypersensitivity, fever, skin rash, flu-like symptoms, joint pain, flushing, pruritus, emesis, hypotension, dizziness occurring more than 1 hour after administration] may be increased in patients who have received interleukin-2; some symptoms may resemble a ``recall'' reaction to interleukin-2; supportive medical treatment may be necessary if symptoms are significant; there is some evidence that incidence is reduced if contrast media administration is delayed until 6 weeks after interleukin-2 administration {58} {59} {60} {61} {62} {63})


Nephrotoxic medications, other (See Appendix II )    (concurrent intrathecal or intravascular administration of iopamidol with other nephrotoxic medications may increase the potential for nephrotoxicity {45})


Diagnostic interference
The following have been selected on the basis of their potential clinical significance (possible effect in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):

With other diagnostic test results
Blood pool imaging    (imaging of blood pool may be impaired because of decreased technetium Tc 99m-labeling of red blood cells caused by the intravascular administration of iopamidol {45})


Leukocyte counts and
Red cell counts    (may be temporarily decreased {01})


Prothrombin time (PT) and
Thromboplastin time    (may be increased, since iopamidol has been shown to slightly inhibit all stages of coagulation in in vitro studies with animal blood {01} {45} {75})


Skeletal imaging    (possible renal and hepatic uptake of technetium Tc 99m medronate, technetium Tc 99m oxidronate, technetium Tc 99m pyrophosphate, or technetium Tc 99m [pyro- and trimeta-] phosphates if iopamidol is administered intravenously immediately after one of these technetium Tc 99m-labeled agents {45} {64})


Thyroid function determinations and
Thyroid imaging    (intravascular or intrathecal administration of iopamidol may alter serum protein-bound iodine [PBI] concentrations and radioactive iodine or pertechnetate ion uptake for up to 2 weeks; thyroid test should be performed prior to administration of iopamidol. Other thyroid function tests not based on measurement of iodine, such as resin triiodothyronine uptake, may not be affected {01} {54} {75} {79})


Urinalysis    (iopamidol may interfere with some chemical determinations made on urine, such as protein and specific gravity; urine should be collected prior to, or at least 2 days after, intravascular administration of iopamidol {40})

With physiology/laboratory test values
Creatinine, serum    (concentration may be increased temporarily with iopamidol {01} {21} {45})


Platelet aggregation    (may be decreased by high levels of plasma iopamidol {44})


Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).


Risk-benefit should be considered when the following medical problems exist {01}

For all procedures (especially those requiring intrathecal or intravascular administration):
Allergic reaction (anaphylaxis) to penicillins or to skin allergens, previous    (although the risk of anaphylactoid reaction may be less with iopamidol than with high-osmolality contrast agents, caution is recommended when administering iopamidol to patients who have had a previous reaction to penicillins or to skin allergens {47} {55} {56} {65})


Allergies or asthma, history of    (although the risk of idiosyncratic response or anaphylactoid reaction may be less with iopamidol than with high-osmolality contrast agents, caution is recommended when administering iopamidol to patients with a history of allergies or asthma {25} {47} {55} {56} {65})


» Dehydration, especially associated with pre-existing renal disease, advanced vascular disease, and diabetes mellitus, and in pediatric and elderly patients    (intravascular administration may increase risk of acute renal failure {23} {26} {27} {46} {47})


Renal function impairment, severe    (excretion of iopamidol may be delayed; although the risk of contrast-induced nephrotoxicity with intravascular use in the presence of renal insufficiency [serum creatinine ³ 132.6 micromoles/L] may be less with iopamidol than with high-osmolality contrast agents, caution is recommended {01} {27} {28} {29} {30} {31} {66} {67})


» Sensitivity to iodinated contrast media    (increased risk of anaphylactoid reaction in patients with history of reactions to contrast media {01} {25})


For intrathecal use:
Alcoholism, chronic    (increased risk of side effects because of possible brain or liver damage {45} {77})


Bleeding, subarachnoid    (increased risk of meningeal irritation or arachnoiditis {77})


Epilepsy, history of    (myelographic procedure may increase risk of seizures {01} {45})


Infection, local or systemic, significant{01}{45}{77}
Multiple sclerosis{01}{45}{77}
For intravascular use:
Hyperthyroidism    (administration of iopamidol may precipitate thyroid storm {01})


