Liotrix

Liotrix is a prescription medication used to treat hypothyroidism (low thyroid hormone). Liotrix is used in combination with antithyroid medication to treat thyrotoxicosis (excess thyroid hormone)

• Liotrix is available under various brand names: Thyrolar-1, Thyrolar-1/2, Thyrolar-1/4, Thyrolar-3

Common side effects of Liotrix include:

• Headache, tiredness, and mood changes.
• Tremors, feeling anxious.
• Fast heart rate increased blood pressure.
• Muscle weakness.
• Increased appetite.
• Stomach cramps.
• Hair loss; or
• Abnormal liver function tests.

Serious side effects of Liotrix include:

• Vomiting, diarrhea.
• Fever, swollen glands, itching, joint pain, or not feeling well.
• Flushing (sudden warmth, redness, or tingly feeling).
• Chest pressure spreading to your jaw or shoulder.
• Shortness of breath.
• Weak or shallow breathing.
• Headache, tremors, trouble sleeping, feeling nervous or irritable.
• Changes in weight or appetite.
• Changes in the menstrual periods.
• Severe headaches, ringing in the ears, dizziness, vision problems, pain behind the eyes.
• Thinking problems, trouble concentrating, poor academic performance; or
• (In a child or teenager) pain, stiffness, and trouble moving the legs.

Rare side effects of Liotrix include:

• None

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.
• Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult and pediatric dosage

Tablet, T3/T4

• Thyrolar 1/4 (15 mg): 3.1/12.5 mcg
• Thyrolar 1/2 (30 mg): 6.25/25 mcg
• Thyrolar 1 (60 mg): 12.5/50 mcg
• Thyrolar 2 (120 mg): 25/100 mcg
• Thyrolar 3 (180 mg): 37.5/150 mcg

Hypothyroidism

Adult dosage

• Initial: Levothyroxine 25 mcg/liothyronine 6.25 mcg once daily; a lower initial dose (levothyroxine 12.5 mcg/liothyronine 3.1 mcg) is recommended in patients with long-standing myxedema, especially if cardiovascular impairment coexists (if angina occurs, reduce dose). The dose may be increased in increments of levothyroxine 12.5 mcg/liothyronine 3.1 mcg every 2 to 3 weeks.
• Usual maintenance dose: Levothyroxine 50 to 100 mcg/liothyronine 12.5 to 25 mcg once daily; inadequate response despite adequate dosage replacement may indicate nonadherence, poor absorption, excessive elimination, or inactivity of the preparation.

Congenital hypothyroidism

Pediatric dosage

• Infants below 6 months: 
  • Liothyronine (T3): 3.1 to 6.25 mcg/levothyroxine (T4): 12.5 to 25 mcg once daily
• Infants above 6 to 12 months:
  • Liothyronine (T3): 6.25 to 9.35 mcg/levothyroxine (T4): 25 to 37.5 mcg once daily
• Children 1 to 5 years: 
  • Liothyronine (T3): 9.35 to 12.5 mcg/levothyroxine (T4): 37.5 to 50 mcg once daily
• Children 6 to 12 years: 
  • Liothyronine (T3): 12.5 to 18.75 mcg/levothyroxine (T4): 50 to 75 mcg once daily

Adolescents: 

• Typical doses above Liothyronine (T3): 18.75 mcg; levothyroxine (T4): 75 mcg once daily

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Liotrix has severe interactions with the following drugs:
  • Sodium iodide I-131
• Liotrix has serious interactions with no other drugs.
• Liotrix has moderate interactions with the following drugs:
  • Didanosine
  • Insulin degludec
  • Insulin degludec/insulin aspart
  • Insulin inhaled
  • Lanthanum carbonate
  • Levonorgestrel oral/ethinylestradiol/ferrous bisglycinate
  • Metformin
  • Nateglinide
  • Warfarin
• Liotrix has minor interactions with the following drugs:
  • Dexlansoprazole
  • Esomeprazole
  • Furosemide
  • Lansoprazole
  • Omeprazole
  • Pantoprazole
  • Rabeprazole

This information does not contain all possible interactions or adverse effects. Visit the rxlist Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions or concerns.

Contraindications

• An adrenal gland problem that is not controlled by treatment.
• Thyrotoxicosis that is not treated with antithyroid medication; or
• Certain heart conditions. 

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Liotrix?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Liotrix?”

Cautions

• Liotrix should not be used to treat obesity or weight problems.
• You may not be able to use this medicine if you have thyrotoxicosis or an adrenal gland problem that is not controlled by treatment.
• Stop taking liotrix and call your doctor if you have symptoms of thyroid toxicity, such as chest pain, fast or pounding heartbeats, feeling hot or nervous, or sweating more than usual. 
• Follow your doctor's instructions about any restrictions on food or beverages. You may need to avoid certain foods that are high in fiber and can make it harder for your body to absorb this medicine.
• Do not change brands or change to a generic product without first asking your doctor. Different brands of liotrix may not work the same. If you get a prescription refill and your new pills look different, talk with your pharmacist or doctor.

Pregnancy and Lactation

• Tell your doctor if you are pregnant. Follow your doctor's instructions about using this medicine if you are pregnant or you become pregnant. Controlling diabetes is very important during pregnancy, and having high blood sugar may cause complications in both the mother and the baby.
• Lactation
  • Small amounts excreted into breast milk, use caution. Tell your doctor if you are breastfeeding.