Patient 4 is an Indonesian Malay lady aged 45 years old. She has been prescribed the following drugs from the Endocrine Department:
1. CARBIMAZOLE 5MG TABLET
Take ONE tablet every other day
General Overview
Patient 4 is probably having hyperthyroidism. The thyroid gland is a butterfly-shaped endocrine gland that is located in the lower front of the neck. Thyroid gland produces thyroid hormones, which are secreted into the blood and carried to body tissues. Thyroid hormone helps the body to use energy, stay warm and keep organs such as the brain, heart and muscles working normally. Hyperthyroidism (as suffered by Patient 4), refers to any condition whereby there is too much thyroid hormone being produced by the overactive thyroid gland in the body.
The most common cause of hyperthyroidism is the overproduction of thyroid hormone by the entire thyroid gland. This condition is also known as Graves; disease. Graves’ disease is an autoimmune disease caused by antibodies in the blood that turn on the thyroid and cause it to grow and secret too much thyroid hormone. This type of hyperthyroidism tends to run in the family and occurs more in young women.
Another type of hyperthyroidism is characterized by one or more nodules or lumps in the thyroid that may gradually grow and increase their activity so that the total output of thyroid hormone into the blood is greater than normal. This condition is known as toxic nodular or multinodular goiter.
Hyperthyroidism may also be caused by a condition called thyroiditis. It can be due to a problem with the immune system or a viral infection that causes the thyroid gland to leak stored thyroid hormone.
Not forgetting, hyperthyroidism can be caused by taking too much thyroid hormone in tablet form. In cases where the thyroid is not overactive (latter two cases), the condition is referred to as thyrotoxicosis.
Clinical presentations for hyperthyroidism are often related to the role of thyroid hormones, which affects the body’s metabolism. With too much thyroid hormones, every function of the body tends to speed up. Hence, common symptoms of hyperthyroidism includes nervousness, irritability, increased perspiration, increased heart rate, hand tremors, anxiety, difficulty sleeping, thinning of skin, fine brittle hair and muscle weakness especially in the upper arms and thighs.. Although frequent bowel movements may also occur, diarrhea is fairly uncommon. Patients with hyperthyroidism may also lose weight despite a good appetite and women may experience light menstrual flow and less often menstrual periods. It is also important to note that individuals with hyperthyroidism may have a lot of energy initially as their metabolism is increased. However, they can be very tired in the long run due to the breaking down of their body. Hyperthyroidism usually begins slowly (but can be quite abrupt in some young patients) and initial symptoms may be mistaken for simple nervousness due to stress. Graves’ disease is the most common form of hyperthyroidism. Individuals with Graves’ disease have a very distinct clinical presentation, in which their eyes may look enlarged because the upper lids are elevated. some patients may also have swelling of the front of the neck due to an enlarged thyroid gland (a goiter).
Besides these clinical presentations, hyperthyroidism can be confirmed by laboratory tests that measure thyroid hormones – thyroxine (T4) and triiodothyronine (T3) – and thyroid-stimulating hormone (TSH) in blood. (Usually TSH and T4 are checked. T3 is 4-fold more potent than T4 because T3 is the active form of thyroid hormone. This is important when changing doses. For example, prescreption t3 at a dose of 25mcg is equals to T4 at a dose of 100mcg) Overactive thyroid glands usually records a high level of thyroid hormone in the blood plus a low level of TSH.
General Treatment:
1. Antithyroid Drugs
Antithyroid drugs may be prescribed to to treat hyperthyroidism by blocking the thyroid gland’s ability to make new thyroid hormone. These include Methimazole (Carbimazole is the pro-drug of methimazole) or in rare instances propylthiouracil (PTU). Methimazole is more of the preferred choice due to less severe side effects. Drugs in this class work well to control the overactive thyroid, bring quick control of hyperthyroidism and do not cause permanent damage to the thyroid gland. However, antithyroid drugs may cause allergic reactions (about 5% of patients) resulting in red skin rashes, hives, fever and joint pains. A rare but serious side effect of antithyroid drugs is a decrease in the number of white blood cells, resulting in a lowering of resistance to infection. Hence, it is always important to advice patients on antithyroid drugs to alert their doctor immediately when they experience fever or sore throat, which may indicate the presence of infection. Liver damage is another very rare side effect. Hence, always advice patients to alert the doctor immediately if they notice any yellowing of eyes or skin, dark urine, severe fatigue or abdominal pain.