Pheochromocytoma    (administration of iopamidol may precipitate severe hypertension; amount of iopamidol injected should be kept to a minimum and blood pressure should be monitored during the procedure; also, pretreatment with the alpha-adrenergic blocking agent, phentolamine, is recommended {01} {47} {79})


Sickle cell disease    (administration of iopamidol may promote sickling in patients who are homozygous for sickle cell disease; however, sickling potential of iopamidol is less than that of high-osmolality ionic agents {01} {45})


For angiocardiography:
Angina, unstable    (increased risk of severe cardiac reaction {68})


Cardiac disease    (potential transitory increase in the circulatory osmotic load may aggravate condition {01})


Pulmonary hypertension, severe    (hypervolemic effect of iopamidol may further increase pulmonary artery and venous pressures due to an increase in cardiac output and a rise in left ventricular end-diastolic and left atrial pressures {01} {22} {45} {46})


For cerebral arteriography:
Arteriosclerosis, advanced, or
Cardiac decompensation or
Cerebral embolism, recent or
Hypertension, severe or
Senility or
Thrombosis, recent    (increased risk of vessel occlusion {79})


» Homocystinuria    (procedure may increase risk of thrombosis and embolism {01} {79})


For peripheral arteriography:
» Buerger's disease    (procedure may induce severe arterial or venous spasm {79})


» Ischemia, severe, associated with ascending infection{79}
For excretory urography:
» Anuria or
» Diabetes mellitus    (administration of iopamidol may increase the risk of acute renal failure {01})


For arthrography:
» Infection, in or near joint to be examined    (procedure may increase risk of complications)



Patient monitoring
The following may be especially important in patient monitoring (other tests may be warranted in some patients, depending on condition; » = major clinical significance):


For intravascular use
Blood pressure determinations    (may be required during examination, especially in patients with known or suspected pheochromocytoma or hemodynamic compromise or instability {01} {53})




Side/Adverse Effects

Note: Adverse effects may vary directly with the concentration of the agent, the amount and technique used, and the underlying pathology. Increases in osmolality, volume, concentration, viscosity, and rate of administration of the solution may increase the incidence and severity of adverse effects. {01} {02} {29} {47}
Most of the adverse effects occur soon after administration of contrast media and are usually self-limiting and of short duration. However, some adverse effects may be delayed and may be of a long-lasting nature. {01} {47}
Overall incidence of adverse effects with nonionic contrast agents, such as iopamidol, has been reported to be less than with ionic contrast agents. {02} {30} {47}
Nonionic contrast media, such as iopamidol, have been reported to produce fewer and less severe alterations in cardiac hemodynamics and electrocardiograms than standard ionic contrast agents during cardiac angiography. {01}
Low-osmolality contrast agents, such as iopamidol, are reported to cause less heat and pain on injection than high-osmolality agents, such as diatrizoates and iothalamate. {01} {08} {21}
Thromboembolic events causing myocardial infarction and stroke have been reported during angiographic procedures with nonionic contrast media; however, these events appear to be technique-related. {01} {42} {45} {46}
Headaches following intrathecal administration of iopamidol may be more frequent and persistent in patients not adequately hydrated. {01}
Dehydration and/or the risk of renal failure may be exacerbated by the hypertonic contrast solutions of iopamidol, and in some cases may cause a shock-like state, following intravascular administration of iopamidol in geriatric, azotemic, and dehydrated or debilitated patients. {23}
Transient global amnesia has been reported in 2 patients after cerebral angiography in which 20 mL of another low-osmolality nonionic contrast agent (containing the equivalent of 240 mg of iodine per mL) was administered into the ascending aorta. The possibility that iopamidol may cause a similar response must be considered. {69}

The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:

Those indicating need for medical attention
Incidence rare
With all procedures
    
Pseudo-allergic reaction (skin rash or hives; stuffy nose; swelling of face or skin; wheezing, tightness in chest, or troubled breathing{22}{23}{25}{31}{32}{45}{46}{47})
Note: Pseudo-allergic reactions are usually transient. However, they may be an initial manifestations of a more severe anaphylactoid reaction. The anaphylactoid reaction may progress to respiratory arrest and vasomotor collapse if appropriate treatment is not administered. {56}



With intrathecal or intravascular administration
    
Bronchospasm or pulmonary edema (severe wheezing or troubled breathing{22}{23}{35}{47})
    
hypotension (severe tiredness or weakness)
    
seizures{71}{72}{76}{77}

With intrathecal administration
    
Musculoskeletal effects (involuntary movements; paralysis of legs{01}{33}{77})

