Name: ThyroShield

ThyroShield Overview

ThyroShield is a brand name medication included in the following groups of medications: Antidotes, Expectorants, OTHER OPHTHALMOLOGICALS. For more information about ThyroShield see its generic Potassium Iodide

What is ThyroShield (potassium iodide)?

Potassium iodide is the potassium salt form of iodide, a naturally occurring substance.

Potassium iodide can be used as an expectorant to thin mucus and loosen congestion in your chest and throat.

Potassium iodide is used in people with chronic breathing problems that can be complicated by thick mucus in the respiratory tract, such as asthma, chronic bronchitis, or emphysema.

Potassium iodide may also be used for purposes not listed in this medication guide.

What other drugs will affect ThyroShield (potassium iodide)?

Tell your doctor about all medicines you use, and those you start or stop using during your treatment with potassium iodide, especially:

  • lithium;

  • an ACE inhibitor--benazepril, captopril, enalapril, fosinopril, lisinopril, moexipril, perindopril, quinapril, ramipril, or trandolapril;

  • a diuretic or "water pill"--amiloride, spironolactone triamterene;

  • medications to treat overactive thyroid--methimazole, propylthiouracil (PTU), radioactive iodine; or

  • multivitamin or mineral supplements that contain potassium.

This list is not complete. Other drugs may interact with potassium iodide, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Uses For ThyroShield

Potassium iodide is used to treat overactive thyroid and to protect the thyroid gland from the effects of radiation from inhaled or swallowed radioactive iodine. It may be used before and after administration of medicine containing radioactive iodine or after accidental exposure to radioactive iodine (for example, from nuclear power plant accidents that involved release of radioactivity to the environment). It may also be used for other problems as determined by your doctor.

Potassium iodide is taken by mouth. It may be taken as an oral solution, syrup, uncoated tablet, or enteric-coated delayed-release tablet. However, the delayed-release tablet form may cause serious side effects and its use is generally not recommended.

Some brands of the oral solution are available without a prescription.

What do I need to tell my doctor BEFORE I take ThyroShield?

  • If you have an allergy to potassium iodide, iodine, or any other part of ThyroShield (potassium iodide solution).
  • If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
  • If you have any of these health problems: Certain skin or blood vessel problems.
  • If you have a growth on your thyroid gland and you have heart disease.

This is not a list of all drugs or health problems that interact with this medicine.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take ThyroShield with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take ThyroShield?

  • Tell all of your health care providers that you take this medicine. This includes your doctors, nurses, pharmacists, and dentists.
  • Have blood work checked as you have been told by the doctor. Talk with the doctor.
  • Talk with your doctor before using a salt substitute.
  • Take ThyroShield only as you have been told. Do not take more than you were told to use or more often then you were told to take it. Taking too much of this medicine may raise the risk of side effects. Do not take ThyroShield if you are allergic to iodine.
  • This medicine may cause harm to the unborn baby if you take it while you are pregnant.
  • Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using this medicine while you are pregnant.
  • Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.
  • Have your baby's thyroid checked if you are using ThyroShield and breast-feeding.

What are some other side effects of ThyroShield?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Headache.
  • Upset stomach or throwing up.
  • Belly pain.
  • Loose stools (diarrhea).

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at

Questions or Comments?

call toll free 1-800-343-0164


Each milliliter (1 mL) of Thyroshield® contains 65 mg of potassium iodide (USP) in a black raspberry-flavored solution. Inactive ingredients are: FD&C Red #40 and Blue #1, methylparaben, natural and artificial black raspberry flavor, propylene glycol, propylparaben, purified water (USP), sodium saccharin, sucrose.

