Thyroid Generic Drugs F.A.Q.
What thyroid gland is responsible for?
Thyroid gland is an endocrine gland that stores iodine and produces iodine-containing hormones which regulate the metabolism, play role in growth of separate cells and the body at whole. These hormones are tetraiodothyronine, (T4) and triiodothyronine (T3). The synthesis of these hormones occurs in epithelial follicular cells called thyrocytes. Calcitonin, a peptide hormone, is also synthesized in the thyroid gland in parafollicular or C-cells. It compensates for bone deterioration by embedding calcium and phosphate in bone tissue, and also prevents the formation of osteoclasts, which in the activated state can lead to the destruction of bone tissue, and stimulates the functional activity and reproduction of osteoblasts. Thus it regulates the action of these two types of formations and promotes bone tissue development.
The gland is situated on the neck under the larynx before the trachea. In humans, it has the shape of a butterfly and is located on the surface of the thyroid cartilage.
Diseases of the thyroid gland can be accompanied by the unchanged, lowered, or increased endocrine function (production of hormones).
In some territories, the deficit of iodine can cause the development of endemic goiter and even cretinism.
What are the diseases of the thyroid gland?
– Hypothyroidism. It is a condition induced by the long-term and persistent lack of thyroid hormones, the opposite of thyrotoxicosis. The extreme manifestation of the clinical symptoms of hypothyroidism in adults is myxedema (as a result of the dysfunction of protein metabolism, organs and tissues become swollen), cretinism (delayed physical and mental development) in children.
– Hyperthyroidism (Thyrotoxicosis). It is a syndrome caused by hyperfunction of the thyroid gland manifested by an increase in the content of hormones: triiodothyronine (T3), thyroxin (T4). Depending on the level of occurrence of the disorder, the following types of hyperthyroidism are distinguished: primary - thyroid, secondary - pituitary, tertiary - hypothalamus.
– Autoimmune thyroiditis. It is a chronic inflammatory disease of the thyroid gland of autoimmune genesis. The pathogenetic mechanisms of autoimmune thyroiditis are not fully understood. The cause of the disease is a partial genetic defect in the immune system; as a result, specific morphological changes of varying severity (from lymphoplasmacytic infiltration to fibrous replacement of the thyroid tissue) occur in the cells of the endocrine glands. It develops gradually - as the destructive changes in the thyroid tissue increase, hypothyroidism may develop.
– Myxedema. This is condition resulting from insufficient thyroid hormones production. It is distinguished by severe water retention in the body and welling of organs and tissues.
– Cretinism. It is a congestive condition caused by inherited deficit of thyroid hormones production that causes delayed physical and mental development in children.
– Diffuse toxic goiter. It is an autoimmune disease caused by excessive secretion of thyroid hormones by diffuse thyroid tissue, which leads to poisoning by these hormones called thyrotoxicosis. Diffuse toxic goiter is characterized by a triad: hyperthyroidism, goiter and exophthalmos (protruding eyes).
– Thyroid adenoma. This is a benign tumor characterized by the appearance of a node in the thyroid gland against the background of its normal or increased function. They are divided into 3 types: papillary, follicular and adenomas from Gürtle cells. Follicular adenomas are more common and are likely to function autonomously.
– Thyroid cancer. Malignant tumor of the thyroid gland, developing from follicular or from C-cells. Depending on the histopathological structure, they are classified as papillary, follicular, medullary and anaplastic. Most common are papillary and follicular carcinomas. It usually occurs symptomless and is diagnosed when small nodes are found by a patient in the neck.
What are symptoms of thyroid gland disease?
The symptoms of thyroid diseases differ as the diseases themselves are basically based on two opposite factors – the overproduction of hormones or their deficiency. Here we list the symptoms for different disorders.
Hypothyroidism or insufficiency of thyroid hormones is frequently manifested in:
– General weakness;
– Decreased performance and fast fatigability;
– Decreased memory;
– Dry skin;
– Puffiness of the face and swelling of the extremities;
– Rough voice;
– Brittle nails;
– Hair loss;
– Weight gain with low appetite;
– Constipation, other symptoms.
The severity of symptoms of hypothyroidism depends largely on the cause of the disease, the degree of thyroid insufficiency, and the individual characteristics of the patient.
