Thyroxine (Na)
Also known as: Levothyroxine (Na)
Thyroxine (Na) is the major hormone elaborated by the thyroid gland. Chemically itL-3, 5, 3', 5'-tetraiodothyronine. it's chief function is to increase the rate of cell metabolism. italso essential for the central nervous system maturation and regulates a number of other functions. itmainly used in the treatment of hypothyroidism.
Primary Characteristics
Thyroxine (Na) is also known as Levothyroxine (Na).
It is of Natural origin and belongs to Tyrosine.
It belongs to Thyroxine agonsit pharmacological group on the basis of mechanism of action and also classified in Thyroid Hormone pharmacological group.
Molecular Weight: 798.9 · pKa: 2.2, 6.5, 10.1 · Solubility in Water: 1 in 700 · Solubility in Alcohol: 1 in 300 · Non-proprietary name: Thyroxine (Na) · pH: 8.9.
Pharmacokinetics
Absorption: Thyroxine (Na) has an oral bioavailability is 57.5% (±17.5%).
Distribution: Thyroxine (Na) has a plasma protein binding is 99.97 %.
Elimination: it is metabolised via extensively in live,kidney,glands, plasma half-life is 7 days, renal excretion is 30 - 55 %.
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Indications
Thyroxine (Na) is primarily indicated in conditions like Acquired hypothyroidism, Congenital hypothyroidism, Cretinism, Hypothyroidism, Myxedema coma, Non-toxic goiter.
Contraindications
Thyroxine (Na) is contraindicated in conditions like Angina, Cardiac failure, Adrenal failure, Pituitary disease.
Dosage
Thyroxine (Na)'s dosage details are as follows:
| Dose | Single Dose | Frequency | Route | Instructions |
|---|---|---|---|---|
| Adult Dosage | ||||
| 75 ug | 75 ug | Every 24h | PO | Initially for 2 Weeks |
| 150 ug | 150 ug | Every 24h | PO | Maintenance for 6-8 Weeks |
| Paediatric Dosage (20kg) | ||||
| 5 ug/kg | 5 ug/kg | Every 24h | Oral | - |
| Neonatal Dosage (3kg) | ||||
| 7 mg/kg | 7 mg/kg | Every 24h | Oral | |
Drug Interactions
Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.
Side Effects
Thyroxine (Na) in overdosage may give rise to further complications which include Tachycardia , Weight loss , Sinus tachycardia , Diarrhoea , Cardiac arrhythmias, Insomnia , Agitation , Tremors , Heat intolerance .
Thyroxine (Na) produces potentially life-threatening effects which include Myocardial infarction, Exacerbation of angina, Exacerbation of cardiac arrhythmias. Careful monitoring is needed with proper medical management.
The signs and symptoms that are produced after acute overdosage of Thyroxine (Na) are Cardiovascular collapse, Thyrotoxicosis , Hyperpyrexia, Coma.
Thyroxine (Na) is known to cause more or less tolerable side effects which are usually transient. These include Alopecia, Amenorrhea, Anorexia , Atrial fibrillation, Diaphoresis, Irritability.
Warnings / Precautions
Interference in Pathology
Thyroxine (Na) may interfere in the diagnosis of Test for Hypothyroidism .
Available Brands
Storage Conditions
Drug Classification
- 1.18.8 — Thyroid & antithyroid preparations