Levothroid (Levothyroxine Sodium) - Summary

LEVOTHROID SUMMARY

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 sodium is used for the following indications:

Hypothyroidism - As replacement or supplemental therapy in congenital or acquired hypothyroidism of any etiology, except transient hypothyroidism during the recovery phase of subacute thyroiditis. Specific indications include: primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) hypothyroidism and subclinical hypothyroidism. Primary hypothyroidism may result from functional deficiency, primary atrophy, partial or total congenital absence of the thyroid gland, or from the effects of surgery, radiation, or drugs, with or without the presence of goiter.

Pituitary TSH Suppression - In the treatment or prevention of various types of euthyroid goiters (see WARNINGS and PRECAUTIONS), including thyroid nodules (see WARNINGS and PRECAUTIONS), subacute or chronic lymphocytic thyroiditis (Hashimoto's thyroiditis), multinodular goiter (see WARNINGS and PRECAUTIONS) and, as an adjunct to surgery and radioiodine therapy in the management of thyrotropin-dependent well-differentiated thyroid cancer.

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NEWS HIGHLIGHTS

Media Articles Related to Levothroid (Levothyroxine)

levothyroxine sodium, Synthroid, Levoxyl, Levothroid, Unithroid
Source: MedicineNet Pendred Syndrome Specialty [2007.11.16]
Title: levothyroxine sodium, Synthroid, Levoxyl, Levothroid, Unithroid
Category: Medications
Created: 12/31/1997
Last Editorial Review: 11/16/2007

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Published Studies Related to Levothroid (Levothyroxine)

Chromosome translocation frequency after radioiodine thyroid remnant ablation: a comparison between recombinant human thyrotropin stimulation and prolonged levothyroxine withdrawal. [2009.09]
BACKGROUND: Thyroid remnant ablation of differentiated thyroid carcinoma (DTC) patients is traditionally performed after levothyroxine withdrawal. Recombinant human TSH (rhTSH) administration increases serum TSH levels without inducing hypothyroidism. AIM: The aim of the study was to investigate the frequency of chromosome translocations in DTC patients after the first (131)I therapeutic dose and compare the frequency of translocations between DTC patients off levothyroxine and those receiving rhTSH... CONCLUSIONS: Our preliminary data show that in hypothyroid status (131)I ablation therapy induces a higher translocation rate, especially in chromosomes 4 and 8. This finding, in agreement with previous dosimetric reports, suggests that whereas inducing a low extrathyroid exposure, rhTSH reduces the potential risk of chromosomal aberration associated with blood irradiation.

Serum leptin in overt and subclinical hypothyroidism: effect of levothyroxine treatment and relationship to menopausal status and body composition. [2009.05]
BACKGROUND: The relationship between thyroid status, including subclinical hypothyroidism (SH) and serum leptin is controversial or uncertain. Therefore we evaluated serum leptin in SH and overt hypothyroidism (OH) and determined the effects of levothyroxine (LT(4)) replacement on serum leptin in these disorders... CONCLUSIONS: Serum leptin concentrations are elevated in postmenopausal women with SH or OH. A relationship between thyroid status and serum leptin is further supported by the fact that LT(4) treatment, to restore the EU status, reduced serum leptin levels in OH in the absence of significant effects on BMI. In women, hypothyroidism influences either leptin secretion or degradation and this effect is more pronounced in postmenopausal than in premenopausal women.

Efficacy of combined levothyroxine and liothyronine as compared with levothyroxine monotherapy in primary hypothyroidism: a randomized controlled trial. [2009]
OBJECTIVES: To examine the efficacy of combination therapy with levothyroxine and liothyronine in improvement of general health, psychological problems, and metabolic status in primary hypothyroidism... CONCLUSIONS: The data do not support the hypothesis that combined therapy improves the well-being and general health of patients.

Lipid profile in different degrees of hypothyroidism and effects of levothyroxine replacement in mild thyroid failure. [2008.04]
The aim of this study was to evaluate the lipid profile of patients with different degrees of hypothyroidism and the effect of levothyroxine replacement in subclinical hypothyroidism (SH). Initially, a cross-sectional study was performed with 226 participants [SH = 133 participants, manifest hypothyroidism (MH) = 23 participants, and euthyroidism (EU) = 70 participants]...

Levothyroxine in euthyroid autoimmune thyroiditis and type 1 diabetes: a randomized, controlled trial. [2007.05]
CONTEXT: Patients with type 1 diabetes (T1D) have an increased risk of autoimmune thyroiditis (AIT). OBJECTIVE: Our objective was to determine whether levothyroxine (l-T(4)) treatment prevents the clinical manifestation of AIT in euthyroid subjects with T1D... CONCLUSIONS: In this study in euthyroid patients with AIT and T1D, l-T(4) treatment reduced thyroid volume but had no effect on thyroid function and serum autoantibody levels.

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Clinical Trials Related to Levothroid (Levothyroxine)

Fasting Study of Levothyroxine Sodium Tablets 300 μg to Levothroid® Tablets 300 μg [Completed]
The objective of this study was to investigate the bioequivalence of Mylan's levothyroxine sodium 300 μg tablets to Lloyd's Levothroid® 300 μg tablets following a single 600 μg (2 x 300 μg) dose administered in healthy adult volunteers under fasting conditions. Statistical analysis of the data revealed that 90% confidence intervals were within the acceptable bioequivalent range of 80% and 125% for the natural log transformed parameters LNAUC0-48hr and LNCPEAK for baseline corrected total levothyroxine.