Hyperthyroidism (Thyrotoxicosis) or overproduction of thyroid hormones is associated with:
– Metabolic changes. Increased basal metabolic rate and weight loss are observed despite good appetite and adequate food intake;
– Sweating and intolerance of heat;
– Often reversible hyperglycemia;
– Enlarged thyroid gland;
– Heart rate increases;
– Persistent sinus tachycardia occurs with a frequency of 120 per minute and more (not disappearing during sleep and difficult to treat with cardiac glycosides);
– Palpitations in the neck, head and abdomen;
– Other arrhythmias due to increased myocardial excitability, such as atrial fibrillation and flutter;
– A tendency of increased systolic blood pressure and lowered diastolic blood pressure (high pulse pressure);
– Symptoms of chronic heart failure;
– Increased appetite;
– Bouts of abdominal pain;
– In severe cases - reversible liver damage (increase in size, pain, jaundice possible);
– Skin and hair changes. The skin is warm and moist due to vasodilation of peripheral vessels and increased sweating. Characterized by thin, silky hair, possible early gray hair;
– Pathological distractibility;
– Mild memory impairment;
– In women - menstrual disorders (up to amenorrhea)
– In men - reduced potency, possible gynecomastia.
Autoimmune thyroiditis is associated with:
– Local or diffuse (most often symmetric) increased density of the thyroid gland;
– Occurrence of nods in the thyroid;
– Trouble swallowing and breathing
– Moderate pain in the area of the thyroid gland.
Myxedema is associated with:
– Dry and pale skin;
– Swelling of the face and limbs;
– Brittleness and hair loss;
– Decreased blood pressure;
– Elevated lipoprotein cholesterol level;
– Hypochromic anemia.
Cretinism is manifested in:
– Retardation of physical development;
– Delayed growth and change of teeth;
– Prolonged nonclosure of the cranium of the skull;
– Coarse facial features (due to the swelling of soft tissues): a wide, flat (“square”) nose with a sticking of its back, eyes are located far apart (ocular hypertelorism);
– Big tongue (often it does not fit in the mouth), disproportionate body structure: short limbs, large head, thick and rough skin;
– Underdeveloped secondary sexual characteristics;
– Mental and mental disorders (even idiocy);
– Small stature (often dwarfism).
Diffuse toxic goiter is manifested in:
– Exophthalmos (bulging eyes);
– Weight loss despite increased appetite;
– Heat intolerance;
– Increased basal metabolism;
– Premenopausal women may have a decrease in the number and frequency of periods (oligomenorrhea) up to complete lack of menstruation;
– Arterial hypertension, increased pulse pressure (the difference between systolic and diastolic pressure);
– Chronic heart failure with peripheral edema;
– Increased sweating;
– Thyroid acropachia (specific changes of the nails);
– Onycholysis (destruction of the nails);
– Swelling in the legs;
– Proximal myopathy (difficulty getting up from a chair or squatting);
– Tendon reflexes hyperactivity;
– Nausea and vomiting (relatively rare).
Thyroid adenoma is manifested in:
– The appearance of a benign node in the thyroid gland;
– Thyroid cancer is, in most cases, asymptomatic. Most often, the first sign of thyroid cancer is the appearance of a nodular formation in the area of the thyroid gland or an increase in the cervical lymph nodes. However, thyroid nodules are found in many adults, and less than 5% of the number of nodes is malignant. Sometimes the first sign of a disease is an enlarged lymph node. Later symptoms are pain in the front of the neck and a change in voice. Typically, thyroid cancer is detected in individuals with normal thyroid function, but signs of hyperthyroidism or hypothyroidism can be combined with a larger or metastatic well-differentiated tumor. Thyroid nodules are of particular concern when identified in individuals under 20 years of age. At this age, the presence of benign nodes is less likely, therefore the probability of their malignancy is much higher.
What causes thyroid diseases?
