Levothyroxine
Also sold as: Euthyrox, Thyronorm, Eltroxin
Prescription neededThyroid medicines
Comes as:Tablet
Usual adult dose
Dose is set by your doctor and adjusted by blood tests; a usual adult starting dose is 25 to 100 micrograms once a day, lower in older people and heart patients. Take on an empty stomach, 30 to 60 minutes before breakfast, at the same time every day.
Your doctor may give you a different dose. Children's doses depend on weight.
Side effects
Common
- usually none at the right dose; too high a dose: fast heartbeat
- sweating
- shaking
- weight loss
- trouble sleeping
Serious — get help
Stop taking it and see a doctor straight away if you notice:
- chest pain
- very fast or irregular heartbeat
- severe allergic reaction
Do not take it, or take care, if
- Overactive thyroid that is not treated
- Recent heart attack or untreated adrenal problem
- Heart disease or older age (start with a low dose)
- Do not use for weight loss
Interactions
Medicines that can react with this one.
Moderate10 medicinesTake together only with care. Ask your doctor or pharmacist.
- Aluminium hydroxide + Magnesium hydroxide
Antacids reduce levothyroxine absorption; take them at least 4 hours apart.
- Calcium carbonate