Levothroid

DRUG DESCRIPTION

LEVOTHROID® (levothyroxine sodium) Tablets, USP contains synthetic crystalline L-3, 3', 5, 5'-tetraiodothyronine sodium salt [levothyroxine (T4) sodium]. Synthetic T4 is identical to that produced in the human thyroid gland. Levothyroxine (T4) sodium has an empirical formula of C15H10I4N NaO4 x H2O, molecular weight of 798. 86 g/mol (anhydrous), and structural formula as shown:

LEVOTHROID® (levothyroxine sodium) Structural Formula Illustration

Inactive Ingredients: Microcrystalline cellulose, calcium phosphate dibasic, povidone and magnesium stearate. The following are the coloring additives per tablet strength.

Strength (mcg) Color additive(s)
25 FD&C Yellow No.6 Aluminum Lake
50 None
75 FD&C Blue No.2 Aluminum Lake, FD&C Red No.40 Aluminum Lake
88 FD&C Yellow No.6 Aluminum Lake, FD&C Blue No.1 Aluminum Lake, D&C Yellow No.10 Aluminum Lake
100 FD&C Yellow No.6 Aluminum Lake, D&C Yellow No.10 Aluminum Lake
112 D&C Red No.27 Aluminum Lake, D&C Red No.30 Aluminum Lake
125 FD&C Blue No.1 Aluminum Lake, FD&C Red No.40 Aluminum Lake, FD&C Yellow No.6 Aluminum Lake
137 FD&C Blue No.1 Aluminum Lake
150 FD&C Blue No.2 Aluminum Lake
175 FD&C Blue No.1 Aluminum Lake, D&C Red No.30 Aluminum Lake, D&C Red No.27 Aluminum Lake
200 FD&C Red No.40 Aluminum Lake
300 FD&C Yellow No.6 Aluminum Lake, FD&C Blue No.1 Aluminum Lake, D&C Yellow No.10 Aluminum Lake

What are the possible side effects of levothyroxine (Levothroid, Levoxyl, Synthroid, Unithroid)?

Stop using levothyroxine and get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

  • headache;
  • sleep problems (insomnia);
  • nervous or irritable feeling;
  • fever, hot flashes, sweating;
  • changes in your menstrual periods;
  • appetite changes, weight...

Read All Potential Side Effects and See Pictures of Levothroid »

What are the precautions when taking levothyroxine sodium (Levothroid)?

Before taking levothyroxine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: increased thyroid hormones (thyrotoxicosis), decreased adrenal gland function, heart disease (such as coronary artery disease, irregular heartbeat), high blood pressure, diabetes.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Current information shows that this drug may be used during pregnancy....

Read All Potential Precautions of Levothroid »


Levothroid Consumer (continued)

SIDE EFFECTS: Hair loss may occur during the first few months of treatment. This effect is usually temporary as your body adjusts to this medication. If this effect persists or worsens, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious effects of high thyroid hormone levels occur: increased sweating, sensitivity to heat, mental/mood changes (such as nervousness, mood swings), tiredness, diarrhea, shaking (tremor), headache, shortness of breath.

Get medical help right away if any of these rare but serious effects of high thyroid hormone levels occur: chest pain, fast/pounding/irregular heartbeat, swelling hands/ankles/feet, seizures.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking levothyroxine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: increased thyroid hormones (thyrotoxicosis), decreased adrenal gland function, heart disease (such as coronary artery disease, irregular heartbeat), high blood pressure, diabetes.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Current information shows that this drug may be used during pregnancy. Tell your doctor if you are pregnant because your dose may need to be adjusted.

Levothyroxine passes into breast milk but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.


Levothroid Patient Information Including Side Effects

Brand Names: Levothroid, Levoxyl, Synthroid, Unithroid

Generic Name: levothyroxine (Pronunciation: LEE voe thye ROX een)

  • What is levothyroxine (Levothroid)?
  • What are the possible side effects of levothyroxine (Levothroid)?
  • What is the most important information I should know about levothyroxine (Levothroid)?
  • What should I discuss with my healthcare provider before taking levothyroxine (Levothroid)?
  • How should I take levothyroxine (Levothroid)?
  • What happens if I miss a dose (Levothroid)?
  • What happens if I overdose (Levothroid)?
  • What should I avoid while taking levothyroxine (Levothroid)?
  • What other drugs will affect levothyroxine (Levothroid)?
  • Where can I get more information?

What is levothyroxine (Levothroid)?

Levothyroxine is a replacement for a hormone that is normally produced by your thyroid gland to regulate the body's energy and metabolism. Levothyroxine is given when the thyroid does not produce enough of this hormone on its own.

Levothyroxine treats hypothyroidism (low thyroid hormone). Levothyroxine is also used to treat or prevent goiter (enlarged thyroid gland), which can be caused by hormone imbalances, radiation treatment, surgery, or cancer.

Levothyroxine should not be used to treat obesity or weight problems.

Levothyroxine may also be used for other purposes not listed in this medication guide.

What are the possible side effects of levothyroxine (Levothroid)?

Stop using levothyroxine and get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

  • headache;
  • sleep problems (insomnia);
  • nervous or irritable feeling;
  • fever, hot flashes, sweating;
  • changes in your menstrual periods;
  • appetite changes, weight changes;

Less serious side effects may include mild hair loss.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about levothyroxine (Levothroid)?

Since thyroid hormone occurs naturally in the body, almost anyone can take levothyroxine. You should not use this medication if you have had a heart attack, a thyroid disorder called thyrotoxicosis, or an adrenal gland problem that is not controlled by treatment.

Before taking this medication, tell your doctor if you have heart disease, coronary artery disease, anemia (lack of red blood cells), diabetes, problems with your pituitary or adrenal glands, or a history of blood clots.

If you use insulin or take diabetes medicine by mouth, ask your doctor if your dose needs to be changed when you start using levothyroxine.

Different brands of levothyroxine may not work the same. If you get a prescription refill and your new pills look different, talk with your pharmacist or doctor.

It may take several weeks before your body starts to respond to this medication. Do not stop taking this medication suddenly. Even if you feel well, you may still need to take this medicine every day for the rest of your life to replace the thyroid hormone your body cannot produce.

There are many other medicines that can affect levothyroxine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Related Drug Centers
  • Levoxyl
  • Unithroid
  • Synthroid
  • Levothroid


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