Liothyronine (Oral)

As a thyroid hormone supplement, liothyronine treats complications resulting from low thyroid levels in both children and adults.


Thyroid hormone is a substance that is naturally made by the thyroid gland. As such, liothyronine is used to supplement or substitute the natural hormone when its amount drops to unhealthy levels. The medication can treat hypothyroidism or underactive thyroid'a condition that may result from an injured thyroid gland due to the use of certain drugs or exposure to radiation.

As an adult, you need your thyroid gland working well and producing enough thyroid hormone to stay healthy. Children need adequate amounts of the hormone to grow, develop, and learn without unnecessary complications. A significant deficit of the thyroid hormone may require treatment with liothyronine, usually once every day as directed by your doctor.

Available under the brand name Cytomel, liothyronine may also treat goiter'a condition characterized by enlarged thyroid glands. Healthcare givers may recommend the medication to patients with thyroid cancer and particular types of thyroid disease. You should not use the medicine without a doctor's prescription.

Conditions Treated

Type Of Medicine

  • Thyroid hormone supplement

Side Effects

Treatment with liothyronine may cause undesired outcomes that vary in nature and severity from patient to patient. It remains critical that you seek your caregiver's advice about the management of all potential side effects of this medication. Overdosing on the drug may cause severe symptoms that warrant immediate emergency treatment. Such ill-effects include pain in the arm, back, or jaw; appetite fluctuations; lightheadedness; excessive tiredness; or even fainting.

You also need emergency medical care if the improper use of liothyronine causes severe side effects such as leg cramps, sweating, shortness of breath, or vomiting. Likewise, be alarmed if the treatment causes you to lose or add weight, your hands to shake, or your bowel movements to increase. Other reasons for concern include difficulty breathing or sleeping; dilated blood vessels of the neck; nausea; swollen body parts, including lower legs, fingers, or face; increased sensitivity to warmer temperatures; and confusion. Chest pain is a severe liothyronine side effect, and so is a faster, slower, or otherwise unusual heartbeat or pulse.


Doctors treat each hypothyroidism (or any other thyroid gland complication) case on its merit, meaning that the right dosing of liothyronine usually differs from patient to patient. In addition to your particular health condition, your caregiver will consider your age, medical exam results, and symptoms' improvement to determine proper dosage.

The liothyronine regimen is available in the form of a tablet that you should take by mouth, typically once every day. Follow your doctor's prescription requirements, including the daily amount of the medication you should use and the frequency of intake. Always review and understand the directions for using the drug as provided on the product label.

Most likely, your doctor will initially recommend to you a low dose of liothyronine. Wait for the caregiver to adjust the dosing upward because only he or she can decide the perfect timing for the change over the course of your treatment. Depending on how you respond to the medication, the dosage may increase once at intervals of 1 to 2 weeks. When it is time to enhance your dosage, it is also imperative that the healthcare practitioner works out the right increment, such as by 5, 10, or 25 micrograms.

Most hypothyroidism patients have to continue taking their liothyronine medication for the rest of their life because they have a persistent low thyroid hormone problem. You may also have to do the same, even if you do not feel sick. Only your doctor can authoritatively determine when it is safe for you to stop taking the drug.

Typically, doctors recommend an initial dose of 25 micrograms once every day to adults with mild hypothyroidism. The daily dosage for this condition may eventually go up to a maximum of 75 micrograms.

When it comes to treating myxedema in adults, a starting per-day dose of 5 micrograms may suffice. The daily dosage may change at appropriate intervals by 5-10 micrograms before reaching 25 micrograms per day, from which point it may increase gradually in more significant amounts to a maximum of 100 micrograms every day.

To treat congenital hypothyroidism in children, an initial dose of 5 micrograms once per day will do. The dosage is subject to gradual increase. As for 1-year-olds and younger, 20 micrograms of liothyronine once per day may work, while kids in the 1-3 years age bracket may need 50 micrograms once every day.

If your child has mild hypothyroidism, congenital hypothyroidism, or myxedema, you should take them to a doctor and obtain a proper prescription. There may be no medical evidence of differences in the effects of liothyronine in minors, but you want to consult extensively before giving the medication to your child.

After you have skipped any liothyronine dose, make up for it at your earliest opportunity. Nonetheless, if it is nearly the time for your next usual dose, just take it and forgo the missed one. Avoid double dosing no matter your circumstances.

Major Drug Interactions

While you are taking liothyronine to treat hypothyroidism or any other thyroid gland-related complication, you need to avoid using other drugs that may interfere with your treatment or bring more harm. Your doctor should take note of each other medication you are currently using. If the caregiver identifies potential clinical interactions between the regimens, they should consider either not prescribing liothyronine to you or altering the dosage of one or both of the medicines.

