Levothyroxine

Levothyroxine

Levothyroxine, a crucial hormone replacement therapy, plays a vital role in managing thyroid disorders. This synthetic thyroid hormone helps restore balance to the body's metabolism, energy levels, and overall wellness. Levothyroxine tablets are prescribed to patients with underactive thyroid glands, a condition known as hypothyroidism, to replace the hormone their bodies can't produce naturally. Let's explore the essential aspects of levothyroxine medication.

What is Levothyroxine?

Levothyroxine is a synthetic thyroxine (T4), a hormone naturally generated by the thyroid gland. It plays a crucial role in treating hypothyroidism, an endocrine condition where the thyroid gland doesn't produce enough thyroid hormone. This medicine helps restore normal thyroid hormone levels in the body, which are essential for maintaining proper mental and physical activity.

Levothyroxine tablet Uses

The primary use of levothyroxine is to treat hypothyroidism. This medication replaces or provides additional thyroid hormone, which is crucial for maintaining normal bodily functions.
There are three main types of hypothyroidism that levothyroxine treats:

• Primary Hypothyroidism: This type occurs due to problems in the thyroid gland itself, often caused by an autoimmune condition called Hashimoto's thyroiditis or after thyroid gland removal.
• Secondary Hypothyroidism: This type results from issues in the pituitary gland, leading to decreased thyroid-stimulating hormone (TSH) production.
• Tertiary Hypothyroidism: A rare form where the problem lies in the hypothalamus, causing reduced production of thyroid-releasing hormone (TRH).

Levothyroxine is also beneficial in other types of thyroid disorders, such as certain thyroid cancers.

How to Use Levothyroxine Tablet

• Patients should take the medication in the morning at least 30 to 60 minutes before breakfast. 
• If you are using oral liquid form, take it on an empty stomach at least 15 minutes before breakfast. You can mix it with water or take it directly into the mouth. If mixed with water, drink immediately and rinse the glass with more water to ensure all medicine is consumed.
• It's crucial to avoid certain foods when taking levothyroxine:
  • Cotton seed meal, dietary fibre, soybean flour, and walnuts may decrease absorption.
  • Avoid grapefruit and grapefruit juice.
• Individuals should take medications such as antacids, cholesterol-lowering drugs, and stomach medicines at least 4 hours before or after levothyroxine.
• Do not stop taking levothyroxine without consulting your endocrinologist.

Side Effects of levothyroxine tablet

Common side effects of levothyroxine include:

• Increased appetite
• Weight loss
• Heat sensitivity
• Excessive sweating
• Headache
• Hyperactivity
• Nervousness or anxiety
• Irritability
• Mood swings
• Trouble sleeping
• Tiredness
• Tremors
• Muscle weakness
• Changes in menstrual periods
• Temporary hair loss
• Diarrhoea
• Vomiting
• Stomach cramps
• Bone pain

More serious side effects include:

• Chest pain or discomfort
• Difficulty breathing or breathlessness
• Swelling of the eyes, face, lips, tongue, or throat
• Irregular heartbeat
• Severe headache
• Sudden loss of coordination
• Confusion or disorientation

Precautions

Patients taking levothyroxine should be aware of several essential precautions, such as:

• Precaution For Weight Treatment: Levothyroxine should not be used for weight loss or obesity treatment, as it is ineffective for this purpose and may cause serious side effects if taken in large amounts. 
• Precaution For Diabetics: Diabetic patients must closely monitor their blood or urine sugar levels and inform their doctor of any changes. 
• Precaution For Pregnant Females: Pregnant women should notify their doctor immediately, as they may require a larger dose of levothyroxine during pregnancy.
• Precaution For Post-menopausal Females: Post-menopausal women or those using levothyroxine long-term may experience bone loss, potentially leading to osteoporosis. Patients should discuss any queries with their doctor.
• Signs to Look Out: It's essential to report any symptoms of excessive medication, such as rapid heartbeat, chest pain, nervousness, or changes in appetite, to a doctor immediately. Similarly, signs of severe hypothyroidism, like weakness, confusion, or difficulty breathing, require immediate medical attention.

Patients should not stop taking levothyroxine suddenly without consulting their doctor. Patients should avoid taking other medicines, including over-the-counter drugs and supplements, without first discussing them with their doctor.