With intravascular administration {01}
    
Cardiotoxic effects, with ventricular tachycardia or fibrillation (fast or irregular heartbeat{01}{35}{36}{45}{78})
Note: In angiocardiography, bradyarrhythmias occur far less commonly with low-osmolality contrast agents than with high-osmolality agents. For iopamidol, bradycardia has been reported with an estimated incidence of 1.3%. {01} {68} {70} {76}






Those indicating need for medical attention only if they continue or are bothersome
Incidence more frequent
With intrathecal or intravascular administration
    
Headache, mild to moderate
    
nausea and vomiting, mild to moderate{01}{75}{77}
Note: Headache, nausea, and/or vomiting may occur 1 to 10 hours after intrathecal injection and last for a few hours, usually disappearing within 24 hours; or, less frequently after intravascular injection, may occur immediately and last for a few minutes. {01} {36}



With intrathecal administration
    
Backache
    
dizziness
    
leg pain or cramps
    
meningeal irritation {01}{73}{79}(stiffness of neck)

With intravascular administration
    
Vasodilation, arteriolar (hot flashes or sudden feeling of warmth; pain or burning at injection site, mild{76})


Incidence less frequent or rare
With intrathecal administration
    
CNS effects (severe headache, ringing or buzzing in ears, unusual tiredness or weakness{79})
    
difficult urination
    
drowsiness
    
increased sensitivity of eyes to light
    
increased sweating
    
loss of appetite{79}

With intravascular administration
    
Blurred vision or other changes in vision
    
lightheadedness
    
unusual taste






Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Radiopaque Agents (Diagnostic).

In providing consultation, consider emphasizing the following selected information (» = major clinical significance):

Description of use

Action in the body:
Injection into spinal canal; visualization of radiopacity in head and spinal cord possible with x-rays

Injection into vein or artery; visualization of radiopacity in blood vessels, heart, brain, and other organs possible with x-rays

Direct injection into region to be studied; visualization of joint spaces, peritoneal herniations, pancreatic and bile ducts

Before having this test
»   Conditions affecting use, especially:
Sensitivity to iodine or other iodinated contrast media

Pregnancy—Risk to the fetus from radiation exposure; may cause hypothyroidism in newborn





Breast-feeding—Not known if distributed into breast milk; temporary discontinuation of breast-feeding for at least 24 hours is recommended





Use in children—Increased risk of severe adverse reactions, especially in children with other medical problems; possible exacerbation of dehydration






Use in the elderly—Possible exacerbation of dehydration; increased risk of thyrotoxicosis
Other medications, especially phenothiazines, tricyclic antidepressants, and trimeprazine (with intrathecal administration of iopamidol)
Other medical problems, especially anuria, dehydration, and diabetes mellitus

Preparation for this test
Adequate intake of fluids to prevent dehydration

Special preparatory instructions may be given; patient should inquire in advance

With intrathecal use
Normal diet up to 2 hours before procedure; moderate amounts of clear liquids may be permitted up to time of procedure

Precautions after having this test
Possible interference with future thyroid tests

With intrathecal use
Avoiding movement during and for several hours after administration

Keeping head position as instructed during and after examination


Side/adverse effects
Signs of possible side effects, especially pseudo-allergic reaction and cardiac or pulmonary problems that may occur within minutes of administration


General Dosing Information
Manufacturer's package insert or other appropriate literature should be consulted for specific techniques and procedures for the administration of contrast media.

Sensitivity test doses are not usually recommended since severe or fatal reactions to contrast media are not predictable from a patient's history or a sensitivity test. On some occasions, severe or fatal reactions have occurred with a test dose or with a full dose in patients who did not react to the test dose.

Pretreatment with corticosteroids and/or antihistamines may minimize the incidence and severity of reactions in patients with a history of severe reactions to contrast media or with other high-risk conditions (e.g., asthma or history of allergies, positive allergy history to skin allergens or penicillin, dehydration, history of seizures, pheochromocytoma). {01} In some studies, the additional use of ephedrine has been shown to be beneficial in preventing anaphylactoid reactions (except in patients with a history of hypertension or cardiovascular disease). When considering the use of a contrast agent, the following protocols are recommended: {09} {10} {11} {12} {13} {14} {15} {16} {17} {18} {19} {20} {45} {46} {47} {56} {66} {68} For high-risk patients

   • Use of a high-osmolality contrast agent plus pretreatment with a corticosteroid (oral prednisone, 50 mg administered 13 hours, 7 hours, and 1 hour before procedure) and an antihistamine (intramuscular, intravenous, or oral diphenhydramine, 50 mg administered one hour prior to procedure) or
   • Use of a low-osmolality agent if pretreatment is not feasible or
   • Use of a low-osmolality agent plus corticosteroid pretreatment.
For low-risk patients

   • Use of a high-osmolality contrast agent or
   • Use of a high-osmolality contrast agent and corticosteroid pretreatment.


