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Lugol's Side Effects

Generic Name: iodine / potassium iodide

Note: This page contains information about the side effects of iodine / potassium iodide. Some of the dosage forms included on this document may not apply to the brand name Lugol's.

Applies to iodine / potassium iodide: oral solution

In addition to its needed effects, some unwanted effects may be caused by iodine / potassium iodide. In the event that any of these side effects do occur, they may require medical attention.

Severity: Moderate

If any of the following side effects occur while taking iodine / potassium iodide, check with your doctor or nurse as soon as possible:

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

Minor Side Effects

Some of the side effects that can occur with iodine / potassium iodide may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

Less common:
  • Diarrhea
  • nausea or vomiting
  • stomach pain

Not all side effects for Lugol's may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

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