Liothyronine

Liothyronine is part of the drug class:

• Thyroid hormones

Take liothyronine exactly as prescribed.

Oral:

• Liothyronine comes in tablet form and is taken once daily, with or without food.
• Take this medication with water.
• If it upsets your stomach, try taking liothyronine with food. 
• If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take two doses of liothyronine at the same time.

Injectable:

• This medication is available in an injectable form to be given directly into a vein (IV) by a healthcare professional.

If you take too much this medication, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

If this medication is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

Since thyroid hormone occurs naturally in the body, almost anyone can take liothyronine. However, you may not be able to use this medication if you have a thyroid disorder called thyrotoxicosis, or an adrenal gland problem that is not controlled by treatment.

Before taking liothyronine, tell your doctor if you have heart disease, angina (chest pain), coronary artery disease, congestive heart failure, diabetes, or problems with your pituitary or adrenal glands.

Tell your doctor if you are pregnant or breast-feeding.

To be sure this medication is helping your condition, your blood may need to be tested often. Visit your doctor regularly.

Keep using this medicine as directed, even if you feel well. You may need to take thyroid medication for the rest of your life.

Call your doctor if you notice any signs of thyroid toxicity, such as chest pain, fast or pounding heartbeats, feeling hot or nervous, or sweating more than usual.

Since thyroid hormone occurs naturally in the body, almost anyone can take liothyronine. However, you may not be able to use this medication if you have a thyroid disorder called thyrotoxicosis, or an adrenal gland problem that is not controlled by treatment.

To make sure you can safely take liothyronine, tell your doctor if you have any of these other conditions:

• heart disease, angina (chest pain);

• coronary artery disease;

• congestive heart failure;

• any type of diabetes; or

• problems with your pituitary or adrenal gland.

FDA pregnancy category A. Liothyronine is not expected to harm an unborn baby. However, tell your doctor if you become pregnant, since your dose needs may be different during pregnancy.

Small amounts of liothyronine can pass into breast milk, but this is not expected to harm a nursing baby. However, do not use this medication without telling your doctor if you are breast-feeding a baby.

liothyronine usually needs to be taken for the rest of your life. Do not stop taking liothyronine 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 .

Dosing

The dose of liothyronine 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 liothyronine. 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 mild hypothyroidism:
    • Adults—At first, 25 micrograms (mcg) once a day. Doses may be increased by up to 25 mcg every 1 or 2 weeks. However, the dose usually is not more than 75 mcg once a day.
    • Children—Use and dose must be determined by your doctor .
  • For the treatment of myxedema:
    • Adults—At first, 5 mcg once a day. Doses may be increased by 5 to 10 mcg daily every 1 or 2 weeks. When the daily dose of 25 mcg is reached, dosage may be increased by 5 to 25 mcg every 1 or 2 weeks as needed. However, the dose usually is not more than 100 mcg once a day.
    • Children—Use and dose must be determined by your doctor .
  • For the treatment of congenital hypothyroidism:
    • Adults and children over 3 years of age—Use and dose must be determined by your doctor.
    • Children—At first, 5 mcg once a day. Dosage may be increased by 5 mcg every 3 or 4 days as needed.
    • Children 0 to 1 year of age—20 mcg once a day for maintenance.
    • Children 1 to 3 years of age—50 mcg once a day .
  • For the treatment of simple (non-toxic) goiter:
    • Adults—At first, 5 mcg once a day. Doses may be increased by 5 to 10 mcg daily every 1 or 2 weeks. When the daily dose of 25 mcg is reached, dosage may be increased by 12.5 to 25 mcg every 1 or 2 weeks as needed. However, the dose usually is not more than 75 mcg once a day.
    • Children—Use and dose must be determined by your doctor .

Missed Dose

If you miss a dose of liothyronine, 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.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

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.

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 .

Liothyronine should not be used for the treatment of obesity or for the purpose of losing weight. liothyronine 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. Liothyronine 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 liothyronine therapy. Ask your doctor about this if you have any concerns .

Thyroid hormone preparations are generally contraindicated in patients with diagnosed but as yet uncorrected adrenal cortical insufficiency or untreated thyrotoxicosis. Thyroid hormone preparations are also generally contraindicated in patients with hypersensitivity to any of the active or extraneous constituents of these preparations; however, there is no well-documented evidence in the literature of true allergic or idiosyncratic reactions to thyroid hormone.

Concomitant use of Liothyronine sodium injection (T3) and artificial rewarming of patients is contraindicated. (See PRECAUTIONS.)

