Levo-Thyroxine (Synthetic)

Description

Levo-Thyroxine (Synthetic) is similar to the hormone produced by the thyroid gland. It is primarily used to treat Hypothyroidism, a condition where the thyroid gland does not produce sufficient quantities of hormones. It is also used to treat certain other disorders associated with the thyroid gland.

Side effects

Major & minor side effects for Levo-Thyroxine (Synthetic)

  • Shaking and trembling of arms and feet
  • Headache
  • Nausea and Vomiting
  • Diarrhea
  • Abdominal cramps
  • Nervousness and irritability
  • Sleeplessnes
  • Excessive sweating
  • Fever
  • Changes in menstrual cycle
  • Temporary hair loss
  • Chest pain and discomfort
  • Rapid or irregular heartbeat
  • Thyrotoxic crisis

Uses of Levo-Thyroxine (Synthetic)

What is it prescribed for?

  • Hypothyroidism
  • Thyroid cancer
  • Myxedema coma
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Concerns

Commonly asked questions

  • Onset of action
    The effect of this medicine can be observed within 3-5 days of oral administration. Upon intravenous injection, the effect can be observed within 6-8 hours.
  • Duration of effect
    The time duration for which this medicine remains effective in the body is subject to vary based on the thyroid hormone levels.
  • Safe with alcohol?
    Interaction with alcohol is unknown. It is advisable to consult your doctor before consumption.
  • Is it habit forming?
    No habit forming tendencies were reported.
  • Usage in pregnancy?
    This medicine is safe for use during pregnancy. Consult your doctor before taking this medicine.
  • Usage while breast-feeding?
    This medicine is safe for use while breastfeeding. Consult your doctor before taking this medicine.

Allergy

This medicine is not recommended for use if you have a known allergy to levothyroxine, thyroid hormone, or any other ingredients present with it.

Thyrotoxicosis

This medicine is not recommended for use if you have an excess of thyroid hormone in the body due to overactive glands or hyperthyroidism.

Adrenal insufficiency

This medicine is not recommended for use in patients with an untreated condition where the adrenal glands do not produce steroid hormones in adequate quantities (adrenal insufficiency). Therapy with this medicine in such patients could lead to worsening of the condition of the patient.

Acute myocardial infarction

This medicine is not recommended for use if you have recently had an episode of a heart attack.
Warnings for special population

Pregnancy

This medicine is safe for use during pregnancy. Consult your doctor before taking this medicine.

Breast-feeding

This medicine is safe for use while breastfeeding. Consult your doctor before taking this medicine.
General warnings

Other medicines

Report the use of all medicines including dietary supplements and herbal preparations to the doctor before starting treatment with Levo-Thyroxine (Synthetic) since the likelihood of interactions is significantly high.

Other diseases

Report the incidence of all your previous and active medical conditions to the doctor before starting treatment with this medicine. Your doctor may make appropriate adjustments in the dose and the duration of therapy based on your clinical condition.

Thyroid nodules

This medicine should be used with extreme caution in patients with thyroid nodules. Its use is contraindicated if the serum TSH level is already suppressed.

Use in postmenopausal women

This medicine is not recommended for use in postmenopausal women with osteoporosis, heart disease, or any other systemic illness. Long-term use of this medicine may cause a decrease in bone mineral density, which may increase the risk of fractures.

Treatment of obesity

This medicine should not be used for the treatment of obesity, especially in patients with normal thyroid hormone levels.

Treatment of infertility

This medicine should not be used for the treatment of male/female infertility unless associated with low thyroid hormone levels.

Dose adjsutments

Appropriate dose adjustments should be done based on the patient's disease profile, use of other medicines, food habits, and other parameters. Underdosing or overdosing may lead to severe side effects.

Change of brands

It is advised to consult a doctor or a trained healthcare professional before switching from one brand of this medicine to another. Use of different formulations may cause undesired side effects.

Use in elderly

This medicine should be used with caution in the elderly population since the risk of side effects are significantly high.

