Hyperthyroidism (Overactive Thyroid) - Treatment Options
In mild cases of hyperthyroidism, the thyroid may be monitored and the body may be able to heal itself without any antithyroid medication through rest and relaxation. However if the disease can no longer be controlled with rest then there are three treatment options;
Antithyroid drugs, such as Neo-Mercazole (carbimazole) and propylthiouracil (PTU), reduce thyroid hormone levels. Initially a high dose of antithyroid drugs is prescribed and as the thyroid hormone levels decrease, lower doses of antithyroid drugs are given. It usually takes a few weeks before the drugs start to work. Generally 30-50 % of patients achieve remission when they take one of these drugs for at least 6 months to one year. Some people may need antithyroid drugs for 18 months or even longer before they achieve remission.
Beta-blockers and tranquillisers may also be prescribed. However these drugs don’t treat the disease, but temporarily relieve symptoms associated with hyperthyroidism, such as palpitations, anxiety or a fast heartbeat.
Some potential problems that may occur as a result of the antithyroid medication are;
- Liver damage (uncommon, but if it happens then it usually occurs in the first three months). When liver function test becomes abnormal, stop the medication immediately.
- Aplastic anaemia - suppressed production of red blood cells in bone marrow (considered rare).
- Agranulocytosis (considered rare, but usually occurs in the first three months as well). Agranulocytosis is a severe decrease in the production of white blood cells and may put the patient at risk of serious infections. If you experience a sore throat and/or a fever, report this to your doctor immediately and have your white blood cell count measured.
- Vasculitis - inflammation of blood vessels.
Some other side effects you may experience are;
- Joint pain
- Itchy skin - hives
- Hair loss
- Stomach pain
- Vomiting and/or nausea
- Metallic taste
Doctors should order a thyroid function test, a liver function test and a full blood count at the same time on a regular basis to check for any possible adverse effects. Avoid excess iodine, which may interfere with antithyroid medication.
It is essential to monitor the thyroid hormone levels to avoid drug induced hypothyroidism (underactive thyroid). Researchers have demonstrated that drug induced hypothyroidism can cause cellular damage (tissue damage). If the thyroid hormone levels (free T4 and free T3) are low normal (lower end of the normal reference range) then the patient may experience symptoms of an underactive thyroid (despite a very low TSH) which can be treated with thyroxine (thyroid hormone). It is not uncommon for the TSH to remain low for a long period. A very low TSH and a positive test for thyroid stimulating antibodies after treatment with antithyroid medication can be a risk factor for a relapse of Graves’ disease in the future.
Patients with an overactive thyroid should be aware of the symptoms of hypothyroidism (see symptoms/signs of hypothyroidism and hyperthyroidism)!
Block & Replace Therapy for Hyperthyroidism
It is possible to take carbimazole or propylthiouracil in combination with thyroxine. Thyroid hormone levels are generally better controlled (more stable) on a combination therapy, but if the dose of carbimazole is too high then the side effects of the antithyroid medication may be undesirable. The carbimazole stops the production of thyroxine and the thyroxine medication replaces the thyroid hormone (which is why it is called ‘block and replace’). Some studies have reported a decrease in thyroid stimulating antibodies on a ‘block & replace’ therapy compared to patients who take antithyroid medication only. Some researchers have also reported that the rate of recurrence of hyperthyroidism is lower on a ‘block & replace’ therapy, but other studies have not confirmed this.
Patients are considered in remission when the TSH (thyroid stimulating hormone), free T4 and free T3 are within the normal range and the TSAb test (thyroid stimulating antibodies) has become negative. About three weeks after you stop the antithyroid medication, your levels are checked again. If the levels are still normal then the levels will be monitored every six months or so.
If antithyroid drugs have not been effective, then radioactive iodine is usually suggested by the doctor as a second treatment option. In some countries radioactive iodine treatment for hyperthyroidism is the treatment of choice and patients are not given other treatment options. Radioactive iodine is usually only used in adults and it can destroy a significant portion of the thyroid gland. About 30 % of patients need to be retreated with radioactive iodine one or more times.
However the majority of patients will become hypothyroid within weeks, months or years and will need to take thyroid hormone for life. This treatment cannot be used in pregnancy. If you suffer from thyroid eye disease then radioactive iodine treatment is not recommended.
The patient either has to drink a glass of water which contains radioactive iodine or take a capsule with radioactive iodine. The radioactive iodine goes through the blood stream and is absorbed by the thyroid gland where the iodine destroys the thyroid cells permanently. The majority of researchers claim that the use of radioactive iodine is safe and it does not appear to cause infertility or cancer elsewhere in the body. Other researchers claim that the risks of using radioactive iodine may outweigh the benefits for some people. For example some people may have an increased risk of damage to tissues close to the thyroid gland, such as salivary glands and tear ducts.
Surgical removal of the thyroid (thyroidectomy) is usually a last resort for people who have had no success with the other treatments or have experienced adverse reactions to medications. Surgery is generally also recommended for patients who have a large goitre, difficulty with breathing or swallowing and for patients suffering from thyroid eye disease. In some cases a part of the thyroid gland is left behind so it can still produce thyroid hormone.
Surgery on the thyroid gland should be done by an experienced surgeon who predominately performs surgery on the thyroid to avoid adverse outcomes. This is usually done by an endocrine surgeon. However patients are sometimes referred to a general surgeon, who may not have as much experience with surgery on the thyroid gland. Behind the thyroid gland are four small parathyroid glands and it is important that they will remain intact. If the parathyroid glands are damaged, calcium levels will drop. The thyroid gland is also located close to the nerves that control the voice box (called recurrent laryngeal nerves). The risk to impaired nerve function (voice impairment) is about 1%.
The patient may be treated with radioactive iodine and/or beta-blockers before the operation to avoid complications. You need to remember that if only part of the thyroid is taken out that in 30 % of patients the thyroid will become overactive again in the future. Obviously patients who have their thyroid removed need to take thyroid hormone for life.
Unfortunately all treatments for Graves’ disease are based on guesswork and getting it right or removing the right amount can be a real challenge unless you have a full thyroidectomy.
A potentially fatal complication of an overactive thyroid is called ‘thyroid storm’ (also known as thyrotoxic crisis). It can happen if you receive no treatment or inadequate treatment for an overactive thyroid, after surgery or it can be brought on by stress. Symptoms of ‘thyroid storm’ are as follows;
- Chest pain
- Mental deterioration
- High fever
- Heart failure
- Abdominal pain
- Extreme agitation
Copyright © 2011-2015 Monique Atkinson
Disclaimer The information provided is for educational purposes only and is not intended to be medical advice. The contents must not be relied upon in place of advice and treatment from a qualified medical practitioner. THYROID WA SUPPORT GROUP INC. and the author disclaim any liability whatsoever.