Synthroid

(levothyroxine)

In this factsheet:

• How does Synthroid work? What will it do for me?
• How should I use Synthroid?
• What form(s) does Synthroid come in?
• Who should NOT take Synthroid?
• What side effects are possible with Synthroid?
• Are there any other precautions or warnings for Synthroid?
• What other drugs could interact with Synthroid?

DIN (Drug Identification Number)

How does Synthroid work? What will it do for me?

Levothyroxine is a thyroid hormone supplement used to treat people who do not produce enough thyroid hormone on their own. Levothyroxine helps to reduce the symptoms of low thyroid hormone such as weight gain, sensitivity to cold, lack of energy, and dry skin. It may take several weeks for this medication to have a noticeable effect on your condition.

Your doctor may have suggested this medication for conditions other than the ones listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

How should I use Synthroid?

You should take this medication once a day, at the same time every day to ensure a consistent effect. The dose of levothyroxine depends on how much of the hormone is needed to bring blood levels back to the normal range. This is determined by blood tests that are done in a laboratory. The starting dose will depend on the general physical condition of the person taking the medication and the severity and duration of time that symptoms of low thyroid hormone levels have been present.

Signs that you may be getting too much thyroid hormone may include chest pain, increased heart rate, palpitations, excessive sweating, heat intolerance, and nervousness. If you think your dose of thyroid hormone may be too high, consult your doctor as soon as possible.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones given here, do not change the way that you are taking the medication without consulting your doctor.

It is important that this medication be taken exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

What form(s) does Synthroid come in?

25 µg
Each orange, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 25 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, FD&C Yellow No. 6, lactose, magnesium stearate, povidone and talc.

50 µg
Each white, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 50 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, lactose, magnesium stearate, povidone and talc.

75 µg
Each violet, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 75 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, FD&C Blue No. 2, FD&C Red No. 40, lactose, magnesium stearate, povidone and talc.

88 µg
Each olive, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 88 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, D&C Yellow No. 10, FD&C Blue No. 1, FD&C Yellow No. 6, lactose, magnesium stearate, povidone and talc.

100 µg
Each yellow, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 100 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, D&C Yellow No. 10, FD&C Yellow No. 6, lactose, magnesium stearate, povidone and talc.

112 µg
Each rose, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 112 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, D&C Red No. 27 & 30, lactose, magnesium stearate, povidone and talc.

125 µg
Each brown, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 125 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, FD&C Blue No. 1, FD&C Red No. 40, FD&C Yellow No. 6, lactose, magnesium stearate, povidone and talc.

137µg
Each dark blue, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 137 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, FD&C Blue No. 1, lactose, magnesium stearate, povidone and talc.

150 µg
Each blue, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 150 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, FD&C Blue No. 2, lactose, magnesium stearate, povidone and talc.

175 µg
Each lilac, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 175 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, D&C Red No. 27 & 30, FD&C Blue No. 1, lactose, magnesium stearate, povidone and talc.

200 µg
Each pink, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 200 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, FD&C Red No. 40, lactose, magnesium stearate, povidone and talc.

300 µg
Each green, round, colour-coded, scored tablet, debossed with "FLINT" and potency contains levothyroxine sodium 300 µg. Nonmedicinal ingredients: acacia, confectioner's sugar, D&C Yellow No. 10, FD&C Blue No. 1, FD&C Yellow No. 6, lactose, magnesium stearate, povidone and talc.

Some medications may have other generic brands available. Always ask your doctor or pharmacist about the safety of switching between brands of the same medication.

Who should NOT take Synthroid?

Levothyroxine should not be taken by anyone who:

• is allergic to levothyroxine or to any of the ingredients of the medication
• has acute thyrotoxicosis (too much thyroid hormone in their system)
• is having a heart attack
• has uncorrected adrenal insufficiency

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