Levothyroxine Sodium

Levothyroxine sodium is a medication taken by people who have hypothyroidism, or an underactive thyroid. Levothyroxine sodium is a man-made form of thyroid hormone that replaces the hormone that the body is not able to make. It can also be used to decrease the size of a thyroid gland that is too big (called a goiter).

Levothyroxine sodium comes in two forms. The tablet form is taken by mouth every day. The IV or intravenous form of this medicine is only given in hospitals in an emergency situation.

Children should take the tablet with water on an empty stomach. The tablet can be crushed and mixed with a small amount of formula or water when given to a small child or infant. Do not mix the crushed tablet with an entire bottle of formula. Older children usually take the medicine an hour before or two hours after breakfast.

There are some foods that might not allow all of the medicine to be absorbed. Please let your doctor know if your child is taking a soy formula or has a diet high in soy products.

Antacids, iron and calcium supplements should be taken four hours before or after the thyroid medication.

Do not change brands of thyroid medication without talking to your child's healthcare provider. If the health insurance company or pharmacist wants to change brands, please tell your child's endocrine healthcare provider.

Do not use medicine after the expiration date on the bottle / package. Keep this medication out of the reach of children.

There are not many side effects with thyroid medication, but you should call your child's healthcare provider if a skin rash or hives develop while taking the medication.

If your child experiences the following symptoms, he / she may need to have the healthcare provider change the dose:

  • Trouble sleeping
  • Feeling tired
  • Trouble concentrating
  • Loose stools
  • Constipation

Call your child's healthcare provider right away if he / she has:

  • Chest pain
  • Trouble breathing
  • Fast heart beat
  • General weakness
  • Shakiness or tremors
  • Skin rash

These symptoms may be a sign of too much or too little medicine and should be corrected as soon as possible.


Last Updated 11/2014