Missed Dose

Take the missed dose as soon as you remember it. If it is almost the time for the next scheduled dose, then the missed dose can be skipped. Do not double your dose to make up for the missed one.

Overdose

Contact your doctor immediately if an overdose with this medicine is suspected. Symptoms may include a headache, shaking and trembling of hands and feet, nervousness, irritability, fast and pounding heartbeats, etc.
All drugs interact differently for person to person. You should check all the possible interactions with your doctor before starting any medicine.
Interaction with Alcohol

Description

Interaction with alcohol is unknown. It is advisable to consult your doctor before consumption.

Instructions

Interaction with alcohol is unknown. It is advisable to consult your doctor before consumption.
Interaction with Medicine

Carbamazepine

Phenytoin

Warfarin

Ethinyl Estradiol

Rifampicin

Epinephrine

Phenobarbital

Insulin and other anti diabetic medicines

Ketamine

Testosterone

Amphetamine

Antacids containing calcium/magnesium/aluminum

Disease interactions

Cardiovascular disease

This medicine should be used with caution in patients having a disease of the heart and the blood vessels. Treatment should be initiated at the lowest possible dose with frequent monitoring of cardiovascular functions. If the symptoms of the heart disease worsen, then appropriate dose reductions should be done on priority.

Diabetes

This medicine should be used with caution in patients having diabetes or any other endocrine disorder due to the increased risk of worsening of the condition of the patient. Appropriate dose adjustments and clinical monitoring are advised during treatment with this medicine. The dose of insulin or other anti-diabetic medicines should be adjusted appropriately both during treatment with Levo-Thyroxine (Synthetic) and while discontinuing therapy with Levo-Thyroxine (Synthetic).
Food interactions
Food items containing calcium may reduce the effects of this medicine if both are taken together. There should be a minimum time gap of 4 hours between the consumption of these food items and Levo-Thyroxine (Synthetic). It is advised that you discuss your food habits and diet with the doctor before starting treatment with this medicine.
Medicines or food supplements containing multivitamins with minerals may reduce the effects of this medicine if both are taken together. There should be a minimum time gap of 4 hours between the consumption of multivitamins with minerals and Levo-Thyroxine (Synthetic). It is advised that you inform your doctor about all your current medicines including herbal products before starting treatment with Levo-Thyroxine (Synthetic).
Lab interactions
Information not available.
Take Levo-Thyroxine (Synthetic) exactly as prescribed by the doctor. Do not take in larger or smaller quantities than recommended. Your dose is likely to change over the course of treatment based on the response and tolerance. It may take several weeks before this medicine starts to show its effect. Do not stop the use of this medicine even when the symptoms resolve or improve unless instructed by the doctor.
Miscelleneous

To be taken on an empty stomach

To be taken in morning

Does not cause sleepiness

How it works
This medicine works by replenishing and replacing the hormones produced by the thyroid gland.
Legal Status

Approved

Approved

Approved

Approved

Classification

Category

Thyroid drugs

Schedule

Schedule H

DailyMed - Levothyroxine sodium tablet [Internet]. Dailymed.nlm.nih.gov. 2017 [cited 3 August 2017]. Available from:

https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e95720f2-91c9-a6d0-f7d5-8bcb94d07bbc

Levothyroxine - DrugBank [Internet]. Drugbank.ca. 2017 [cited 3 August 2017]. Available from:

https://www.drugbank.ca/drugs/DB00451

Levothyroxine sodium [Internet]. Pubchem.ncbi.nlm.nih.gov. 2017 [cited 3 August 2017]. Available from:

https://pubchem.ncbi.nlm.nih.gov/compound/23666112#section=Top

Levothyroxine: MedlinePlus Drug Information [Internet]. Medlineplus.gov. 2017 [cited 3 August 2017]. Available from:

https://medlineplus.gov/druginfo/meds/a682461.html

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Information on this page was last updated on 18 Oct 2017

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