Adequate hydration is recommended for all patients before and after the examination. Intravenous or oral intake of fluids may continue up to time of administration of iopamidol. {01} {21} {77}

During and for at least 30 to 60 minutes after intravascular injection of iopamidol, and for at least 12 hours (up to 24 hours in some cases) after intrathecal administration, the patient should be observed for possible severe reactions; competent personnel and emergency facilities should be available during this period. {01} {47}

Dosage and concentration of iodine (as iopamidol injection) are dependent upon the degree and extent of contrast needed in the areas under examination and on the equipment and technique used.

For intrathecal use
Pretreatment with barbiturates may be used in patients who have a history of seizures but are not on anticonvulsant therapy. Patients who are on anticonvulsant therapy should continue receiving their medication when using iopamidol. {01}

A normal diet may be ingested up to 2 hours prior to the administration of iopamidol. {01}

If inadvertent intracranial entry of a large or concentrated bolus of iopamidol occurs, treatment with anticonvulsants may be used to minimize the risk of seizures. {01} {71} {72}

Direct intracisternal or ventricular administration of iopamidol for standard radiography is not recommended. {01}

During and for several hours after the procedure the patient must remain inactive to minimize high cephalad dispersion of iopamidol. {01} {77}

Information on patient management and positioning during and after procedure are included in the manufacturer's package insert. {01}

For intravascular use
Nonionic contrast media such as iopamidol inhibit blood coagulation in vitro less than ionic contrast media. Blood cell aggregation has been reported when blood remains in contact with syringes containing nonionic contrast media. Thus, it is possible that thromboembolic events causing myocardial infarction and stroke, reported during angiographic procedures, may have resulted from coagulation of blood that had come in contact with the contrast agent outside the body. It is recommended that risk factors for aggregation be minimized by performing the procedure in the shortest time possible, using plastic rather than glass syringes, and flushing catheters with heparinized saline solutions. {42} {43} {46} {47}

For treatment of adverse effects {25} {37} {38}
Recommended treatment consists of the following:

   • For major or life-threatening reactions, careful monitoring of vital signs and emergency therapy, including artificial respiration with oxygen, if needed for respiratory depression, and cardiac massage in the event of cardiac arrest.
   • To restore blood pressure, administration of intravenous fluids and/or vasopressors. If hypotension necessitates the use of vasopressors, slow infusion of 0.008 to 0.012 mg per minute of norepinephrine or 0.1 to 0.18 mg per minute of phenylephrine, appropriately diluted. If hypotension is due to increased vagal activity (vasovagal reaction), intravenous administration of 1 mg of atropine, repeated in one to two hours if needed.
   • Other specific treatment may include— {55}

• Diphenhydramine: For minor allergic-like reactions—An antihistamine such as diphenhydramine hydrochloride (except in epileptic patients) may be administered intravenously.


• Epinephrine or hydrocortisone: For acute allergic-like or anaphylactoid reactions—Intravenous administration of 500 to 1000 mg of soluble hydrocortisone or slow intravenous infusion of 0.1 mg of epinephrine (1:10,000).For mild to moderate bronchospasm—0.1 to 0.2 mg of epinephrine (1:1000) may be administered subcutaneously, except in hypotension. In extreme emergency, 0.1 mg of epinephrine (1:10,000) may be given slowly by intravenous injection, followed by a continuous intravenous infusion at an initial rate of 0.001 mg per minute; the rate may be increased to 0.004 mg per minute if necessary.Patients on beta-adrenergic blocking agents should not receive epinephrine since they are at risk of excessive alpha-adrenergic stimulation, which may result in hypertension, reflex bradycardia, and heart block. In these patients, isoproterenol and norepinephrine are used instead of epinephrine to overcome bronchospasm and hypotension, respectively.For cardiac arrest—0.1 to 1 mg of epinephrine may be administered by the intravenous route.


