Iopanoic acid

By Medically reviewed by hellodoktor

Generic Name: Iopanoic acid Brand Name(s): Iopanoic acid and Iopanoic acid.


What is iopanoic acid used for?

Iopanoic acid is commonly used for radiographic delineation of the gallbladder. It is used for treatment hyperthyroidism, in Graves’ disease.

How should I take iopanoic acid?

This drug is taken by mouth. Swallow it whole. Do not take this medicine in larger amounts or for longer than recommended.

How do I store iopanoic acid?

Iopanoic acid is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store iopanoic acid in the bathroom or the freezer. There may be different brands of iopanoic acid that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush iopanoic acid down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using iopanoic acid?

Before using this drug, there are some important information that you may notice:

  • Pretreatment with corticosteroids and/or antihistamines is recommended to 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).
  • As a preparatory measure for cholecystography, patient is recommended to ingest a fatty meal on the day prior to the initial oral dose of the cholecystographic agent, regardless of the nature of the agent. This will induce gallbladder contractions and elimination of the contents of the gallbladder. Whether or not the evening meal immediately prior to the administration of the cholecystographic agent should contain fat is dependent on the nature of the contrast medium used. When using iopanoic acid as the contrast agent, it has been shown that a reasonable amount of dietary fat enhances gastrointestinal absorption of the agent, and thus, better opacification of the gallbladder is obtained. Conversely, ingestion of a fatty meal with other cholecystographic agents decreases their absorption.
  • The fatty meal is being replaced, in some cases, by a commercially available oral fat emulsion, which is usually administered 20 minutes before diagnostic imaging of the gallbladder.
  • During the interval between ingestion of the cholecystographic agent and the time of the examination, the patient should not take anything by mouth except water. Also, smoking or chewing gum is not recommended since the resulting increase in gastric acidity may affect intestinal motility and absorption of the agent.

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using iopanoic acid during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking iopanoic acid. Iopanoic acid is pregnancy risk category C, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side effects

What side effects can occur from iopanoic acid?

Acute renal insufficiency has been reported following oral administration of cholecystographic agents, especially when these agents were used in large doses or with other agents, or in dehydrated patients or those with hepatic disease.

These side effects need for medical attention only if they continue or are bothersome:

  • Mild diarrhea
  • Mild to moderate nausea and vomiting
  • Abdominal or stomach spasms or cramps
  • Severe diarrhea
  • Difficult or painful urination
  • Dizziness
  • Frequent urge to urinate
  • Headache
  • Heartburn
  • Severe or continuing nausea and vomiting

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with iopanoic acid?

Iopanoic acid may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Does food or alcohol interact with iopanoic acid?

Iopanoic acid may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with iopanoic acid?

Iopanoic acid may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using iopanoic acid.

What is the dose of iopanoic acid for an adult?


The recommended dose is 3 grams, orally.

Anti-hyperthyroidism (Graves’ disease)

The recommended dose is 500 mg to 1 gram once a day, orally.

Usual adult prescribing limits

Up to 6 grams in a twenty-four-hour period.

What is the dose of iopanoic acid for a child?


Children weighing up to 13 kg: The recommended dose is 150 mg per kg of body weight, orally.

Children weighing 13 to 23 kg: The recommended dose is 2 grams, orally.

Children weighing 23 kg or more: The recommended dose is 3 grams, orally.

How is iopanoic acid available?

Iopanoic acid is available in the following dosage forms and strengths:

  • Tablet; Oral; iopanoic acid 500 mg

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of iopanoic acid, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: March 11, 2017 | Last Modified: September 12, 2019

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