Liothyronine

Overview

It acts faster and wears off sooner than levothyroxine.

What it's used for

• Underactive thyroid (usually with levothyroxine)
• Thyroid testing and some thyroid cancer care

How to take it

• Take it at the same time each day.
• Separate it from calcium, iron, and antacids by 4 hours.

Your dose depends on your health and other medicines. Always follow your prescription label, and ask your pharmacist if anything is unclear.

Side effects

Common side effects

• Fast heartbeat
• Nervousness
• Trouble sleeping
• Sweating

Warnings

• Boxed warning: not for weight loss; large doses can be dangerous.

Other medicines, foods, and alcohol

• Calcium, iron, and antacids lower absorption.
• Blood thinners may need monitoring.

Tell your provider and pharmacist about every medicine, vitamin, and supplement you take.

Pregnancy and breastfeeding

Talk with your provider; thyroid needs change in pregnancy.

Missed doses, overdose, and storage

If you miss a dose

Take it as soon as you remember, unless it's almost time for your next dose. Then skip the missed dose. Don't take two doses at once.

If someone takes too much

Call Poison Control at 1-800-222-1222 or get help online at poison.org. Call 911 if the person collapses, has a seizure, has trouble breathing, or can't be woken.

Storing it

Store at room temperature, away from heat and moisture (not in the bathroom), and out of reach of children and pets.

Conditions it's used for

• Underactive thyroid (hypothyroidism)