Treatment Options for Hyperthyroidism (Overactive Thyroid)
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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

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 heart beat.

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;

  • Headaches
  • Joint pain
  • Itchy skin - hives
  • Hair loss
  • Stomach pain
  • Vomiting and/or nausea
  • Fever
  • 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.


Radioactive Iodine

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.


Surgery

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.


Thyroid Storm

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
  • Vomiting
  • Diarrhoea
  • Abdominal pain
  • Jaundice
  • Extreme agitation
  • Coma


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.
Copyright © Monique Atkinson 2011

Thyroid WA Support Group Inc.  -  ABN  84 263 220 330