Synthroid (Levothyroxine) 100mcg (0.1mg)

Synthroid general information

What is Synthroid used for?

Synthroid tablets 100mcg are used to treat hypothyroidism or underactive thyroid, a condition in which the thyroid gland does not make enough thyroid hormone (thyroxine) needed to regulate your body’s growth and metabolism. Hypothyroidism can be idiopathic (of unknown cause) or congenital as in the case of the autoimmune disease Hashimoto's thyroiditis, where the thyroid gland is destroyed by the immune system; it can also be the result of thyroid surgery. Synthroid tablets 100mcg are also used to treat thyroid goitre, which is an enlarged thyroid gland caused by extreme growth of thyroid tissue to compensate for lack of thyroid hormone; also to treat thyroid cancer. Synthroid tablets 100mcg are a replacement hormone to relieve the symptoms of hypothyroidism, including, tiredness, muscle weakness, cramps, feeling the cold, a slow heart rate, dry and flaky skin, hair loss, a deep husky voice and weight gain.

How does Synthroid work?

Synthroid tablets 100mcg contain levothyroxine sodium, a synthetic thyroid hormone that is identical to the naturally occurring thyroid hormone thyroxine or T4, produced by the thyroid gland. Levothyroxine is converted to the more active form of thyroid hormone (T3), which interacts with a specific receptor inside cells to stimulate proteins needed to manage and regulate a variety of processes including how the body regulates temperature, metabolises nutrients and controls growth and development. Thyroxine regulates the production of another hormone called thyroid stimulating hormone (TSH) which in turn controls how much thyroxine is produced. Synthroid tablets 100mcg regulate TSH production in the same way and therefore substitutes for a lack of endogenous thyroxine produced by the thyroid gland.

What does Synthroid contain?

Synthroid tablets 100mcg contain the active ingredient levothyroxine, which replaces the lack of endogenous thyroxine (produced by the thyroid gland) to regulate normal growth and metabolism. They also contain acacia, confectioner's sugar, lactose, magnesium stearate, povidone, talc and colour additives (D&C Yellow No. 10 and FD&C Yellow No. 6).

What doses of Synthroid are available?

Synthroid tablets are available in the following doses:

• Synthroid tablets 100mcg (0.1mg)
• Synthroid tablets 50mcg (0.05mg)
• Synthroid tablets 25mcg (0.025mg)

Treating underactive thyroid (hypothyroidism) with Synthroid

Synthroid tablets 100mcg contain levothyroxine, a synthetic thyroid hormone that is identical to the naturally occurring thyroid hormone thyroxine or T4 and substitutes for the lack of thyroid hormone in hypothyroidism (underactive thyroid gland) to regulate normal growth and metabolism. Synthroid tablets 100mcg are used to treat the symptoms of hypothyroidism, including, tiredness, muscle weakness, cramps, feeling the cold, a slow heart rate, dry and flaky skin, hair loss, a deep husky voice and weight gain.

What are the side effects of Synthroid?

The most commonly reported side effects when taking Synthroid tablets 100mcg are usually related to the dose taken that may be too high and may need adjusting. These include: headache, sleep problems (insomnia), feeling nervous or irritable sweating, flushing, appetite changes, weight loss, muscle weakness/cramps, tremors.

When should Synthroid not be used?

You should not use Synthroid tablets 100mcg if you:

• are allergic to levothyroxine or any of the ingredients in Synthroid tablets
• are pregnant or planning to become pregnant, without discussion with your doctor
• have had a heart attack
• have a thyroid disorder called thyrotoxicosis, or an uncontrolled adrenal gland problem
• are a diabetic taking anti-diabetics or insulin, without discussion with your doctor, as Synthroid may affect your glucose tolerance
• are taking other medications that may interact with Synthroid, such as anticonvulsants like phenytoin and carbamazepin, cardiac glycosides like digoxin for heart failure, cholesterol-lowing drugs containing cholestyramine and some statins, tricyclic antidepressants antidepressants, anticoagulants, androgens and anabolic steroids, antacids for heartburn and indigestion, sucralfate for ulcers, anticancer drugs like tamoxifen, amiodarone for arrhythmia, oral contraceptives

What medications interact with Synthroid?

Several medications interact with Levothyroxine and should either not be taken while you are taking product name or only after discussion and instruction from your doctor:

• Drugs that affect Levothyroxine: the anticonvulsants phenytoin and carbamazepine, cholesterol-lowing drugs containing cholestyramine and some statins, androgens and anabolic steroids, antacids for heartburn and indigestion, sucralfate for ulcers, anticancer drugs like tamoxifen, amiodarone for arrhythmia, oral contraceptives
• Drugs that are affected by Levothyroxine: anticoagulants , the anticonvulsant phenytoin , cardiac glycosides like digoxin for heart failure, tricyclic antidepressants

How should Synthroid be taken?

You should take your Synthroid tablets 100mcg swallowed whole with a glass of water, once daily on an empty stomach, at the same time each day, preferably 30 minutes before eating breakfast. The dose you take depends on your condition, how well you respond and your doctor’s recommendation. Synthroid tablets 100mcg are a long-term treatment and you should continue to take your Synthroid tablets 100mcg regularly for as long as recommended by your doctor, which may be for the rest of your life.

How long should you take Synthroid?

Synthroid tablets 100mcg are a long-term treatment and you should continue to take your Synthroid tablets 100mcg regularly for as long as recommended by your doctor, which may be for the rest of your life.

Missed dose of Synthroid

If you miss a dose of Synthroid tablets 100mcg take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose. Do not take a double dose.

How should Synthroid be stored?

You should store your Synthroid tablets 100mcg in a cool dry place below 25°C and protect from light.