• Diazepam or phenobarbital: To control convulsions—5 to 10 mg of diazepam by slow, intravenous administration or phenobarbital sodium intravenously or intramuscularly at a rate not to exceed 30 to 60 mg per minute may be given.



Parenteral Dosage Forms

IOPAMIDOL INJECTION USP

Usual adult and adolescent dose
Intrathecal


Myelography:


Lumbar and Thoracic myelography by lumbar injection1
10 to 15 mL of a solution containing the equivalent of 200 mg of iodine per mL. {77}



Cervical myelography by lumbar injection1
10 to 15 mL of a solution containing the equivalent of 200 mg of iodine per mL; or 10 mL of a solution containing the equivalent of 300 mg of iodine per mL. {77}



Cervical myelography by lateral cervical injection1
10 mL of a solution containing the equivalent of 200 mg of iodine per mL. {77}



Total columnar myelography by lumbar injection1
10 mL of a solution containing the equivalent of 300 mg of iodine per mL. {77}




CT cisternography by lumbar injection1:
4 to 6 mL of a solution containing the equivalent of 200 mg of iodine per mL. {77}

Note: Injection should be administered slowly over a period of 1 to 2 minutes to avoid excessive mixing with cerebrospinal fluid and resultant dilution of iopamidol as well as premature cephalad dispersion. {01} {77}
Immediate repeat intrathecal administration is not recommended because of overdose risk; 48 hours, or preferably 5 to 7 days, should elapse before repeat examination. {77}



Intravascular


Angiography:
Intra-arterial, by digital subtraction—Via catheter, as a solution containing the equivalent of 128 mg of iodine per mL, into the following {46} {75}:

Carotid arteries—6 to 12 mL.

Vertebral arteries—4 to 10 mL.

Aortic arch—25 to 60 mL.

Renal arteries—6 to 15 mL.

Branches of the aorta—12 to 50 mL.

Abdominal aorta—25 to 60 mL.




Arteriography, cerebral:
Carotid puncture or transfemoral catheterization, 8 to 12 mL of a solution containing the equivalent of 300 mg of iodine per mL. {76}



Arteriography, peripheral:
As a solution containing the equivalent of 300 mg of iodine per mL {76}:

Direct injection into the femoral artery or subclavian artery, 5 to 40 mL.

Direct injection into the aorta for distal runoffs, 25 to 50 mL. {76}




Arteriography, selective coronary:
Via catheter, 2 to 10 mL of a solution containing the equivalent of 370 mg of iodine per mL. {76}



Arteriography, selective visceral1:
Via catheter, up to 50 mL into the larger vessels, such as the aorta or celiac artery, or up to 10 mL into the renal arteries of a solution containing the equivalent of 370 mg of iodine per mL. {76}



Ventriculography:
Via catheter, 25 to 50 mL of a solution containing the equivalent of 370 mg of iodine per mL. {76}



Venography, peripheral (phlebography):
Percutaneous, 25 to 150 mL of a solution containing the equivalent of 200 mg of iodine per mL per lower extremity. {76}



CT of the brain:
Intravenous, 100 to 150 mL of a solution containing the equivalent of 250 mg of iodine per mL; or 50 to 100 mL of a solution containing the equivalent of 300 mg of iodine per mL; or 41 to 81 mL of a solution containing the equivalent of 370 mg of iodine per mL. {76} {79}



CT of the body:
Intravenous, 130 mL of a solution containing the equivalent of 250 mg of iodine per mL; or 50 to 100 mL of a solution containing the equivalent of 300 mg of iodine per mL; or 81 mL of a solution containing the equivalent of 370 mg of iodine per mL, by rapid administration. {76} {79}



Urography, excretory:
Intravenous, 50 to 100 mL of a solution containing the equivalent of 250 mg of iodine per mL; or 50 mL of a solution containing the equivalent of 300 mg of iodine per mL, by rapid administration. {01} {05} {76}



Usual adult prescribing limits
Intrathecal
Up to 4.5 grams of iodine of a solution containing no more than the equivalent of 300 mg of iodine per mL. {77}

Intravascular {76}


Intra-arterial digital subtraction angiography:
Up to 350 mL (total of multiple doses).



Cerebral arteriography:
Up to 90 mL (total of multiple doses) of a solution containing the equivalent of 300 mg of iodine per mL.



Peripheral arteriography:
Up to 250 mL of a solution containing the equivalent of 300 mg of iodine per mL.



