Neo-Mercazole 5 (Carbimazole)

Neo-Mercazole general information

What is Neo-Mercazole used for?

Neo-Mercazole tablets 5mg are used to treat hyperthyroidism or over-active thyroid, which causes thyrotoxicosis due to over production of thyroid hormone.  The most common form of hyperthyroidism is Grave’s Disease or goitre, which is thought to be an autoimmune disease where autoantibodies called thyroid stimulating immunoglobulins bind to the receptor for Thyroid Stimulating Hormone (TSH) and cause loss of regulation of thyroid hormone production.  Hyperthyroidism can also be caused by inflammation, a tumour or a virus infection.  Symptoms of hyperthyroidism are due to increased production of thyroid hormone, which causes increased rate of metabolism.  They include nervousness, restlessness, irritability difficulty concentrating, tiredness, rapid heartbeat, heat intolerance, increased perspiration, difficulty sleeping, hand tremors, weight loss, increased appetite, frequent bowel movements, and muscular weakness.  Neo-Mercazole tablets 5mg are used to help induce permanent remission from thyrotoxicosis; also to restore normal thyroid function before thyroid surgery to remove whole or part of the thyroid gland; also before and after treatment with radioactive iodine for overactive thyroid.  Neo-Mercazole tablets 5mg is not used for a simple non-toxic goitre in which the thyroid may not make enough thyroid hormone but otherwise functions normally.  

How does Neo-Mercazole work?

Neo-Mercazole tablets 5mg contain carbimazole, which is a pro-drug and is rapidly metabolised after absorption into its active form methimazole.  This metabolite inhibits the action of thyroid peroxidase, an enzyme that is involved in the coupling and iodination of thyroglobulin, which is important for the synthesis of thyroid hormone.  Hyperthyroidism is due to an overactive thyroid gland and overproduction of thyroid hormone, which exists in two forms, thyroxine or levothyroxine, also known as T₄ and liothyronine or L-triiodothyronine also known as T₃.  The production of thyroid hormone is normally regulated by thyroid stimulating hormone (TSH), a hormone produced by the pituitary gland in the hypothalamus, at the base of the brain, and it is this regulation that is deficient in Grave’s disease.  Carbimazole in Neo-Mercazole tablets 5mg blocks the synthesis of thyroid hormone and thereby helps restore normal levels.

What does Neo-Mercazole contain?

Neo-Mercazole tablets 5mg contain the active ingredient carbimazole, an anti-thyroid drug used to treat hyperthyroidism.  They also contain: lactose, maize starch, sucrose, magnesium stearate, talc, gum acacia, ferric oxide, gelatin.

Treating hyperthyroidism with Neo-Mercazole

Neo-Mercazole tablets 5mg contain carbimazole and are used to treat hyperthyroidism.  Overproduction of thyroid hormone causes hyperthyroidism, also known as over-active thyroid and results in increased rate of metabolism.  Hyperthyroidism exists in different forms, the most common of which is Grave’s Disease or goitre that is thought to be an autoimmune disease where autoantibodies called thyroid stimulating immunoglobulins bind to the receptor for Thyroid Stimulating Hormone (TSH).  Hyperthyroidism can also be caused by inflammation, a tumour or a virus infection.  Thyroid hormone exists in two forms, thyroxine or levothyroxine, also known as T₄ and liothyronine or L-triiodothyronine also known as T₃.  The production of thyroid hormone is normally regulated by TSH, a hormone produced by the pituitary gland in the hypothalamus, at the base of the brain, and it is this regulation that is deficient in hyperthyroidism.  Carbimazole in Neo-Mercazole tablets 5mg inhibits the action of thyroid peroxidase, which is important in the synthesis of thyroid hormone.  This action helps restore normal levels of thyroid hormone and relieves symptoms of hyperthyroidism, which include nervousness, restlessness, irritability difficulty concentrating, tiredness, rapid heartbeat, heat intolerance, increased perspiration and difficulty sleeping, hand tremors, weight loss, increased appetite, frequent bowel movements, and muscular weakness.

Neo-Mercazole for Grave’s Disease

Neo-Mercazole tablets 5mg contain carbimazole, an anti-thyroid drug that is used to treat Grave’s Disease, which is the most common form of hyperthyroidism.   Grave’s Disease is thought to be an autoimmune disease where autoantibodies called thyroid stimulating immunoglobulins bind to the receptor for Thyroid Stimulating Hormone (TSH).  The production of thyroid hormone is normally regulated by TSH, a hormone produced by the pituitary gland in the hypothalamus, at the base of the brain, and it is this regulation that is deficient in hyperthyroidism resulting in over-active thyroid, overproduction of thyroid hormone and increased rate of metabolism.  Grave’s Disease is characterised by goitre or swelling of the thyroid gland and thyrotoxicosis (high levels of thyroid hormones), resulting in symptoms including nervousness, restlessness, irritability difficulty concentrating, tiredness, rapid heartbeat, heat intolerance, increased perspiration and difficulty sleeping, hand tremors, weight loss, increased appetite, frequent bowel movements, and muscular weakness.  Carbimazole in Neo-Mercazole tablets 5mg inhibits the action of thyroid peroxidase, an important enzyme in the synthesis of thyroid hormone.  This action blocks the production of thyroid hormone and helps restore normal levels of thyroid hormone to relieve symptoms of Grave’s Disease.

What are the side effects of Neo-Mercazole?

The most commonly reported side effects when taking Neo-Mercazole tablets 5mg include gastrointestinal upset, nausea, headache, dizziness, paraesthesia (sensation of tingling, numbness), arthralgia (painful joints), skin rash, itching (pruritus), loss of taste.  Agranulocytosis (reduced white cell count) is a possible serious side effect that should be monitored for symptoms like sore throat, bruising, bleeding, mouth ulcers, fever and malaise

When should Neo-Mercazole not be used?

You should not use Neo-Mercazole tablets 5mg if you:

• are allergic to carbimazole or any ingredients in Neo-Mercazole
• are pregnant or are breastfeeding, without discussion with your doctor
• have liver disease
• have a serious haematological condition 
• have a simple non-toxic goitre (swelling on the neck caused by enlargement of the thyroid gland)
• are taking medicines that interact with Neo-Mercazole, including: vitamin K-dependant anticoagulants, agranulocytosis inducing drugs, theophylline for asthma

What medications interact with Neo-Mercazole?

Several medications interact with Neo-Mercazole tablets 5mg and should either not be taken while you are taking Neo-Mercazole or only after discussion and instruction from your doctor:

• Drugs that cause a serious reaction with Neo-Mercazole: agranulocytosis inducing drugs
• Drugs that affect Neo-Mercazole: vitamin K-dependant anticoagulants, theophylline for asthma

How should Neo-Mercazole be taken?

You should take your Neo-Mercazole tablets 5mg swallowed whole with a glass of water with or without food.  The dose you take and how often will depend on the severity of your condition and your doctor’s recommendation and may be once, twice or three times a day.  Your dose may be reduced depending on how well you respond.  You should see an improvement within three months but you should continue to take your Neo-Mercazole tablets 5mg for several months or years depending on your condition and your doctor’s recommendation.

How long should you take Neo-Mercazole?

You should continue to take your Neo-Mercazole tablets 5mg for several months or years depending on your condition and your doctor’s recommendation.

Missed dose of Neo-Mercazole

If you miss a dose of Neo-Mercazole tablets 5mg take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose.  Do not take a double dose.

How should Neo-Mercazole be stored?

You should store your Neo-Mercazole tablets 5mg below 25°C in a cool dry place.