Fasting Study of Levothyroxine Sodium Tablets 200 mg to Synthroid Tablets 200 mg [Completed]
The objective of this study was to investigate the bioequivalence of Mylan's levothyroxine sodium 200 μg tablets to Abbott's Synthroid® 200 μg tablets following a single 600 μg (3 x 200 μg) dose administration in healthy volunteers under fasting conditions. Twenty-nine healthy, non-smoking, subjects between the ages of 18 and 47 completed this open-label, randomized, two-period, two-treatment, single-dose crossover study conducted by Dr. James D. Carlson at PRACS Institute, Ltd., Fargo, ND. Statistical analysis of the data revealed that 90% confidence intervals were within the acceptable bioequivalent range of 80% and 125% for the natural log transformed parameters LNAUC0-48hr and LNCPEAK for baseline corrected total L-thyroxine. This study demonstrated that Mylan's 200 μg levothyroxine sodium tablets are bioequivalent to Abbott's Synthroid® 200 μg tablets following a single, oral 600 μg (3 x 200 μg) dose under fasting conditions

Fasting Study of Levothyroxine Sodium Tablets 300 μg to Synthroid® Tablets 300 μg [Completed]
The objective of this study was to investigate the bioequivalence of Mylan's levothyroxine sodium 300 μg tablets to Abbott's Synthroid® 300 μg tablets following a single 600 μg (2 x 300 μg) dose administered in healthy volunteers under fasting conditions. Single-dose pharmacokinetic parameters for baseline corrected total L-thyroxine and non-baseline corrected total L-triiodothyronine were calculated using noncompartmental techniques.

Fasting Study of Levothyroxine Sodium Tablets 300 Mcg to Synthroid® Tablets 300 Mcg [Completed]
The objective of this study was to investigate the bioequivalence of Mylan's levothyroxine sodium 300 mcg tablets to Abbott's Synthroid® 300 mcg tablets following a single, oral 600 mcg dose (2 × 300 mcg) administered under fasting conditions.

Phase 4 Study in Secondary Hypothyroidism: Body Weight Adapted Thyroxin Treatment and Triiodothyronine Supplementation [Completed]
The purpose of this study is to determine whether a body weight adjusted dose of thyroxin is superior to treatment guided by laboratory results of thyroxin hormones in patients with central hypothyroidism. Moreover beneficial effects of triiodthyronine supplementation are investigated.

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PATIENT REVIEWS / RATINGS / COMMENTS

Levothroid review by 53 year old female patient
		Rating
Overall rating:
Effectiveness:		Considerably Effective
Side effects:		Mild Side Effects
		Treatment Info
Condition / reason:		hypothyroidism
Dosage & duration:		75 mcg per day (dosage frequency: daily) for the period of 5 ytears
Other conditions:		none
Other drugs taken:		none
		Reported Results
Benefits:		The treatment benefits were really not noticable because the condition of hypothyroidism ranges from non-symptomatic to many symptoms. At the time of diagnosis, I only had symptoms of mild fatigue which could have been the result of many other conditions
Side effects:		There were really no overt, obvious side effects of the treatment. levothyroxine is known to cause insomnia. It may have been coincidence, but my sleeping habits deteriorated approximately at the same time I began therapy. I am currently in the process of reducing my dose to see if sleep habits improve, but lab values remain at good levels
Comments:		As I mentioned above, my diagnosis was based almost exclusively on labratory tests. TSH and T4 (thyroid hormone) were found to be too high and too low, respectively. Relatively non-descript symptoms accompanied the list of complaints at the time of diagnosis. These symptoms improved somewhat after treatment. It is still to be determined if side effects will be improved on reduced dosage.

Levothroid review by 46 year old female patient
		Rating
Overall rating:
Effectiveness:		Considerably Effective
Side effects:		No Side Effects
		Treatment Info
Condition / reason:		hypothyroidism
Dosage & duration:		.88mg taken once daily for the period of still take it
Other conditions:		none
Other drugs taken:		none
		Reported Results
Benefits:		I had felt very tired all the time before I started taking the medication. Also my skin and hair seemed to be very dry. I have noticed a significant improvement in my energy level since taking the medication. Also my skin and hair have both improved over time.
Side effects:		I didn't have any side effects that I could associate with taking the medication.
Comments:		I take the medication first thing in the morning about 30 minutes to an hour before I eat breakfast.

Levothroid review by 46 year old female patient
		Rating
Overall rating:
Effectiveness:		Considerably Effective
Side effects:		No Side Effects
		Treatment Info
Condition / reason:		hypothyroidism
Dosage & duration:		.88mg taken once daily for the period of still take it
Other conditions:		none
Other drugs taken:		none
		Reported Results
Benefits:		I had felt very tired all the time before I started taking the medication. Also my skin and hair seemed to be very dry. I have noticed a significant improvement in my energy level since taking the medication. Also my skin and hair have both improved over time.
Side effects:		I didn't have any side effects that I could associate with taking the medication.
Comments:		I take the medication first thing in the morning about 30 minutes to an hour before I eat breakfast.