Selective visceral arteriography and aortography:
Up to 225 mL (total of multiple doses) of a solution containing the equivalent of 370 mg of iodine per mL.



Coronary arteriography and ventriculography:
Up to 200 mL of a solution containing the equivalent of 370 mg of iodine per mL.



Venography:
Up to 350 mL (total of multiple doses).



Usual pediatric dose
Intrathecal—Myelography
Lumbar1and

Thoracic myelography by lumbar injection of a solution containing the equivalent of 200 mg of iodine per mL—
Children 2 to 7 years of age: 7 to 9 mL.

Children 8 to 12 years of age: 8 to 11 mL.

Children 13 to 18 years of age: 10 to 12 mL. {77} {79}


Intravascular


Angiocardiography1:
By injection into a large peripheral vein or by direct catheterization of the heart as a solution containing the equivalent of 370 mg of iodine per mL {76}:

Children up to 2 years of age: 10 to 15 mL administered as a single dose.

Children 2 to 9 years of age: 15 to 30 mL administered as a single dose.

Children 10 to 18 years of age: 20 to 50 mL administered as a single dose.



CT of the brain:
Intravenous, 1 to 3 mL per kg of body weight of a solution containing the equivalent of 300 mg of iodine per mL. {79}



CT of the body:
Intravenous, 1.2 to 3.6 mL per kg of body weight of a solution containing the equivalent of 250 mg of iodine per mL; or 1 to 3 mL per kg of body weight of a solution containing the equivalent of 300 mg of iodine per mL. {76}



Urography, excretory:
Intravenous, 1.2 to 3.6 mL per kg of body weight of a solution containing the equivalent of 250 mg of iodine per mL; or 1 to 3 mL per kg of body weight of a solution containing the equivalent of 300 mg of iodine per mL. {76}



Usual geriatric dose
See Usual adult and adolescent dose .

Note: Geriatric patients with renal function impairment may be more sensitive to the effects of the usual adult dose; lower dosages are recommended.


Strength(s) usually available
U.S.—


261 mg of iopamidol with 128 mg of iodine per mL (Rx) [Isovue-128 (tromethamine 1 mg, edetate calcium disodium 0.17 mg, sodium 0.001 mEq)]


408 mg of iopamidol with 200 mg of iodine per mL (Rx) [Isovue-200 (tromethamine 1 mg, edetate calcium disodium 0.26 mg, sodium 0.001 mEq)] [Isovue-M 200 (tromethamine 1 mg, edetate calcium disodium 0.26 mg, sodium 0.001 mEq)]


510 mg of iopamidol with 250 mg of iodine per mL (Rx) [Isovue-250 (tromethamine 1 mg, edetate calcium disodium 0.33 mg, sodium 0.002 mEq)]


612 mg of iopamidol with 300 mg of iodine per mL (Rx) [Isovue-300 (tromethamine 1 mg, edetate calcium disodium 0.39 mg, sodium 0.002 mEq)] [Isovue-M 300 (tromethamine 1 mg, edetate calcium disodium 0.39 mg, sodium 0.002 mEq)]


755 mg of iopamidol with 370 mg of iodine per mL (Rx) [Isovue-370 (tromethamine 1 mg, edetate calcium disodium 0.48 mg, sodium 0.002 mEq)]

Canada—


261 mg of iopamidol with 128 mg of iodine per mL (Rx) [Isovue-128 (tromethamine 1 mg, edetate calcium disodium 0.17 mg, sodium 0.001 mEq)]


408 mg of iopamidol with 200 mg of iodine per mL (Rx) [Isovue-200 (sodium 0.001 mEq)]


612 mg of iopamidol with 300 mg of iodine per mL (Rx) [Isovue-300 (sodium 0.002 mEq)]


755 mg of iopamidol with 370 mg of iodine per mL (Rx) [Isovue-370 (sodium 0.003 mEq)]

Packaging and storage:
Store between 15 and 30 °C (59 and 86 °F), unless otherwise specified by manufacturer. Protect from light. Protect from freezing.

Stability:
Iopamidol is a clear, colorless to pale yellow solution. Do not use if turbid or discolored. {79}

Any unused portion remaining in the container should be discarded.

Crystals may form in the solution but are readily redissolved by immersing the container in hot water and gently shaking it. {79}

Incompatibilities:
Iopamidol is physically incompatible with other medications. Other medications must not be mixed in the same syringe or IV administration set. {77}



Revised: 07/21/1995



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