HEALTHNET

Do you know about Thyroid Disorders? (Part 2)

Hyperthyroidism occurs when there is excessive secretion of thyroid hormones...

(Posted on 12 October 2006)

Hyperthyroidism

Hyperthyroidism occurs when there is excessive secretion of thyroid hormones, which is also known as thyrotoxicosis, a common endocrine disease. Causes of thyrotoxicosis include over activity of the thyroid gland, presence of thyroid tumors and Graves' disease (an auto-immune disorder, in which the body produces antibodies and causes the enlargement of the thyroid gland).

Symptoms

Hyperthyroidism accelerates body's metabolic rate, which will affect body's physical functions. Typical symptoms include hyperidrosis, heat intolerance, nervousness, anxiety, palpitations, irascibility, insomnia, tiredness, diarrhea, increasing appetite with accompanying weight loss, exophthamox and thyroid gland enlargement.

Treatment

1. Drug Treatment
   To reduce the production of the thyroid hormone, commonly used drugs include Propylthiouracil and Carbimazole. Treatment is often started with a high dose, which will then step down gradually until symptoms subsided. Supplementary medications like beta blockers are indicated to reduce heart rate, relieve anxiety, alleviate hand tremors, nervousness and perspiration. Duration of treatment usually lasts for more than a year, with regular blood tests for dosage adjustment. Relapses are possible; therefore, regular thyroid function test is generally recommended. Common side effects include skin itchiness, skin rashes, joint pain, gastrointestinal disturbances and headache. Rare but serious side effects included thrombocytopenia and agranulocytosis.
2. Radioactive Iodine
   Radioactive iodine will destroy part of the thyroid gland, and reduce excessive secretion of thyroid hormone. Although it is convenient, effective and generally safe, over-damaging of the thyroid gland will lead to hypothyroidism, which then requires long-term intake of levothyroxine supplementation. Radioactive iodine is contraindicated in pregnancy.
3. Surgery
   With the widespread use of drug and radioactive iodine, thyroidectomy is less commonly used. It is now mainly indicated for patients with large thyroid tumor, those who do not wish to receive radioactive iodine or those who cannot tolerate drug treatment. Although surgery can produce a rapid relief, the procedures may injure the vocal chords and result in voice hoarseness.

There are pros and cons of different kinds of treatments, patients should seek medical advice from physicians and should not purchase over the counter medication.

Source: Hong Kong and Drug Education Resources Centre, The Society of Hospital Pharmacists of Hong Kong

More stories