There is a variety of reasons that can induce the onset of thyroid gland dysfunction, they include:
Hypothyroidism (underactive thyroid) can be induced by:
– Hypo- or aplasia of the thyroid gland;
– Congenital disorders of the synthesis of thyroid hormones;
– Nutrition (iodine deficiency, excess of thiocyanates present in cabbage, turnips, cassava, excess calcium and lithium ions that block iodine uptake);
– Medical actions (removal of the gland, radiation therapy, medication);
– Defect synthesis and transport of tiroliberin from the hypothalamus to the pituitary gland;
– It is associated with the inactivation of T3 and T4 circulating in the blood, TSH with autoantibodies, proteases in sepsis, pancreatitis, shock;
– Low sensitivity of target cell receptors to hormones;
– A possible cause is the deiodination of hormones in the peripheral blood.
Hyperthyroidism (overproduction of thyroid hormones) can be induced by:
– An autoimmune diseases including predominantly Graves' disease.
– Toxic thyroid adenoma as a result of iodine deficiency;
– Toxic multinodular goiter;
– Uncontrollable use thyroid hormone medicines;
– Use of Amiodarone, an antiarrhythmic drug structurally similar to thyroxine;
– Postpartum thyroiditis;
– A struma ovarii is a rare form of monodermal teratoma;
– Excess iodine consumption.
Hashimoto's thyroiditis or chronic lymphocytic thyroiditis can occur in people with risk factors such as:
– Genetic predisposition;
– Autoimmune diseases;
– High iodine intake;
– Selenium deficiency;
– Infectious diseases;
– Some medications.
Myxedema risk factors include:
– Overproduction of thyroid hormones;
– Insufficient production of thyroid hormones;
– Overconsumption or insufficient consumption of iodine.
Cretinism develops due to:
– Hereditary factor (reaction of thyroid-stimulating hormone);
– Disorders of embryonic development of the thyroid gland;
– Hypoplasia of the thyroid gland and athyreosis (absence of the thyroid gland);
– Ectopia of the thyroid gland;
– Endemic goiter transferred by the mother during pregnancy.
– Iodine and selenium deficiencies necessary for the synthesis of thyroid hormones.
Toxic diffuse goiter or Graves’ disease occurs due to:
– Genetic predisposition;
– Infectious diseases that trigger the inherited proneness to the disease.
Thyroid adenoma can be caused by:
– Genetic mutation.
Thyroid cancer is presumably caused by:
– Environmental factors such as exposure to ionizing radiation;
– Genetic predisposition;
– Other thyroid dysfunctions.
Who can develop the disease of the thyroid?
Although almost anyone can develop the diseases of the thyroid gland, the risk groups are:
– Women as they are more predisposed to the imbalance of thyroid hormones. Especially pregnant women or women in menopause;
– Kids and adolescents who need more resources for growth and the endocrine system sometimes cannot meet the needs;
– Individuals over 50 years of age as since this age the aging process is intensive and the body gets more sensitive;
– People who live in regions with low or excessive iodine levels in food;
– People who have family history of thyroid diseases.
How are the diseases of thyroid gland diagnosed?
The assessment of the thyroid gland condition is made based on a number of features some of which can be identified visually, some with instruments, and others by the blood tests.
– Examination and palpation.
This is the first thing that begins the examination of the thyroid gland: the doctor needs to examine and feel the neck, and to assess the overall appearance of the patient. This allows approximately to determine the size of the thyroid gland, the presence and localization of nodes in it, the mobility of the gland when swallowing, the size of the lymph nodes. Puffiness of the face and stinginess of facial expressions, and vice versa, an emaciated person with an anxious look may also indicate problems with the thyroid gland.
Instrumental methods include:
An instrumental examination of the thyroid gland is primarily necessary if cancer is suspected. It also evaluates the general condition of the organ, its size, symmetry of the lobes, and functional abilities of the tissues.
– Ultrasound is the main instrumental method, which allows determining the size of the thyroid gland without radiation exposure and calculating its volume, mass and degree of blood supply with great accuracy. It also establishes the presence of nodes and cystic lesions.
– X-ray of the neck and chest confirms or exclude thyroid cancer and the presence of lung metastases. Also it shows squeezing or displacement of the trachea and esophagus with retrosternal goiter.
– Computed tomography is specifying a detailed radiographic method that combines the advantages of ultrasound and conventional X-ray. It allows performing targeted biopsy of the nodes, but it is used less often than other methods because of the high cost of the equipment and the procedure itself.