For Healthcare Professionals

Applies to potassium iodide: compounding powder, oral liquid, oral solution, oral tablet


Endocrinologic side effects have included both hyper- and hypothyroidism. By inhibiting the release of thyroid hormone from the thyroid gland, iodide can cause goiter and hypothyroidism. This has been called the Wolff-Chaikoff effect, occurring in approximately 4% of patients, and may be more likely in patients with cystic fibrosis (CF). Iodide may induce hyperthyroidism, called the Jod-Basedow effect, when given to patients with preexisting iodide deficiency or autonomous, "hot" thyroid nodules. Iodide can cause parotid gland swelling.[Ref]

In one study of 55 patients with CF who were treated with iodides, 47 developed goiters, and 14 had clinical or laboratory evidence of hypothyroidism. In 2 of the 14 hypothyroidism occurred in the absence of a goiter. Subsequent data are consistent with the possibility that peripheral deiodination of T4 to T3 may be impaired in these patients. Failure to appreciate this can lead to the erroneous diagnosis of congenital hypothyroidism in some patients with CF.[Ref]


The pathogenesis of vegetating iododerma is not clear, may be idiosyncratic, and appears to involve a hyperinflammatory response. Iodides appear to increase the movement of polymorphonuclear leukocytes (PMNLs) into areas of inflammation, enhancing the inflammatory response. Since PMNLs are known to increase connective tissue proliferation, iodides could convert an area of inflammation into an area of proliferative tissue, providing and explanation for proliferative iododermas.[Ref]

Dermatologic side effects have included iododerma in approximately 1% of patients. Iododerma is a term used describe a wide range of dermatologic side effects of KI that typically affect the face, neck, back and upper extremities. Iododerma may present as acneiform vesiculobullous, vesicular, pustular, hemorrhagic or urticarial lesions. The incidence of skin eruptions associated with the use of KI in inpatients from the Boston Collaborative Surveillance Program was less than 0.6%. Rare cases of urticaria, angioedema, polymyalgia, and life-threatening systemic reactions have been associated with the use KI in patients with underlying connective tissue disorders.[Ref]


Rare cases of severe, ulcerative, vegetating iododerma in patients with underlying polyarteritis nodosa, arthritis, lymphoma, subacute glomerulonephritis, multiple myeloma, dermal vasculitis or hypocomplementemia have been reported.[Ref]

Hypersensitivity side effects have included rash, fever, eosinophilia, jaundice, pruritus, angioedema, lymphadenopathy, arthralgia, bronchospasm, submucosal hemorrhage and periarteritis nodosa-type reactions. Bullous iododerma appear to be an allergic reaction, and can be fatal. Other known hypersensitivity reactions to iodides include hematuria, proteinuria, and pulmonary edema. Predisposing risk factors for hypersensitivity reactions appear to include some underlying connective tissue disorders.[Ref]


Gastrointestinal side effects have included "upset stomach" in 10% to 40% of patients, depending on the dose. Other common GI complaints include an unpleasant, "brassy" taste, throat or retrosternal burning, sore gums, and salivation. In rare cases and in cases of overdose, esophagitis and gastritis have been reported.[Ref]


Iodide may interfere with certain autoanalyzer measurements of serum chloride, resulting in falsely elevated values. The "true" anion gap in some cases can, therefore, be higher than the calculated anion gap. "Hyperchloremic acidosis" has been associated with ingestion of KI. In some cases of KI overdose, the anion gap was due to the presence of high serum levels of lactic acid.[Ref]

Metabolic side effects have included metabolic acidosis following KI overdose.[Ref]


Renal side effects have included acute renal failure secondary to tubular necrosis following KI overdose.[Ref]


Hematologic side effects have included rare reports of hemolytic anemia, and appear to be limited to cases of overdose.[Ref]


Immunologic side effects have included rare cases of systemic granulomatous vasculitis.[Ref]

A 37-year-old female with Sweet's syndrome was successfully treated with potassium iodide. Within 12 days after beginning therapy, however, she developed malaise, diminished vision, hypertension, rash, and fever. Physical and laboratory findings revealed new renal insufficiency, bilateral papillitis on retinal examination, and leukocytoclastic vasculitis per skin biopsy. Renal biopsy and renal and mesenteric angiography were normal. The patient's signs and symptoms resolved over 11 months with the addition of oral prednisolone therapy.[Ref]

Some side effects of ThyroShield may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.