Tirosint Sol

Generic name: Levothyroxine Capsules
Drug class: Thyroid drugs

Medically reviewed by A Ras MD.

What is Tirosint Sol?

Tirosint Sol is a prescription medicine that contains a hormone called levothyroxine which is normally produced by the thyroid gland. Tirosint Sol is used to replace or give extra levothyroxine in people whose thyroid does not produce enough of this hormone (hypothyroidism); or with surgery and radiodine therapy to manage a type of thyroid cancer called thyroid-dependent well-differentiated thyroid cancer.

Tirosint Sol should not be used to treat people who are recovering from swelling of the thyroid gland (thyroiditis) and whose bodies do not produce enough levothyroxine for a short time.

Description

TIROSINT-SOL (levothyroxine sodium) oral solution contains synthetic L-3,3′,5,5′-tetraiodothyronine sodium salt [levothyroxine (T4) sodium]. Synthetic T4 is chemically identical to that produced in the human thyroid gland. Levothyroxine (T4) sodium has an empirical formula of C 15H 10I 4NNaO 4 ∙ x H 2O (where x = 5), molecular weight of 798.86 g/mol (anhydrous),

Structural Formula

TIROSINT-SOL oral solution is a clear, colorless to slightly yellow solution supplied in a 1 mL white, non-transparent, unit-dose ampule and is available in the following strengths (mcg/mL): 13, 25, 37.5, 44, 50, 62.5, 75, 88, 100, 112, 125, 137, 150, 175, 200.

The inactive ingredients in TIROSINT-SOL are glycerol and water.

Mechanism of Action

Thyroid hormones exert their physiologic actions through control of DNA transcription and protein synthesis. Triiodothyronine (T3) and L-thyroxine (T4) diffuse into the cell nucleus and bind to thyroid receptor proteins attached to DNA. This hormone nuclear receptor complex activates gene transcription and synthesis of messenger RNA and cytoplasmic proteins.

The physiological actions of thyroid hormones are produced predominantly by T3, the majority of which (approximately 80%) is derived from T4 by deiodination in peripheral tissues

What is the most important information I should know about Tirosint Sol?

Do not use Tirosint Sol to treat weight problems or weight loss.

Who should not take Tirosint Sol?

Do not take Tirosint Sol:

if you are allergic to glycerol the inactive ingredient in Tirosint Sol; or
if your adrenal glands are not working well and you have not been treated for this problem.

What should I tell my healthcare provider before taking Tirosint Sol?

Before you take Tirosint Sol, tell your doctor about all of your medical conditions, including if you:

have or have had heart problems
have or have had thyroid nodules
have adrenal or pituitary gland problems
have any food or drug allergies
have low red blood cell count (anemia)
have diabetes
have weak bones (osteoporosis)
have or had a history of blood clotting problems
have recently received radiation therapy with iodine (such as I-131)
are pregnant or plan to become pregnant. Your doctor may need to change your Tirosint Sol dose while you are pregnant.
are breastfeeding. Tirosint Sol can pass into your milk. Talk to your doctor about the best way to feed your baby if you take Tirosint Sol.

Tell your doctor about all the medicines you are taking including prescription and over-the-counter medicines, vitamins and herbal supplements. Tirosint Sol may affect the way other medicines work, and other medicines may affect how Tirosint Sol works so your doctor may have to adjust the amount of medicines you take. You can ask your doctor or pharmacist for a list of medicines that interact with Tirosint Sol.

How should I take Tirosint Sol?

Tirosint Sol is for oral use only. Do not inhale, inject, or place Tirosint Sol in the eyes.
See the detailed Instructions for use that come with Tirosint Sol for information on the right way to take your dose of Tirosint Sol oral solution.
Take Tirosint Sol exactly as your doctor tells you to take it.
Your doctor will tell you how much Tirosint Sol to take each day.
Your doctor may change your dose, if needed.
Take your dose of Tirosint Sol 1 time each day 30 minutes to 1 hour before breakfast on an empty stomach.
Certain medicines can interfere with how Tirosint Sol is absorbed by your body. Take Tirosint Sol:
- at least 4 hours before or after you take medicines that contain calcium carbonate or iron (ferrous sulfate); and
- at least 4 hours before you take medicines that contain bile acid sequestrants or ion exchange resins.

Know the medicines you take. Ask your doctor or pharmacist for a list of these medicines, if you are not sure.

Certain foods including soybean flour, cotton seed meal, walnuts, and dietary fiber can affect your treatment and dose of Tirosint Sol. Talk to your doctor if you eat or drink these foods.
Do not remove Tirosint Sol ampules from the sealed aluminum foil pouch until you are ready to use them.
Use all 5 Tirosint Sol ampules within 15 days after opening the aluminum foil pouch.
Your doctor should do certain blood tests while you are taking Tirosint Sol and may change your daily dose of Tirosint Sol as needed. Keep taking Tirosint Sol unless your doctor tells you to stop or to change your dose.

It may take weeks before you notice your symptoms getting better. Keep using this medicine even if you feel well. If you take too much Tirosint Sol, call your doctor, your Poison Control Center at 1-800-222-1222, or go to the nearest hospital emergency room right away.

What are the possible side effects of Tirosint Sol?

Tirosint Sol may cause serious side effects, including:

heart problems. You may experience an increased heart rate, chest pain and irregular heartbeat. Your risk of developing heart problems may be greater if you are elderly, you have heart problems, or you take too much Tirosint Sol. Your doctor may reduce your dose or stop treatment with Tirosint Sol for a while if you develop heart problems.
worsening diabetic control. If you are diabetic, it may be harder to control your blood sugar levels causing hyperglycemia while taking Tirosint Sol. Check your blood sugar levels closely after starting, changing, or stopping treatment with Tirosint Sol. Your doctor may have to change your diabetes treatment plan.
weak or brittle bones. Your risk of developing weak or brittle bones may be greater if you are post-menopausal or you take too much Tirosint Sol.

The most common side effects of Tirosint Sol include:

fast or irregular heartbeat
chest pain
shortness of breath
leg cramps
headache
nervousness
hives or skin rash
irritability
sleep problems (insomnia)
tremors
muscle weakness
change in appetite
weight loss
vomiting
diarrhea
sweating a lot
heat intolerance
fever
changes in menstrual period

Other side effects may include partial hair loss during the first months of treatment with Tirosint Sol. This usually lasts a short period of time (temporary).

These are not all the possible side effects of Tirosint Sol. Call your doctor for medical advice about side effects. You may report side effects to IBSA Pharma Inc. at 1-800-587-3513 or FDA at 1-800-FDA-1088.

General information about the safe and effective use of Tirosint Sol

Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use Tirosint Sol for a condition for which it was not prescribed. Do not give Tirosint Sol to other people, even if they have the same symptoms as you. It may harm them. You can ask your pharmacist or doctor for information about Tirosint Sol that is written for health professionals.