Some drugs may impede your treatment by slowing the absorption of liothyronine in your system. If such medical remedies are necessary for your wellness, you may have to take them at least four hours before using the low thyroid hormone medication. These medicines include medication that contains aluminum or magnesium. Sodium polystyrene sulfonate, antacids, acid-binding resins (including cholestyramine and colesevelam), and calcium supplements may also have clinical interactions with liothyronine.

Before starting your liothyronine treatment, notify your doctor if you are already using warfarin or other blood thinners; oral diabetes medication; amitriptyline or other tricyclic depression medication; or oral birth control drugs that contain estrogen. Proper use (or not using at all) of kelp or midodrine together with liothyronine may help avoid potentially significant medicinal interactions.

Do not forget to discuss with your doctor the safe use of food, drinks, and other substances along with liothyronine. While at it, seek medical advice about the consumption of tobacco products, nutritional supplements, herbal solutions, and other prescription and over-the-counter drugs.

Warnings And Precautions

  • Obese patients with normal thyroid function should not take liothyronine. For purposes of weight loss, an individual would have to take liothyronine in amounts that are larger than those required to address their thyroid hormone deficiency every day. Never use large doses of liothyronine to avoid incurring severe or potentially fatal toxicity, mainly if you are also taking any amphetamine.
  • If applicable, make sure your doctor considers your allergy to liothyronine or any substance or drug that contains it. Report any existing adverse reactions to thyroid hormone or levothyroxine.
  • It is likely that your caregiver will not prescribe liothyronine to you if you have adrenal insufficiency or thyrotoxicosis. It is also critical that you inform your caregiver if you have or have had diabetes; heart complications (such as hypertension, hardening of the blood vessels, heart attack, a fast or slow heartbeat); or chest pain.
  • Other health conditions that are worth mentioning to your doctor before you begin your liothyronine treatment include kidney malfunction, other complications of the adrenal gland, underactive pituitary gland, blood clotting defects, myxedema, and underactive ovary or testis.
  • Men and women with infertility cannot treat their condition with liothyronine unless their problem is the result of low thyroid hormone levels.
  • If you have diabetes and are using liothyronine, it is imperative that you avoid any negative impact on your blood sugar levels. Therefore, you should take regular blood or urine tests in line with your doctor's directions. Seek immediate medical help once your blood glucose levels change.
  • Some patients experience short-term hair loss a couple of months into their hypothyroidism medication.
  • Do not hesitate to seek emergency care if, while taking liothyronine, you experience a racing or otherwise irregular heartbeat, chest pain, excessive sweating, abnormal sensitivity to heat, or anxiety.
  • Your doctor needs to monitor the progress of your treatment, so you have to keep visiting them. Keep in mind that a change of dose as directed by your caregiver may be necessary over the course of treatment and emerging adverse body reactions may require medical intervention from time to time. Lab tests play a vital role in the assessment of your response to liothyronine.
  • See your doctor if your hypothyroidism symptoms fail to improve within a reasonable time after you have started using liothyronine. However, the first signs of recovery may emerge in a few days or even several weeks.
  • Your surgeon or dentist may want to know if you are using liothyronine before they can perform a major operation or invasive procedure on you.
  • If you are taking liothyronine while breastfeeding, consult your doctor about any risks the medication may pose to your child.


The right storage conditions for liothyronine include:

  • In a closed prescription container or box
  • Away from heat
  • Room temperature
  • Moisture-free
  • Away from direct light
  • Out of the reach of minors

Additionally, do not freeze the tablets or keep them for longer than you have to. Consult your doctor or pharmacist about proper ways to get rid of any excess supplies of liothyronine.


The use of liothyronine according to the instructions your doctor has provided can help treat hypothyroidism and a host of other complications related to low thyroid hormone levels. To keep the symptoms of this disorder in check, you may have to use the drug for the remainder of your life. Successful treatment with the medication helps adults to stay healthy, and children to achieve their growth and cognitive potential.

As you use liothyronine, watch out for possible side effects, including intolerance to hot temperatures, chest pain, and irregular heartbeats/pulses. Seek emergency medical care if such symptoms affect you. Equally important, inform your doctor of any other drugs you are on to help them prescribe a thyroid hormone dose that is safe to use along with the regimens.

Be straightforward with your doctor regarding any other health conditions you have or have ever had. The presence of certain disorders or diseases, such as thyrotoxicosis, may rule out the possibility of the patient using liothyronine safely. Dosage adjustment may be necessary in other cases.