Levothyroxine Sodium
Generic Details
Generic Name
Levothyroxine-sodium
Other Names
- Synthroid
- Levoxyl
- Eltroxin
Drug Class
- Thyroid hormone
Chemical Formula
C15H10I4NNaO4
Molecular Weight
798.85 g/mol
Mechanism of Action
- Acts as a synthetic form of thyroxine (T4) which is converted to triiodothyronine (T3) in the body. It regulates metabolic processes and influences the growth and development of tissues.
Indications
- Hypothyroidism
- Thyroid cancer (after thyroidectomy)
Common Dosage Forms
- Tablet
- Capsule
Typical Dosage
- 25-200 mcg once daily in the morning on an empty stomach
Pediatric Dosage
- Dose varies based on weight and age, consult a healthcare provider
Geriatric Dosage
- Lower starting doses may be required for the elderly
Side Effects
- Palpitations
- Weight loss
- Tremors
- Headache
- Nervousness
Contraindications
- Untreated thyrotoxicosis
- Acute myocardial infarction
- Uncorrected adrenal insufficiency
Pregnancy Category
- A
Lactation Safety
- Considered safe while breastfeeding
Drug Interactions
- Warfarin
- Phenytoin
- Digoxin
Overdose Symptoms
- Chest pain
- Increased heart rate
- Fever
- Excessive sweating
Antidote for Overdose
- Activated charcoal
- Cholestyramine
Storage Conditions
- Store at room temperature below 25°C (77°F)
Pharmacokinetics
- Absorption: Absorbed in the upper small intestine
- Distribution: Mainly bound to serum proteins
- Metabolism: Liver
- Excretion: Primarily in urine
Precautions
- Dose adjustments may be needed in patients with cardiovascular disease or diabetes
Warnings
- Regular monitoring of thyroid function tests is essential during treatment