Levothyroxine Sodium (L-Thyroxine) 0.1 mg Tablet

Package:

100 tablets of 0.1 mg each.

Indications:

Used in the treatment of simple (euthyroid) goiter and hypothyroidism of all etiologies (myxedema, cretinism, and simple hypothyroidism in patients of all ages) (excluding transient hypothyroidism in the recovery phase of subacute thyroiditis), for the purpose of pituitary TSH suppression, in cases of primary atrophy and partial or total absence of the thyroid gland, for diagnostic purposes in thyroid suppression tests, to prevent post-operative recurrence, and in primary hypothyroidism due to functional insufficiency, thyroiditis, secondary or tertiary hypothyroidism.

Contraindications:

Generally contraindicated in cases of undiagnosed and untreated adrenal cortex insufficiency (in which case this insufficiency is treated first, followed by the addition of T4 therapy after a short period of time), untreated thyrotoxicosis, and hypersensitivity to levothyroxine.

Warnings:

Can be used during pregnancy without risk of harm to the fetus. The definitive effect on lactation is not known. Although it is excreted in small amounts in breast milk, it is generally accepted that it will not have an effect on the baby at therapeutic doses.

Side Effects:

May cause changes in appetite and menstrual period, breast pain, diarrhea, tremor, headache, irritability, restlessness, tachycardia and cardiac arrhythmias, sensitivity to heat, insomnia, excessive sweating, vomiting, and weight loss, which can lead to symptoms of hyperthyroidism.

Drug Interactions:

Cholestyramine should be taken at least 4 hours apart from levothyroxine. In patients with diabetes mellitus, levothyroxine may increase the need for insulin or oral hypoglycemic medications. Thyroid preparations may increase the activity of anticoagulants. Levothyroxine may decrease the effect of digitalis preparations. Estrogens can increase serum levels of thyroxine binding globulin. Phenobarbital can theoretically increase hepatic degradation of levothyroxine. Levothyroxine therapy should not be administered intravenously during phenytoin therapy. Thyroid preparations may increase the effects of sympathomimetic amines or tricyclic antidepressants. Drugs that partially or completely inhibit the peripheral conversion of T4 to T3, beta blockers, high-dose propylthiouracil, certain X-ray contrast agents, and dexamethasone may reduce the therapeutic effect of levothyroxine.

Dosage Recommendations:

1 tablet daily is started in the treatment of simple goiter, thyroiditis and post-operative recurrence prevention and the dose can be increased up to 2 tablets daily. In rare cases, higher doses may be used. The daily drug requirement in hypothyroidism can vary from patient to patient. It should generally be started with ½ tablet and increased by ¼ tablet every 2-3 weeks. In cases of long-term myxedema (especially if there are cardiovascular disorders), the dose should be adjusted carefully. In such cases, it should be started with ¼ tablet and the daily maximum dose should be adjusted to 100-200 mg thyroxine (T4). At the end of the first four weeks of treatment, the dose of the preparation should be readjusted according to clinical and laboratory findings.