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Iodine and potassium iodide (strong iodine) (Oral)

Generic name: iodine and potassium iodide (strong iodine) [ EYE-oh-dine, poe-TAS-ee-um-EYE-oh-dide ]
Drug class: Minerals and electrolytes

Medically reviewed by Last updated on Jun 29, 2022.

Uses for iodine and potassium iodide (strong iodine)

Strong iodine is used to treat overactive thyroid, iodine deficiency, and to protect the thyroid gland from the effects of radiation from radioactive forms of iodine. It may be used before and after administration of a radioactive medicine containing radioactive iodine or after accidental exposure to radiation (for example, from nuclear power plant accidents). It may also be used for other conditions as determined by your doctor.

Strong iodine is available only with your doctor's prescription.

Before using iodine and potassium iodide (strong iodine)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Strong iodine may cause skin rash and thyroid problems in infants.


Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of strong iodine in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Breast Feeding


Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.

Potassium IodidePotassium Iodide

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Acenocoumarol
  • Anisindione
  • Dicumarol
  • Phenindione
  • Phenprocoumon
  • Warfarin

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Bronchitis or
  • Other lung conditions—Use of strong iodine may make this condition worse
  • Hyperkalemia (too much potassium in the blood) or
  • Kidney disease—Use of strong iodine may increase the amount of potassium in the blood and increase the chance of side effects

Proper use of iodine and potassium iodide (strong iodine)

For patients taking this medicine for radiation exposure:

  • Take this medicine only when directed to do so by state or local public health authorities.
  • Take this medicine once a day for 10 days, unless otherwise directed by public health authorities. Do not take more of it and do not take it more often than directed. Taking more of the medicine will not protect you better and may result in a greater chance of side effects.

If strong iodine upsets your stomach, take it after meals or with food or milk unless otherwise directed by your doctor. If stomach upset (nausea, vomiting, stomach pain, or diarrhea) continues, check with your doctor.

This medicine is to be taken by mouth even if it comes in a dropper bottle.

Do not use this solution if it turns brownish yellow.

Take strong iodine in a full glass (8 ounces) of water or in fruit juice, milk, or broth to improve the taste and lessen stomach upset. Be sure to drink all of the liquid to get the full dose of medicine.

If crystals form in strong iodine solution, they may be dissolved by warming the closed container of solution in warm water and then gently shaking the container.


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (solution):
    • To treat overactive thyroid (hyperthyroid):
      • Adults and teenagers—One milliliter (mL) three times a day. The first dose is taken at least one hour after the first dose of your antithyroid medicine.
      • Children—Use and dose must be determined by your doctor.
    • To prepare for surgery to remove thyroid gland:
      • Adults, teenagers, and children—3 to 5 drops (approximately 0.1 to 0.3 mL) three times a day for ten days before surgery. This medicine is usually given along with your antithyroid medicine.
    • To protect the thyroid gland against radiation exposure:
      • Adults and teenagers—130 mg once a day for ten days.
      • Children—65 mg once a day for ten days.
    • To treat iodine deficiency:
      • Adults and teenagers—0.3 to 1 mL three to four times a day.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Precautions while using iodine and potassium iodide (strong iodine)

Your doctor should check your progress at regular visits to make sure that this medicine does not cause unwanted effects.

For patients on a low-potassium diet:

  • This medicine contains potassium. Check with your health care professional before you take this medicine.

Side Effects of iodine and potassium iodide (strong iodine)

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

Less common

  • Hives
  • joint pain
  • swelling of the arms, face, legs, lips, tongue, and/or throat
  • swelling of the lymph glands

With long-term use

  • Burning of mouth or throat
  • confusion
  • headache (severe)
  • increased watering of mouth
  • irregular heartbeat
  • metallic taste
  • numbness, tingling, pain, or weakness in hands or feet
  • soreness of teeth and gums
  • stomach upset
  • symptoms of head cold
  • unusual tiredness
  • weakness or heaviness of legs

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

  • Diarrhea
  • nausea or vomiting
  • stomach pain

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

More about iodine / potassium iodide

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.