What is Synthroid?
Synthroid is a prescription drug used to treat hypothyroidism and goiter (enlarged thyroid gland). Synthroid contains the active ingredient levothyroxine. Synthroid is available as a tablet in the strengths 25mcg, 50mcg, 75mcg, 88mcg, 100mcg, 112mcg, 125mcg, 137mcg, 150mcg, 175mcg, 200mcg, 300mcg.
Synthroid Information
What is Synthroid used for?
The thyroid gland is responsible for producing thyroid hormone which regulates the body’s energy and metabolism. Synthroid is used to treat low thyroid hormone levels in the body when your thyroid gland does not produce enough thyroid hormone.
How to take Synthroid?
Synthroid tablets are taken by mouth usually once daily. Synthroid works best when taken in the morning on an empty stomach 30 to 60 minutes before breakfast. Synthroid should be taken at least 4 hours before or after drugs or food that can interfere with the absorption of Synthroid.
Synthroid dosage can vary greatly due to your thyroid hormone levels, medical condition, age and response to treatment. Synthroid dosage is also often adjusted periodically depending on your thyroid levels after laboratory test results. Always take your Synthroid as instructed by your doctor or pharmacist.
The following foods can cause less Synthroid to be absorbed by the body and should be avoided: Grapefruit juice, cottonseed meal, walnuts, high-fiber foods, soybean flour and infant soy formula.
What is considered a high dose of Synthroid?
Synthroid dosage usually ranges from 25mcg to 200mcg per day. Doses greater than 200mcg per day are rarely required. If there is inadequate response to 300mcg of Synthroid per day this may be due to various factors such as poor compliance, malabsorption, drug interactions or a combination of these factors.
Possible side effects of Synthroid?
Some common side effects of Synthroid are:
- Feeling hot
- Headache
- Leg cramps
- Weight loss
- Diarrhea
- Partial hair loss
- Skin rash
- Trouble sleeping
- Nervousness
Other possible side effects of Synthroid, which can be serious are:
- Changes in your menstrual periods
- Chest pain
- Fast or Irregular heartbeats
- Shortness of breath
- Muscle pain or weakness
- Memory problems
- Feeling depressed, nervous, or irritable
This is not a full list of side effects. Let your doctor know if you experience any of these side effects or any other effects not listed which are persistent.
Possible Drug Interactions with Synthroid?
There are many drugs that can affect the absorption of Synthroid. Always let your doctor or pharmacist know the full list of all the drugs you are taking so they can check for possible interactions with Synthroid.
Some drugs that interact with Synthroid are:
- Calcium carbonate
- Ferrous sulfate
- Sevelemer
- Orlistat
- Colesevelam
- Cholestyramine
- Colestipol
- Kayexalate
- Aluminum hydroxide
- Magnesium hydroxide
- Simethicone
- Salicylates
- Estrogen containing oral contraceptives
- Tamoxifen
- Carbamazepine
- Furosemide
What are the recommended starting doses of Synthroid?
The recommended starting dose of Synthroid (levothyroxine) varies depending on factors like age, weight, underlying health conditions, and the severity of hypothyroidism. For healthy adults under 50, the typical starting dose is 1.6 micrograms per kilogram of body weight per day. Older adults or those with heart disease usually start at a lower dose, around 12.5 to 25 micrograms per day, to avoid stressing the heart. For children, the dose depends on their age and weight. It is important to follow the doctor's specific instructions for dosage and adjustments.
Synthroid Price in Canada
Starting price of Synthroid 25mcg Tablet in Canada
- 90 tabs - $47.48 USD ($0.53 per tabs)
Synthroid FAQs
Is Synthroid the same as levothyroxine?
Yes, Synthroid and levothyroxine are essentially the same medication. The difference is that Synthroid is a brand name, while levothyroxine is the generic form. Although they have the same active ingredient, some people may respond slightly differently to the brand-name version compared to the generic due to variations in the inactive ingredients or how the body absorbs them.
How long does it take for Synthroid to start working?
Synthroid usually starts working within a few days, but it may take 4 to 6 weeks to feel the full effects. The medication gradually restores thyroid hormone levels, and symptoms like fatigue, weight gain, or cold sensitivity may improve as your body adjusts. It’s important to take it consistently as prescribed and follow up with your doctor to monitor your thyroid levels during this period.
Can Synthroid cause weight gain or weight loss?
Synthroid (levothyroxine) is used to treat hypothyroidism (an underactive thyroid). It typically helps people lose weight if they were overweight due to low thyroid hormone levels. However, some people may experience weight gain while taking it, especially if they take too much, which can cause symptoms of hyperthyroidism (an overactive thyroid). In summary, Synthroid can lead to weight loss or weight gain depending on the individual's thyroid levels and dosage.
How often should I have my thyroid levels checked while on Synthroid?
While on Synthroid, it’s generally recommended to have your thyroid levels checked every 6 to 12 months. However, if you’re starting the medication, adjusting your dosage, or experiencing symptoms of thyroid imbalance, your healthcare provider may suggest more frequent testing, such as every 4 to 6 weeks initially. Regular monitoring helps ensure that your thyroid hormone levels are within the target range and that the dosage remains appropriate for your needs. Always follow your doctor's specific recommendations regarding testing frequency.
Can I take Synthroid before a thyroid test?
Generally healthcare providers may advise you to take it after the blood sample is taken to ensure accurate results. It's important to follow your doctor's specific instructions regarding when to take your medication in relation to your thyroid test. Always consult your healthcare provider if you have any concerns or questions about the timing.
Is Synthroid safe during pregnancy?
Yes, Synthroid is generally considered safe to use during pregnancy. It is important for women with hypothyroidism to maintain proper thyroid hormone levels for the health of both the mother and the developing baby. Uncontrolled hypothyroidism during pregnancy can lead to complications. Pregnant women taking Synthroid may require dosage adjustments, so regular monitoring of thyroid levels is essential. Always consult your healthcare provider for personalized advice and to ensure the dosage is appropriate during pregnancy.