This disease and the ensuing hyperthyroidism do not go away on their own. Treatment is necessary for cure.
To achieve these goals, correcting the elevated levels of thyroid hormones is necessary. This is achieved either by antithyroid medications or radioactive iodine or surgery. Each option has its own criteria or indication.
We discuss here the indications, the advantage, and disadvantages of each of these management options.
Anti Thyroid drugs
Methimazole (MMI) and Propylthiouracil (PTU) are the drugs of choice. They are both administered orally and their clinical effects are seen within one hour after administration.
Both Methimazole and Propylthiouracil act by inhibiting the enzyme thyroid peroxidase and blocking the production of thyroid hormones. These antithyroid medications also have an immunosuppressive effect.
Methimazole can be given for 12 to 18 months and discontinued if the levels of the thyroid antibodies, TSH and TRAb, come to normal. If TRAb levels remain elevated the antithyroid medication can be continued for a longer period to increase chances of remission.
Longer-term treatment with medication may be needed in some cases.
It usually takes 6 to twelve weeks for the hyperthyroid symptoms to subside. While there is no standard set for how long you will have to take the medication, you will most likely be asked to continue with it for 12 to 18 months.
It can take as long as 6 months for your thyroid hormone levels to come to normal and stabilize with medication.
When you are on antithyroid drugs, your doctor will advise on periodical blood tests to make sure that your problem is under control and you are taking the right dose of medication.
However, if high hormone levels and hyperthyroidism symptoms persist after six months, other forms of therapy such as radioactive iodine or surgery will have to be considered.
One disadvantage of treating Graves’ disease with antithyroid medication is that it has a high rate of relapse (>50%).
Most physicians, therefore, choose radioactive iodine therapy as the first line of treatment for Graves’, especially in young patients.
Radioactive iodine therapy (RAI) or ablation
In patients who have developed Graves ophthalmopathy, radioactive iodine may worsen this condition; your doctor will be careful in such cases and may advise steroids to fight this complication.
Indications for radioactive iodine (sodium I-131) include a large thyroid gland, hyperthyroidism symptoms, high levels of thyroxine hormone, and high titers of TSI antibodies.
The radioactive iodine is given orally in a liquid form and in small doses. It gets concentrated in the thyroid where it destroys the overactive thyroid tissue and slows down the production of thyroxine.
Since the thyroid gland uses most of the iodine in the body, only a small amount of it is needed. The other tissues in the body stay unaffected by RAI.
The thyroid uses only what is required and rest of the iodine is excreted out of the body through urine, saliva, sweat, and stools.
Most patients treated with RAI wind up with hypothyroidism but it is the lesser of the two evils and it is easier to treat hypothyroidism than hyperthyroidism.
Thyroid function tests results usually improve within 6-8 weeks with RAI therapy. However, if they do not normalize within 6-12 months of treatment, a second similar or higher dose can be given.
The advantage of treating Greaves’ disease with RAI is that the relapse of Graves’ disease after RAI therapy is rare and you don’t have to face any risk of a surgery.
Radioactive iodine is contraindicated in pregnancy or if you are planning to become pregnant within the next one year. In such cases, surgery remains the best option.
Surgery of the thyroid gland is called thyroidectomy. It can be a partial resection of the thyroid gland in which case it is referred to as subtotal thyroidectomy. Total resection of the thyroid gland is called total thyroidectomy.
Surgery is not the first line of treatment for hyperthyroid Graves’ disease. However, it becomes indicated in the following cases when the patient
- cannot tolerate the anti-thyroid medication
- has moderate to severe ophthalmopathy
- refuses radioactive iodine
- has a large goiter
- develops severe Graves’ eye disease
- has a nodule suggestive of carcinoma
- is pregnant or even if the patient is planning to become pregnant in the next one year. This is because both antithyroid drugs and radioactive iodine are strictly contraindicated during pregnancy.
Subtotal thyroidectomy is indicated where a large portion of the thyroid can be safely left behind to avoid hypothyroidism and prevent the need for lifelong thyroid hormone medication.
However, the majority of surgeons recommend a total, or near-total, thyroidectomy for Graves’ disease since it becomes difficult to predict how much of the thyroid tissue to leave behind. In such cases where the whole thyroid gland is removed, lifelong synthetic thyroid hormones have to be taken.
Treatment after thyroidectomy
People who undergo total thyroidectomy and most people who undergo subtotal thyroidectomy need to take synthetic thyroid hormone replacement drugs (thyroxine) for the rest of their lives.
After starting this medication, the doctor periodically checks your blood hormone levels and sets the right dose for you.