Drugs with thyroid hormone activity, alone or together with other therapeutic agents, have been used for the treatment of obesity. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction.  Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects.

Congenital hypothyroidism: Oral: 5 mcg/day increase by 5 mcg every 3 to 4 days until the desired response is achieved. Usual maintenance dose: 20 mcg/day for infants, 50 mcg/day for children 1 to 3 years of age, and adult dose for children >3 years.

Vials must be stored under refrigeration at 2°C to 8°C (36°F to 46°F). Store tablets at 15°C to 30°C (59°F to 86°F).

Amiodarone: May diminish the therapeutic effect of Thyroid Products. Monitor therapy

Bile Acid Sequestrants: May decrease the serum concentration of Thyroid Products. Management: Administer oral thyroid products at least 4 h prior to colesevelam, and at least 1 h before or 4-6 h after cholestyramine. Specific recommendations for colestipol are not available. Monitor for decreased concentrations/effects of the thyroid product. Consider therapy modification

Calcium Polystyrene Sulfonate: May decrease the serum concentration of Thyroid Products. Management: To minimize risk of interaction, separate dosing of oral calcium polystyrene sulfonate and thyroid products (eg, levothyroxine) or administer calcium polystyrene sulfonate rectally. Monitor for signs/symptoms of hypothyroidism with concomitant use (oral). Consider therapy modification

Calcium Salts: May diminish the therapeutic effect of Thyroid Products. Management: Separate the doses of the thyroid product and the oral calcium supplement by at least 4 hours. Consider therapy modification

CarBAMazepine: May decrease the serum concentration of Thyroid Products. Monitor therapy

Ciprofloxacin (Systemic): May decrease the serum concentration of Thyroid Products. Monitor therapy

Estrogen Derivatives: May diminish the therapeutic effect of Thyroid Products. Monitor therapy

Fosphenytoin: May decrease the serum concentration of Thyroid Products. Phenytoin may also displace thyroid hormones from protein binding sites. Monitor therapy

Lanthanum: May decrease the serum concentration of Thyroid Products. Management: Administer oral thyroid products at least two hours before or after lanthanum. Consider therapy modification

Phenytoin: May decrease the serum concentration of Thyroid Products. Phenytoin may also displace thyroid hormones from protein binding sites. Monitor therapy

Piracetam: May enhance the adverse/toxic effect of Thyroid Products. Specifically, symptoms including confusion, irritability, and sleep disorder have been described during concomitant use. Monitor therapy

RifAMPin: May decrease the serum concentration of Thyroid Products. Monitor therapy

Ritonavir: May diminish the therapeutic effect of Thyroid Products. Monitor therapy

Selective Serotonin Reuptake Inhibitors: May diminish the therapeutic effect of Thyroid Products. Thyroid product dose requirements may be increased. Monitor therapy

Sodium Iodide I131: Thyroid Products may diminish the therapeutic effect of Sodium Iodide I131. Avoid combination

Sodium Polystyrene Sulfonate: May decrease the serum concentration of Thyroid Products. Management: To minimize risk of interaction, separate dosing of oral sodium polystyrene sulfonate and thyroid products (e.g., levothyroxine) or administer sodium polystyrene sulfonate rectally. Monitor for signs/symptoms of hypothyroidism with concomitant use (oral). Consider therapy modification

Theophylline Derivatives: Thyroid Products may increase the metabolism of Theophylline Derivatives. Exceptions: Dyphylline. Monitor therapy

Tricyclic Antidepressants: Thyroid Products may enhance the arrhythmogenic effect of Tricyclic Antidepressants. Thyroid Products may enhance the stimulatory effect of Tricyclic Antidepressants. Monitor therapy

Vitamin K Antagonists (eg, warfarin): Thyroid Products may enhance the anticoagulant effect of Vitamin K Antagonists. Monitor therapy

Drugs with thyroid hormone activity, alone or together with other therapeutic agents, have been used for the treatment of obesity. In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction. Larger doses may produce serious or even life-threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines, such as those used for their anorectic effects.

75 to 100 mcg orally per day for 7 days

Comments:
-Radioactive iodine uptake is determined before and after administration of the thyroid hormone.
-If thyroid function is under normal control, the radioiodine uptake will drop significantly after treatment.
-Administer cautiously to patients in whom there is a strong suspicion of thyroid gland autonomy, in view of the fact that the exogenous hormone effects will be additive to the endogenous source.

Use: For use as a diagnostic agent in suppression tests to differentiate suspected mild hyperthyroidism or thyroid gland autonomy

Data not available