Levothroid (levothyroxine sodium) is a synthetic thyroid hormone replacement medication indicated for the treatment of hypothyroidism. It is bioequivalent to the endogenous hormone thyroxine (T4) produced by the thyroid gland, providing a consistent and reliable method for restoring euthyroid states in patients with thyroid hormone deficiency. This medication is formulated to address the root metabolic dysfunction caused by an underactive thyroid, offering a fundamental solution for long-term endocrine health management. Proper use under medical supervision can significantly improve quality of life by normalizing metabolic processes.

Features

• Contains levothyroxine sodium, a synthetic form of the T4 hormone
• Available in multiple strengths for precise dosage titration (e.g., 25 mcg, 50 mcg, 75 mcg, 88 mcg, 100 mcg, 112 mcg, 125 mcg, 137 mcg, 150 mcg, 175 mcg, 200 mcg)
• Manufactured under strict USP standards for consistent potency and purity
• Scored tablets allow for accurate splitting when dose adjustments are necessary
• Long-established formulation with extensive clinical history and safety data

Benefits

• Effectively normalizes thyroid-stimulating hormone (TSH) levels, restoring metabolic equilibrium
• Alleviates symptoms of hypothyroidism such as fatigue, weight gain, cold intolerance, and cognitive fog
• Supports cardiovascular health by maintaining normal heart rate and cholesterol levels
• Promotes healthy energy metabolism, improving overall daily functioning and well-being
• Prevents long-term complications of untreated hypothyroidism, including myxedema and goiter
• Offers predictable pharmacokinetics for stable hormonal levels with once-daily dosing

Common use

Levothroid is primarily prescribed for the treatment of hypothyroidism, a condition characterized by insufficient production of thyroid hormones by the thyroid gland. It is also used as suppressive therapy in the management of certain thyroid cancers and euthyroid goiters. In some cases, it may be administered as a diagnostic tool in thyroid suppression tests. The medication is suitable for lifelong replacement therapy in cases of permanent hypothyroidism, including post-thyroidectomy states or after radioactive iodine treatment.

Dosage and direction

The dosage of Levothroid is highly individualized based on the patient’s age, weight, clinical condition, thyroid function tests, and concurrent medications. For otherwise healthy adults under 50 with recent-onset hypothyroidism, the typical starting dose is 1.6 mcg/kg body weight per day. For patients with long-standing hypothyroidism, cardiovascular disease, or elderly patients, initial doses are typically lower (25-50 mcg daily) with gradual titration.

Administer Levothroid orally as a single daily dose, on an empty stomach, at least 30-60 minutes before breakfast. Tablets should be taken with a full glass of water. Consistency in timing and conditions of administration is crucial for maintaining stable serum levels. Dosage adjustments should be based on periodic assessment of TSH levels, typically measured 4-6 weeks after initiation or dose change.

Precautions

Patients should be monitored for signs of thyrotoxicosis, particularly during dose titration. Those with cardiovascular disease require careful monitoring as thyroid hormone increases myocardial oxygen demand. Levothroid may exacerbate underlying adrenal insufficiency; adrenal function should be assessed before initiation. Diabetic patients may require adjustment of antidiabetic medication as thyroid hormone can affect glucose metabolism. Bone mineral density should be monitored in postmenopausal women on long-term therapy. Pregnancy alters thyroid hormone requirements, necessrequent monitoring and possible dose adjustments.

Contraindications

Levothroid is contraindicated in patients with uncorrected adrenal insufficiency, untreated thyrotoxicosis, and acute myocardial infarction. It should not be used for weight loss in euthyroid patients. Hypersensitivity to any component of the formulation is an absolute contraindication. The medication is not indicated for the treatment of transient hypothyroidism during the recovery phase of subacute thyroiditis.

Possible side effect

Most side effects are dose-related and indicate excessive dosage. Common adverse reactions include palpitations, tachycardia, cardiac arrhythmias, angina pectoris, tremors, headache, insomnia, nervousness, irritability, muscle weakness, cramps, increased appetite, weight loss, diarrhea, heat intolerance, and menstrual irregularities. Allergic reactions, though rare, may include skin rash, urticaria, and pruritus. Partial hair loss may occur during initial months of therapy, typically transient in nature.

Drug interaction

Several medications significantly affect Levothroid absorption or metabolism. Bile acid sequestrants (cholestyramine, colestipol), calcium carbonate, aluminum-containing antacids, iron supplements, sucralfate, and proton pump inhibitors may decrease absorption—administer at least 4 hours apart. Estrogens and estrogen-containing oral contraceptives may increase thyroxine-binding globulin, potentially requiring dose adjustment. Rifampin, carbamazepine, phenytoin, and barbiturates may increase hepatic metabolism of levothyroxine. Levothroid may potentiate the effects of anticoagulants, requiring more frequent monitoring of coagulation parameters.

Missed dose

If a dose is missed, it should be taken as soon as possible on the same day. If remembered at the time of the next dose, the missed dose should be skipped; doubling the dose is not recommended. Maintain the regular dosing schedule the following day. Consistent daily administration is important for stable thyroid levels, but occasional missed doses are unlikely to cause significant clinical consequences in most patients.

Overdose

Symptoms of overdose are those of thyrotoxicosis: tachycardia, cardiac arrhythmias, chest pain, tremors, restlessness, headache, insomnia, excessive sweating, heat intolerance, and fever. In severe cases, cardiac failure, shock, psychosis, and coma may occur. Treatment is supportive and symptomatic. Beta-blockers may be used to control adrenergic symptoms. There is no specific antidote. Hemodialysis is not effective for removing thyroid hormone from circulation due to high protein binding.

Storage

Store Levothroid tablets at controlled room temperature (20-25°C or 68-77°F) in their original container with the lid tightly closed. Protect from light, moisture, and excessive heat. Keep out of reach of children. Do not use tablets that are discolored or show signs of deterioration. Do not store in bathroom cabinets where humidity levels fluctuate. Discard any unused medication after the expiration date printed on the packaging.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Levothroid is a prescription medication that should be used only under the supervision of a qualified healthcare provider. Dosage and treatment duration should be determined by a physician based on individual patient needs and regular monitoring of thyroid function tests. Never adjust your dose without consulting your healthcare provider. The information provided here may not include all possible uses, directions, precautions, or interactions.

Reviews

“After struggling with unexplained fatigue for years, Levothroid restored my energy levels within weeks. My TSH levels have remained stable at the 50 mcg dose, and I appreciate the consistent quality of this formulation.” - M.B., age 42

“As an endocrinologist with twenty years of practice, I find Levothroid to be a reliable and predictable thyroid replacement option. The multiple strengths available allow for precise titration, which is crucial for optimal patient outcomes.” - Dr. R.S., MD

“The scored tablets make dose adjustments straightforward. After my thyroidectomy, we’ve been able to fine-tune my dosage with minimal fluctuations in my lab values.” - T.K., age 58

“I experienced some initial hair shedding when starting treatment, but my endocrinologist reassured me this was temporary. After three months, it resolved completely, and my overall wellbeing has improved dramatically.” - L.J., age 35