How Levothyroxine Tablet Works

Levothyroxine is a synthetic substitute for thyroxine (T4). Thyroxine is a hormone naturally synthesised by the thyroid gland. It mimics the body's endogenous T4 production, making it an effective treatment for hypothyroidism.
When a person takes levothyroxine, it enters the bloodstream and travels to various tissues throughout the body. Once inside the cells, levothyroxine binds to thyroid receptor proteins within the cell nucleus. This binding initiates a series of events that directly influence DNA transcription, leading to increased body metabolism.
The effects of levothyroxine include:

• Enhanced gluconeogenesis
• Increased protein synthesis
• Mobilisation of glycogen stores

In peripheral tissues, some of the T4 from levothyroxine converts into T3, which is the more active form of thyroid hormone. T3 has a relative potency of about four times that of T4.
Levothyroxine helps regulate various bodily functions, including:

• Heart rate and cardiac output
• Body temperature
• Energy levels
• Metabolism of food

By restoring normal thyroid hormone levels, levothyroxine alleviates symptoms of hypothyroidism, such as slow speech, lack of energy, weight gain, hair loss, dry skin, and unusual sensitivity to cold.

Can I Take Levothyroxine with Other Medicines?

Separating levothyroxine from certain medications by 4 hours is essential to ensure optimal effectiveness.
Medicines and supplements to avoid within 4 hours of taking levothyroxine include:

• Antacids
• Bile acid sequestrants (colesevelam, cholestyramine, colestipol)
• Calcium supplements
• Ion exchange resins (kayexalate)
• Iron supplements
• Phosphate binders (calcium carbonate, ferrous sulphate, sevelamer, lanthanum)
• Sucralfate

Dosing Information

For adults and children over 12 years with complete growth and puberty, the initial dose is typically 1.6 to 1.7 micrograms (mcg) per kg of body weight per day. Older adults may require a lower dose. Children with incomplete growth and puberty usually need 2 to 3 mcg per kilogram of body weight daily.

Conclusion

Levothyroxine has a significant influence on the lives of millions grappling with thyroid disorders. This synthetic hormone replacement therapy is crucial in restoring balance to the body's metabolism, energy levels, and overall well-being. As we've explored, proper dosing, timing, and awareness of potential interactions are key to maximising this medication. Regular check-ups and open communication with healthcare providers ensure optimal thyroid health management.

FAQs:

1. What is levothyroxine used for?

Levothyroxine is primarily used to treat hypothyroidism. It is a medical condition where the thyroid gland does not produce enough thyroid hormone. It replaces or provides additional thyroid hormone, crucial for maintaining several body functions. 

2. Who needs to take levothyroxine?

People with an underactive thyroid gland (hypothyroidism) need to take levothyroxine. This condition includes individuals with primary hypothyroidism (a problem in the thyroid gland itself), secondary hypothyroidism (an issue in the pituitary gland), and tertiary hypothyroidism (a rare form). Patients with thyroid cancer may also require levothyroxine as part of their treatment.

3. Is it bad to use levothyroxine every day?

It is okay to use levothyroxine every day. In fact, daily use is necessary for most patients. 

4. Is levothyroxine safe?

Levothyroxine is generally safe when taken as prescribed. Long-term use of high doses may lead to the weakening of the bones (osteoporosis). It's crucial to have check-ups and blood tests to maintain the correct dosage and monitor for any potential issues.

5. Who Cannot use levothyroxine?

People with an overactive thyroid (thyrotoxicosis), untreated adrenal insufficiency, or recent heart problems such as a heart attack should not take levothyroxine. Patients with diabetes, heart disease, or blood clotting disorders should consult their doctor before starting treatment.

6. Is levothyroxine safe for kidneys?

Levothyroxine affects kidney function but can be used safely in patients suffering from chronic kidney disease (CKD). 

5. Can I take levothyroxine at night?

Yes, you can take levothyroxine at night. Some studies have shown that bedtime intake may improve thyroid hormone levels. This is because bowel motility is slower at night, allowing for better absorption. 

6. What is the best time to take levothyroxine?

Traditionally, levothyroxine has been taken in the morning on an empty stomach, half to one hour before breakfast. It helps prevent interference with its absorption from food or other medications. However, recent studies suggest that bedtime intake may be equally effective or even better for some patients.