Studies have not shown that sodium iodide I 131 increases the risk of cancer or other long-term problems. When using to treat an overactive thyroid gland, sodium iodide I 131 may cause the patient to have an underactive thyroid gland after treat. The thyroid gland may become underactive even few years after treat for hyperthyroidism. Before receiving this drug, be sure you have discussed its use with your family doctor.
Along with its needing effects, a drug may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
When this drug is using in very small doses to help study the function of the gland, side effects are rare. However, check with your family doctor as soon as possible if any of the following side effects occur after treat for overactive thyroid or cancer of the thyroid:
After treat of overactive thyroid
Symptoms of an underactive thyroid
Changes in menstrual periods; clumsiness; coldness; drowsiness; dry, puffy skin; headache; listlessness; muscle aches; thinning of hair - temporary may occur 2 to 3 months after treat; unusual tiredness or weakness; weight gain
Rare
After treat of overactive thyroid
Excessive sweating; fast heartbeat; fever; palpitations; unusual irritability; unusual tiredness
After treat of cancer of the thyroid
Black, tarry stools; blood in urine or stools; cough or hoarseness; fever or chills; lower back or side pain; painful or difficult urination; pinpoint red spots on skin; unusual bleeding or bruising
More common side effects may occur that usually don't needed medical attention. These side effects may go away during treat as your body adjusts to the drug. However, check with your family doctor if any of the following side effects continue or are bothersome:
Less common
After treat of overactive thyroid or cancer of the thyroid
Neck tenderness or swelling; sore throat
After treat of cancer of the thyroid
Loss of taste - temporary; nausea and vomiting - temporary; tenderness of salivary glands
Other side effects not listed above may also occur in some diseaseds. If you notice any other problems, check with your family doctor.