About levothyroxin sodium
Thyroid hormone replacement
Used for
- Treats an underactive thyroid (hypothyroidism).
- Helps suppress thyroid-stimulating hormone after some thyroid cancers.
Usual adult dose
Usually 25–50 micrograms once daily initially; adjusted gradually according to blood tests. Many adults need 100–200 micrograms daily.
Usual dose in children
Dose is based on age, weight, and blood tests; infants and children require individualized daily dosing.
Common side effects
- If the dose is too high: palpitations, tremor, sweating, or nervousness.
- Headache, sleep problems, or muscle cramps.
- Temporary hair loss can occur, especially in children.
Important warnings
- Take consistently on an empty stomach; separate from calcium or iron by at least four hours.
- Dose changes take weeks to show their full effect; blood tests guide adjustments.
- Use caution with heart disease, older age, adrenal insufficiency, or untreated thyroid disorders.
- Not for weight loss; excessive doses can cause serious harm.
Pregnancy
Usually continued during pregnancy; requirements often increase, and thyroid blood tests need monitoring.
Breastfeeding
Compatible with breastfeeding at prescribed doses; adequate treatment supports normal milk production.
Interactions
- Calcium, iron, antacids, and some foods can reduce absorption.
- Warfarin effects may increase when thyroid levels normalize.
- Some seizure medicines and rifampicin can alter levothyroxine requirements.
- Biotin can interfere with thyroid blood tests.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.