2. Radioactive Iodine
This treatment method involves damaging or destroying the thyroid cells that make thyroid hormone. As these cells need iodine to make thyroid hormone, they will take up any form of iodine in the bloodstream, regardless if it is radioactive or not. The radioactive iodine used in this treatment is administered by mouth (capsule) and is taken just once. Radioactive iodine gets into the bloodstream and is quickly taken up by overactive thyroid cells. Radioactive iodine that is not taken up by thyroid cells will disappear from the body within days. During this period of several weeks to several months, radioactive iodine destroys the cells that have taken it up. As a result, the thyroid shrink in size and the level of thyroid hormone in the blood returns to normal. A second radioactive iodine treatment can be given if patient is still hyperthyroid after the first treatment. If patient becomes hypothyroid, it can be easily managed with a thyroid hormone supplement taken once a day.
3. Surgery
Hyperthyroidism can be PERMANENTLY cured by surgical removal of most of the thyroid gland. As a pre-operation preparation, the hyperthyroidism must first be controlled by an antithyroid drug or a beta-blocking drug. For some days before surgery, some patients may be given drops of NONradioactive iodine, which will help to reduce the blood supply to the thyroid gland, hence making the surgery easier and safer. It is very likely that individuals who opt for thyroid removal surgery will develop hypothyroidism, which again, can be managed by thyroid hormone supplement.
4. Beta-Blockers
Beta-blockers may be an additional drug on top of any of the 3 methods above. It acts by blocking the action of thyroid hormone in the body. Beta-blockers usually has a fast onset, making a hyperthyroid patient feel better within hours. However, Beta-blockers do NOT change the high levels of thyroid hormone in the blood. It is exceptionally useful in slowing down the heart rate and reducing symptoms of palpitations, shakes and nervousness until other forms of treatment as a chance to take effect.
Lastly, hyperthyroidism, especially Graves’ disease may run in families. Hence, examinations of family members may reveal other individuals with thyroid problems.
Patient-Specific Treatment:
1. CARBIMAZOLE 5MG TABLET
Information: Carbimazole is a pro-drug of methimazole. It is converted to its active form after absorption. Methimazole prevents the thyroid peroxidase enzyme from coupling and iodinating the tyrosine residues of thyroglobulin, hence reducing the production of thyroid hormones T3 and T4.
Counseling: Carbimazole is a medication that helps to reduce the levels of thyroid hormones in your body. This means that it will help to reduce symptoms caused by high thyroid hormone levels such as agitation, tremors, fast heartbeats, difficulty sleeping and muscle weakness. Take 1 tablet of Carbimazole 5mg every other day at approximately the same time every time. When taking this medication, you may experience so common and mild side effect such as itching, hair loss and stomach discomfort. If any of these side effects are severe, please alert your doctor. However, it is important for you to take note of some of the signs of rare but serious side effects. Firstly, if you have a fever or sorethroat that does not go away while taking this medication, alert your doctor immediately. It may be a sign of infection due to your lowered immunity. Secondly, if you notice darkening of your urine to a tea colored color, yellow eyes and skin, several fatigue or unexplained abdominal pain, please alert your doctor immediately. It may be a sign of liver damage. Thirdly, if you have any sudden changes in weight (increased or decreased) or sudden increased sensitivity to temperature or even sudden change in appetite without explanation (for example not after exercise and not after missing meals), please alert your doctor. It may be a sign that the medication is either not suitable for you or it is not given at an optimum dose. If this is your first time taking this medication, please look out for signs of hypersensitivity or allergy such as rashes around the face and the eyes, swelling on your face or difficulty breathing. If any of these signs occur, stop the medication immediately and alert your doctor. If severe, please visit the A&E department immediately. Hyperthyroidism may also run in the family. Hence, we would recommend you to have your family members to go for regular medical check ups to check for hyperthyroidism in order to detect any possible thyroid related conditions as early as possible to allow optimum and effective management.
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