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Levoxyl (Levothyroxine Sodium) - Summary




LEVOXYL (levothyroxine sodium tablets, USP) contain 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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Published Studies Related to Levoxyl (Levothyroxine)

The effect of levothyroxine and selenomethionine on lymphocyte and monocyte cytokine release in women with Hashimoto's thyroiditis. [2011.07]
CONTEXT: No previous study determined monocyte- and lymphocyte-suppressing effects of levothyroxine and selenomethionine and assessed whether their coadministration is superior to treatment with only one of these drugs. OBJECTIVE: Our objective was to compare the effect of levothyroxine and selenomethionine on monocyte and lymphocyte cytokine release and systemic inflammation in patients with Hashimoto's thyroiditis... CONCLUSIONS: Despite affecting different types of inflammatory cells, levothyroxine and selenomethionine exhibit a similar systemic antiinflammatory effect in euthyroid females with Hashimoto's thyroiditis. This action, which correlates with a reduction in thyroid peroxidase antibody titers, may be associated with clinical benefits in the prevention and management of Hashimoto's thyroiditis, particularly in subjects receiving both agents.

Pharmacokinetic equivalence of a levothyroxine sodium soft capsule manufactured using the new food and drug administration potency guidelines in healthy volunteers under fasting conditions. [2011.06]
CONCLUSIONS: The levothyroxine soft capsule formulated with the stricter new potency guideline set forward by the Food and Drug Administration met equivalence criteria in terms of rate and extent of exposure under fasting conditions to the reference tablet formulation. Clinical doses of the capsule formulation can be given using any combination of the commercialized strengths.

Effect of levothyroxine treatment on in vitro fertilization and pregnancy outcome in infertile women with subclinical hypothyroidism undergoing in vitro fertilization/intracytoplasmic sperm injection. [2011.04]
OBJECTIVE: To investigate whether levothyroxine (LT4) treatment has beneficial effects on IVF results and pregnancy outcome in infertile patients with subclinical hypothyroidism undergoing IVF/intracytoplasmic sperm injection (ICSI)...

Metabolic effects of liothyronine therapy in hypothyroidism: a randomized, double-blind, crossover trial of liothyronine versus levothyroxine. [2011]
CONCLUSIONS: The substitution of L-T(3) for L-T(4) at equivalent doses (relative

Effects of evening vs morning levothyroxine intake: a randomized double-blind crossover trial. [2010.12.13]
BACKGROUND: Levothyroxine sodium is widely prescribed to treat primary hypothyroidism. There is consensus that levothyroxine should be taken in the morning on an empty stomach. A pilot study showed that levothyroxine intake at bedtime significantly decreased thyrotropin levels and increased free thyroxine and total triiodothyronine levels. To date, no large randomized trial investigating the best time of levothyroxine intake, including quality-of-life evaluation, has been performed... CONCLUSIONS: Levothyroxine taken at bedtime significantly improved thyroid hormone levels. Quality-of-life variables and plasma lipid levels showed no significant changes with bedtime vs morning intake. Clinicians should consider prescribing levothyroxine intake at bedtime. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN17436693 (NTR959).

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Clinical Trials Related to Levoxyl (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

Thyroid Hormone Dose Adjustment in Pregnancy [Recruiting]
Our aim is to compare the safety and efficacy of 2 different empiric levothyroxine dose adjustment recommendations to be made at the first confirmation of pregnancy in women with a history of hypothyroidism. Subjects will be women with a prior diagnosis of hypothyroidism who are taking thyroid hormone replacement and who are less than 8 weeks pregnant. Upon confirmation of pregnancy, subjects will be randomized to increase their weekly thyroid hormone dose by either 2 or 3 tablets (28 or 42%). Thyroid function will be evaluated every two weeks in the first 20 weeks and then again at week 30 and post-partum. Primary endpoints will be the proportion of women in each group who remain euthyroid throughout the first trimester and throughout pregnancy.

Study of Optimal Replacement of Thyroxine in the Elderly [Not yet recruiting]
All patients with hypothyroidism are currently treated the same way, regardless of age. The investigators want to look at whether people aged 80 years or older would benefit from being treated with lower doses of levothyroxine. There are three reasons why the investigators think this could be beneficial, but this is not yet proven:

1. Some older people with hypothyroidism may have few symptoms.

2. Doctors look at the amount of Thyroid Stimulating Hormone (TSH) in the patient's blood to decide the dose of Thyroxine received. The standard "normal" TSH range used to determine the dose of levothyroxine is from younger people. The investigators wonder whether this is appropriate to all age ranges particularly as the investigators know that older people may normally have higher TSH values.