– Scintigraphy is a radiological research. The day before the procedure, the patient must swallow a capsule with a radioactive isotope of iodine. It is also possible to introduce the drug in the vein. Then, with the help of a special device, the distribution of the administered substance in the thyroid gland is investigated. Thus, it is possible to determine the functional activity of the tissues, which other methods do not allow. If the doctor says that a full examination of the thyroid gland will be required, it will most likely include scintigraphy.
– Magnetic resonance imaging allows getting a three-dimensional image of the thyroid gland without radiation exposure and contrast agents, but is informatively comparable to ultrasound and is not the main diagnostic method. Mainly prescribed for retrosternal goiter.
– Biopsy. For any diffuse or nodular enlargement of the thyroid gland (goiter), a biopsy is required to exclude or confirm cancer. In the diagnosis of thyroid diseases, a combination of biopsy and ultrasound is considered the gold standard. Tissue samples are taken from three to five points.
– Laryngoscopy. It is carried out mainly before surgery to remove a thyroid cancer. The procedure is an introduction to the larynx of a thin tube - a laryngoscope - through which the wall of the larynx is illuminated and examined to check whether the volume of movement of the vocal cords due to the tumor is not disturbed. This reduces the likelihood of complications in the vocal cords after surgery.
Laboratory methods include:
For a complete examination of the thyroid gland, blood tests are important, the results of which make it possible to judge the shortage or excess of certain hormones. Depending on the data obtained, drug therapy is prescribed. If there are no other appointments of the endocrinologist, one month prior to the procedure the administration of thyroid hormones is excluded, two or three days before the tests the administration of iodine-containing drugs should be paused. On the eve it is necessary to exclude radiographic procedures, physical and emotional stress. Be sure to warn your doctor if you are taking any medications. They can affect the result of the analysis, and it will have to be repeated.
How are the diseases of thyroid gland treated?
– Hypothyroidism (underactive thyroid) treatment is based on the differential diagnosis. In the complex treatment, substitution therapy with cattle thyroid formulations or, more often, with synthetic thyroid hormones (thyroidin, triiodothyronine, thyroxin, thyroid, thyrotome-forte, thyreocomb), and medicines that improve metabolism such as Synthroid by Abbott pharmaceuticals are used. The dose is determined individually in each case.
– Hyperthyroidism is treated with the thyrostatic formulations that suppress the secretory activity of the thyroid gland (Tiamazol). Besides, a diet with sufficient content of proteins, fats and carbohydrates, replenishment of vitamin deficiencies (fruits, vegetables), and mineral salts (milk and lactic acid products as a source of calcium salts) is prescribed. It is also advised to limit the foods and dishes that excite the cardiovascular system and central nervous system (strong tea, coffee, chocolate, spices).
Hashimoto's thyroiditis is treated with the use of:
– In the presence of hypothyroidism, thyroid hormone formulations;
– Surgery (only for fast-growing goiter, compression of the trachea or neck vessels due to an enlarged thyroid gland, and suspicion of cancer in the presence of nodules);
– Selenium formulations;
– Myxedema is treated with thyroid hormone replacement therapy (thyroidin, left-thyroxin, triiodothyronine), and symptomatic therapy;
– Cretinism in the early stages is completely compensated by taking thyroid formulations (thyroxin). But a major role in the early detection of the disease is played by screening newborns.
Toxic diffuse goiter (Graves' disease) is treated with:
– Use of Mercazolyl and methylthiouracil (or propylthiouracil);
– Radioiodine therapy;
– Thyroid adenoma;
It doesn’t require treatment except for when the nods are interfering with a normal life, grow fast or the functions of thyroid are disturbed. It is recommended to monitor the condition of the thyroid and make surgery if recommended.
Thyroid cancer is treated with:
– Radioiodine therapy;
– Hormone therapy to lower the level of thyroid stimulating hormone naturally produced by the pituitary.
How to prevent thyroid diseases?
– Do preventive examinations;
– Replace regular salt with iodized;
– Include seafood and other products with iodine content in your diet: grapes, beef, oats, eggs, and sea kale;
– Give up smoking: it is scientifically proven that smokers are more likely to have an enlarged thyroid gland and thyrotoxic goiter;
– Lose weight if you are overweight;
– Maintain healthy level of physical activity.
It is especially advised to follow these recommendations if you have family history of thyroid diseases and have other risk factors.