Novothyral (Tablets) Instructions for Use

ATC Code

H03AA03 (Levothyroxine in combination with liothyronine)

Active Substances

Levothyroxine sodium (Rec.INN registered by WHO)

Liothyronine (Rec.INN registered by WHO)

Clinical-Pharmacological Group

Thyroid hormone preparation

Pharmacotherapeutic Group

Thyroid agent

Pharmacological Action

A combined drug for replacement therapy, contains L-isomers of T4 and T3, replenishes the deficiency of thyroid hormones.

It has anabolic and catabolic effects, activates fat metabolism, increases the functional activity of the cardiovascular system and CNS.

In large doses, it inhibits the production of TRH by the hypothalamus and TSH by the pituitary gland.

More effective than levothyroxine.

The latent period of action of levothyroxine is 24-48 hours, liothyronine – 4-8 hours.

The optimal combination of drugs is 4:1 or 5:1.

Pharmacokinetics

When taken orally, Levothyroxine sodium is absorbed almost exclusively in the upper part of the small intestine.

Absorption is up to 80%.

Food intake reduces the absorption of levothyroxine.

C_max in blood serum is reached approximately 5-6 hours after oral administration.

Binding to plasma proteins is more than 99% (with thyroxine-binding globulin, thyroxine-binding prealbumin, and albumin).

In various tissues, about 80% of levothyroxine undergoes monodeiodination to form triiodothyronine and inactive products.

Thyroid hormones are metabolized mainly in the liver, kidneys, brain, and muscles.

A small amount of levothyroxine sodium undergoes deamination and decarboxylation, as well as conjugation with sulfuric and glucuronic acids (in the liver).

Metabolites are excreted in the urine and bile.

T_1/2 of levothyroxine is 6-7 days.

In thyrotoxicosis, T_1/2 is shortened to 3-4 days, and in hypothyroidism it is prolonged to 9-10 days.

Liothyronine. Absorption after oral administration is 95% (within 4 hours).

Binding to plasma proteins is high.

T_1/2 is 2.5 days.

Indications

Hypothyroidism (of various origins); deficiency of thyroid hormones; recurrence of goiter (prophylaxis after resection); euthyroid benign goiter; additional therapy of thyrotoxicosis with thyrostatic drugs after achieving a euthyroid state (not during pregnancy); thyroid cancer (suppressive therapy, after thyroidectomy – replacement).

ICD codes

Dosage Regimen

Determine the dosage individually based on disease etiology, clinical presentation, and laboratory parameters.

Administer orally, as a single daily dose, at least 30 minutes before breakfast. Take the tablet with a full glass of water.

For adults, the typical daily dose is 40-100 mcg of levothyroxine combined with 10-20 mcg of liothyronine.

Initiate therapy at the lower end of the dosage range, particularly in elderly patients and those with pre-existing cardiovascular disease.

Titrate the dose gradually, in small increments, at intervals of no less than 2-4 weeks. Base adjustments on clinical response and serum TSH, free T4, and T3 levels.

For children over 4 years of age and adolescents under 14, use a dose approximately half of the typical adult dose. Calculate the dose based on body surface area or body weight.

In cases of severe, long-standing hypothyroidism, start with an exceptionally low dose and increase very cautiously.

During pregnancy, monitor thyroid function closely, as dose requirements frequently increase and may require adjustment.

In patients with subclinical hypothyroidism, individualize the decision to treat and the initial dosage.

For suppressive therapy in thyroid cancer, use higher doses to maintain TSH suppression, as clinically indicated.

Adverse Reactions

From the cardiovascular system: progression of heart failure, angina pectoris.

Other: allergic reactions.

Contraindications

Hypersensitivity; myocardial infarction (acute, history); goiter in old age; acute myocarditis; cardiomyopathy; angina pectoris; adrenal insufficiency; chronic heart failure; coronary artery disease; severe atherosclerosis; arrhythmias; arterial hypertension; children under 4 years of age.

With caution

In cardiovascular diseases: coronary artery disease (atherosclerosis, angina pectoris class I-II, history of myocardial infarction), heart failure, arterial hypertension, tachycardia, tachyarrhythmia; in diabetes mellitus, diabetes insipidus, adrenal insufficiency, severe long-standing hypothyroidism, malabsorption syndrome; in elderly patients.

Use in Pregnancy and Lactation

Therapy for hypothyroidism should be continued during pregnancy and breastfeeding.

During pregnancy, an increase in the dose of the drug may be required due to an increase in the level of thyroxine-binding globulin.

There are no data on the occurrence of teratogenic and fetotoxic effects when using the drug in recommended therapeutic doses.

The use of the drug during pregnancy in excessively high doses may adversely affect the fetus and postnatal development.

The use of the drug in combination with antithyroid drugs during pregnancy is contraindicated, because the intake of levothyroxine sodium may require an increase in the dose of antithyroid drugs.

Since antithyroid drugs, unlike levothyroxine sodium, can cross the placental barrier, hypothyroidism may develop in the fetus.

During breastfeeding, the drug should be taken strictly in the recommended doses under medical supervision.

When using the drug in recommended therapeutic doses, the concentration of thyroid hormone secreted in breast milk is insufficient to cause hyperthyroidism and suppression of TSH secretion in the child.

Pediatric Use

Used in children over 4 years of age. Use is possible according to the dosage regimen.

Geriatric Use

Contraindicated in the presence of goiter in old age.

Special Precautions

In coronary artery disease, heart failure, or tachyarrhythmias, more frequent monitoring of thyroid hormone levels is required.

Particular caution should be exercised when prescribing the drug to elderly patients.

Treatment in them should be carried out with lower doses.

Use in patients with diabetes mellitus, diabetes insipidus, or adrenal cortex insufficiency may lead to an increase in the severity of symptoms of these diseases.

In hypothyroidism due to pituitary damage, it is necessary to determine whether there is concomitant adrenal cortex insufficiency.

In this case, replacement therapy with corticosteroids should be started before starting treatment of hypothyroidism with thyroid hormones to avoid the development of acute adrenal insufficiency.

Drug Interactions

Enhances the effect of indirect anticoagulants, which may require a reduction in their dose.

Concomitant use with tricyclic antidepressants may lead to an enhancement of the antidepressant effect.

May increase the need for insulin and oral hypoglycemic drugs.

More frequent monitoring of blood glucose levels is recommended during the initiation of treatment, as well as when changing its dosage regimen.

Reduces the effect of cardiac glycosides.

With simultaneous use, cholestyramine, colestipol and aluminum hydroxide reduce the plasma concentration of the drug by inhibiting its absorption in the intestine.

With simultaneous use with anabolic steroids, asparaginase, tamoxifen, pharmacokinetic interaction at the level of protein binding is possible.

With simultaneous use with phenytoin, salicylates, clofibrate, furosemide in high doses, the content of thyroid hormones not bound to plasma proteins increases.

Estrogen-containing agents increase the content of thyroxine-binding globulin, which may increase the need for this drug.

Somatotropin when used concomitantly with the drug may accelerate the closure of epiphyseal growth zones.

Taking phenobarbital, carbamazepine and rifampicin may increase the clearance of levothyroxine and require an increase in the dose of the drug.

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.