3. If TSH levels are too low there may be a slight increased risk of problems such as brittle bones or an irregular heartbeat.

The best way to test whether older people benefit from lower doses of levothyroxine is by a large clinical trial. Before the investigators can do this, the investigators need to run a smaller clinical trial called a "pilot study" (SORTED 1) to examine whether this is practical and acceptable. The pilot study aims to recruit 50 patients with hypothyroidism aged 80 or above.

Participants will be randomly allocated to receive their routine or lower dose of levothyroxine. Follow-up will be conducted over approximately 25 weeks.

The investigators also propose a qualitative study (SORTED 2) to specifically understand patient's willingness to take part in a RCT and participant's experience of the intervention.

Finally, the investigators propose a retrospective cohort study of 400 treated hypothyroid patients aged 80 years or more registered in 2008 in Primary Care Practices with the aim of studying outcomes after 4 years. The cohort study will collect data required to inform a sample size calculation for a future full study where the primary outcome will be 4 year mortality.

Generic vs. Name-Brand Levothyroxine [Recruiting]
This study compares two different brands of thyroxine (thyroid hormone). Currently, pharmacists may be substituting generic formulations of thyroid hormone without your doctor knowing about this. Although a small difference in thyroid function is not significant in most healthy children, adolescents and adults, in infants and toddlers even a small difference in thyroid function can have important harmful consequences on brain development. The purpose of the present study is to learn whether the difference between brands of thyroid hormone that are currently being substituted is sufficient to cause a difference in thyroid function.

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.

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Reports of Suspected Levoxyl (Levothyroxine) Side Effects

Drug Ineffective (31)Fatigue (27)Alopecia (26)Malaise (24)Hypersensitivity (23)Feeling Abnormal (21)Dizziness (19)Anxiety (19)Rash (17)Insomnia (17)more >>


Based on a total of 24 ratings/reviews, Levoxyl has an overall score of 7.21. The effectiveness score is 7.92 and the side effect score is 8.17. The scores are on ten point scale: 10 - best, 1 - worst. Below are selected reviews: the highest, the median and the lowest rated.

Levoxyl review by 54 year old female patient

Overall rating:  
Effectiveness:   Highly Effective
Side effects:   No Side Effects
Treatment Info
Condition / reason:   hypothyroid problem
Dosage & duration:   0..150mg taken once a day for the period of 35 yrs so far
Other conditions:   none
Other drugs taken:   none
Reported Results
Benefits:   made me feel normal
Side effects:   none
Comments:   i have to take a peel every morning at the same time.if i dont and i forget i get tired its a different kind of tired though.once they stopped giving me the pill for 7 weeks and my hair started falling out i was lethargik i thought i was moving fast but i was moving very slow.i bloated up,i started to think kind of weird.i wanted to sleep all the time i was a real mess.so i take the medication consistantley the best i can.


Levoxyl review by 63 year old female patient

Overall rating:  
Effectiveness:   Considerably Effective
Side effects:   Mild Side Effects
Treatment Info
Condition / reason:   low thyroid levels
Dosage & duration:   100mcg (dosage frequency: once a day) for the period of 2years
Other conditions:   none
Other drugs taken:   none
Reported Results
Benefits:   weight loss, more energy
Side effects:   hair loss at first. subsided after a few months
Comments:   take one pill each morning on an empty stomach with a large glass of water. each 3 months have blood test to determine the need to increase or decrease the medicines dose.


Levoxyl review by 56 year old female patient

Overall rating:  
Effectiveness:   Ineffective
Side effects:   Extremely Severe Side Effects
Treatment Info
Condition / reason:   hypothyroidism
Dosage & duration:   75 mcg (dosage frequency: 1/day) for the period of 10 months
Other conditions:   allergies, high cholesterol
Other drugs taken:   n/a
Reported Results
Benefits:   Hypothyroidism was already causing me to gain weight, this garbage accelerated the weight gain. I eat one fish fillet or chicken breast/day, nothing else, now gaining 3-6 lbs./month! Since I can't find a Dr. who will treat my T3 I'm ordering Cytomel online, from what I've read it's the ticket to eliminate hypo symptoms. Shame on physicians who treat lab results rather than the patient. I don't care what the numbers are, I still feel awful!
Side effects:   FAT
Comments:   Doesn't work! It's the T3!

See all Levoxyl reviews / ratings >>

Page last updated: 2013-02-10

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