Medically reviewed by Drugs.com. Last updated on Dec 29, 2021.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Thyroid Supplement
Uses for Thyrolar
Liotrix is used to treat hypothyroidism, a condition where the thyroid gland does not produce enough thyroid hormone. It is also used to help decrease the size of enlarged thyroid glands (known as goiter) and to treat thyroid cancer .
Liotrix is also used in some medical tests to help diagnose problems with the thyroid gland .
This medicine is available only with your doctor's prescription .
Before using Thyrolar
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies performed to date have not demonstrated pediatrics-specific problems that would limit the usefulness of liotrix in children .
Appropriate studies performed to date have not demonstrated geriatrics-specific problems that would limit the usefulness of liotrix in the elderly. However, elderly patients are more likely to have age-related heart and blood vessel problems, which may require caution in patients receiving liotrix .
Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.Liothyronine
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Aluminum Carbonate, Basic
- Aluminum Hydroxide
- Aluminum Phosphate
- Calcium Acetate
- Calcium Carbonate
- Calcium Citrate
- Conjugated Estrogens
- Conjugated Estrogens Synthetic A
- Conjugated Estrogens Synthetic B
- Dihydroxyaluminum Aminoacetate
- Dihydroxyaluminum Sodium Carbonate
- Esterified Estrogens
- Ethinyl Estradiol
- Lanthanum Carbonate
- Magnesium Carbonate
- Magnesium Hydroxide
- Magnesium Oxide
- Magnesium Trisilicate
- Polyestradiol Phosphate
- Sodium Polystyrene Sulfonate
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.
- Enteral Nutrition
Other medical problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Adrenal insufficiency (untreated) or
- Thyrotoxicosis (untreated, overactive thyroid)—This medicine should NOT be used in patients with any of these conditions .
- Clotting disorder or
- Diabetes or
- Heart disease (history of) or
- Other adrenal gland problems—Use with caution. Dosage adjustment may be needed .
Proper use of Thyrolar
This section provides information on the proper use of a number of products that contain liotrix. It may not be specific to Thyrolar. Please read with care.
This medicine usually needs to be taken for the rest of your life. Do not stop taking this medicine or change your doses without first checking with your doctor. It may take several weeks before you start to notice an improvement in your symptoms .
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablet):
- For the treatment of hypothyroidism:
- Adults—At first, one tablet of liotrix (Thyrolar-1/2) containing 6.25 microgram (mcg) of liothyronine and 25 mcg of levothyroxine once a day. Your doctor may increase your dose by one tablet of liotrix (Thyrolar-1/4) containing 3.1 mcg of liothyronine and 12.5 mcg of levothyroxine every 2 to 3 weeks. However, the dose is usually not more than one tablet of liotrix (Thyrolar-3) containing 37.5 mcg of liothyronine and 150 mcg of levothyroxine once a day.
- Children—Follow dosing for the treatment of congenital hypothyroidism .
- For the treatment of congenital hypothyroidism:
- Children 0 to 6 months of age—At first, 3.1 mcg of liothyronine and 12.5 mcg of levothyroxine once a day. Doses may be increased as needed. However, the dose is usually not more than 6.25 mcg of liothyronine and 25 mcg of levothyroxine once a day.
- Children 6 to 12 months of age—At first, 6.25 mcg of liothyronine and 25 mcg of levothyroxine once a day. Doses may be increased as needed. However, the dose is usually not more than 9.35 mcg of liothyronine and 37.5 mcg of levothyroxine once a day.
- Children 1 to 5 years of age—At first, 9.35 mcg of liothyronine and 37.5 mcg of levothyroxine once a day. Doses may be increased as needed. However, the dose is usually not more than 12.5 mcg of liothyronine and 50 mcg of levothyroxine once a day.
- Children 6 to 12 years of age—At first, 12.5 mcg of liothyronine and 50 mcg of levothyroxine once a day. Doses may be increased as needed. However, the dose is usually not more than 18.75 mcg of liothyronine and 75 mcg of levothyroxine once a day.
- Children over 12 years of age—The usual dose is 18.75 mcg of liothyronine and 75 mcg of levothyroxine once a day. Doses may be increased as needed .
- For the treatment of hypothyroidism:
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store in the refrigerator. Do not freeze.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Precautions while using Thyrolar
It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. Blood and urine tests will be needed to check for unwanted effects .
Liotrix should not be used for the treatment of obesity or for the purpose of losing weight. This medicine is ineffective for weight reduction and when taken in larger amount, it may cause more serious medical conditions .
Hypothyroidism can sometimes cause infertility in men and women. Liotrix should not be used for the treatment of infertility unless it is caused by hypothyroidism .
Call your doctor right away if you start to have chest pain, fast or irregular heartbeat, excessive sweating, heat intolerance, nervousness, or any other unusual medical condition .
For patients with diabetes, it is very important that you keep track of your blood or urine sugar levels as instructed by your doctor. Check with your doctor immediately if you notice any changes in your sugar levels .
A temporary loss of hair may occur during the first few months of liotrix therapy. Ask your doctor about this if you have any concerns .
Thyrolar side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Incidence not determined
- Chest pain
- depressed mood
- difficulty in moving
- dryness of the eye
- dry skin and hair
- fast, irregular, pounding, or racing heartbeat or pulse
- fear, nervousness
- feeling cold
- feeling sad or empty
- hives or welts
- hoarseness or husky voice
- increased sweating
- increased weight
- increase in blood pressure
- itching skin
- joint pain, stiffness or swelling
- lack of appetite
- lack or loss of strength
- loss of interest or pleasure
- muscle aching or cramping
- muscle pain or stiffness
- redness of skin
- shakiness in legs, arms, hands, feet
- shortness of breath
- skin rash
- slowed heartbeat
- swelling of eyelids, face, lips, hands, or feet
- swollen joints
- tightness in chest
- trembling or shaking of hands or feet
- trouble concentrating
- troubled breathing or swallowing
- trouble sleeping
- unable to sleep
- unusual tiredness or weakness
- weight gain
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Incidence not determined
- Hair loss, thinning of hair
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about Thyrolar (liotrix)
- Side effects
- Drug interactions
- Dosage information
- During pregnancy or Breastfeeding
- Drug class: thyroid drugs
Related treatment guides
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