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Tirosint (Levothyroxine Sodium) - Summary



  • Thyroid hormones, including TIROSINT, either alone or with other therapeutic agents, should not be used for the treatment of obesity or for weight loss.
  • In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction.
  • Larger doses may produce serious or even life threatening manifestations of toxicity, particularly when given in association with sympathomimetic amines such as those used for their anorectic effects [See Adverse Reactions (6), Drug Interactions, and Overdosage].


TIROSINT (levothyroxine sodium) is L-thyroxine. The orally administered gelatin capsules contain synthetic L-3,3',5,5'-tetraiodothyronine sodium salt [levothyroxine (T4) sodium].


TIROSINT is indicated as a 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. 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 Thyrotropin-Stimulating Hormone (TSH) Suppression

TIROSINT is indicated as an adjunct to surgery and radioiodine therapy in the management of thyrotropin- dependent well-differentiated thyroid cancer.

See all Tirosint indications & dosage >>


Media Articles Related to Tirosint (Levothyroxine)

Source: MedicineNet levothyroxine sodium Specialty [2017.04.25]
Title: Hypothyroidism
Category: Symptoms and Signs
Created: 2/26/2014 12:00:00 AM
Last Editorial Review: 4/25/2017 12:00:00 AM

Hypothyroidism During Pregnancy
Source: MedicineNet levothyroxine sodium Specialty [2016.02.03]
Title: Hypothyroidism During Pregnancy
Category: Diseases and Conditions
Created: 11/30/1999 12:00:00 AM
Last Editorial Review: 2/3/2016 12:00:00 AM

more news >>

Published Studies Related to Tirosint (Levothyroxine)

Reduction of thyroid nodule volume by levothyroxine and iodine alone and in combination: a randomized, placebo-controlled trial. [2011.09]
CONTEXT: Nodular goiter is common worldwide, but there is still debate over the medical treatment. OBJECTIVE: The objective of the study was the measurement of the effect of a treatment with (nonsuppressive) T(4), iodine, or a combination of both compared with placebo on volume of thyroid nodules and thyroid... CONCLUSION: In a region with a sufficient iodine supply, a 1-yr therapy with a combination of I and T(4) with incomplete suppression of thyrotropin reduced thyroid nodule volume further than either component alone or placebo.

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

more studies >>

Clinical Trials Related to Tirosint (Levothyroxine)

Combined Levothyroxine/Liothyronine Supplementation in Hypothyroid Patients With Brain Tumors [Terminated]
Primary Objectives: 1. Assess whether combined treatment with Levothyroxine and Liothyronine improves learning and memory. 2. Explore the relationship between T3 treatment and other domains of cognitive function, quality of life, and mood.

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.

Evaluation of the Efficacy and Safety of Levothyroxine in Brain Death Organ Donors: a Randomized Controled Trial [Recruiting]

Bioequivalence of Two Levothyroxine Tablet Formulations in Healthy Indian Volunteers [Completed]
GSK markets a drug called levothyroxine or T4 that is used to treat patients with hypothyroidism. Till date, the active drug substance or active pharmaceutical ingredient (API) for levothyroxine tablets marketed in India has been obtained from a particular source. GSK India proposes to change the source of the API from the existing source to a new source. Some patients may experience a change in clinical effect when switched from one formulation to another. Therefore this study is being done to understand whether a change in API in levothyroxine tablet has any impact on the clinical effect of the drug. The purpose of this study is to: See how quickly the levothyroxine tablet from the new source (single dose of 600mcg) enters the bloodstream, is distributed in the body, broken down and removed compared to the levothyroxine tablet from the existing source (single dose of 600mcg). Study the effect of single 600mcg doses of levothyroxine tablet from new source and levothyroxine tablet from existing source on TSH level in the blood. Study the safety and side effects of single 600mcg doses of levothyroxine tablet from new source and levothyroxine tablet from existing source.

Desiccated Thyroid Extract and Levothyroxine for Hypothyroidism Treatment [Recruiting]
Our hypothesis is that hypothyroid patients on DTE may have a decrease in symptoms, an improvement of cognitive function, and an increase in sense of well-being/ quality of life equivalently compared with L-T4.

more trials >>

Reports of Suspected Tirosint (Levothyroxine) Side Effects

Heart Rate Increased (4)Abdominal Discomfort (3)Malaise (3)Feeling Abnormal (3)Asthenia (3)Abdominal Pain (2)Thirst (2)Coeliac Disease (2)Palpitations (2)Chest Pain (2)more >>


Based on a total of 13 ratings/reviews, Tirosint has an overall score of 5.62. The effectiveness score is 5.69 and the side effect score is 7.69. The scores are on ten point scale: 10 - best, 1 - worst. Below are selected reviews: the highest, the median and the lowest rated.

Tirosint review by 52 year old female patient

Overall rating:  
Effectiveness:   Highly Effective
Side effects:   No Side Effects
Treatment Info
Condition / reason:   low thyroid
Dosage & duration:   75 mg taken 1x day for the period of First prescribed 3/07, still take daily
Other conditions:   Occasional acid reflux
Other drugs taken:   None
Reported Results
Benefits:   I had experienced decreased energy and increasing tiredness for several years. It got to the point I was taking naps for the first time since I was a small child, and still didn't feel refreshed. I also felt cold frequently and had put on a good 20 pounds in a year. When I went for my annual physical, my blood work came back with high cholesterol for the first time. I thought it was advancing middle age. Fortunately, my MD put it all together and ordered a thyroid test. I was very low. Within two weeks, I felt energized and my mood improved. I have shed some (not all, darn it) of the weight and my cholesterol score is lower.
Side effects:   I had none except for a few hot flashes (well past menopause) that went away in the first few weeks. I have never been a pill-taker for fear of side effects, but this was a good experience. Fortunately, the initial dose was effective and did not need adjustment.
Comments:   As I said, my doctor spotted the symptoms and ordered a thyroid test. When it came back very low, she prescribed 75 mg a day of levothyroxine, and I felt a little better almost immediately. Within 2 weeks, I felt younger, more energy, better mood and my weight gain stopped. I have enough energy to exercize and with only a slight shift in my fairly healthy diet to less fat and more fruits and vegetables, the weight has slowly come off. I have my thyroid checked every 6 months with good results so far. Between the medication and some dietary changes, my cholesterol is down from 230 to 206. I still have about 6 pounds to get back to my starting weight. Unless there's a permanent cure out there, I won't mind taking this little lifesaver forever.


Tirosint review by 72 year old male patient

Overall rating:  
Effectiveness:   Marginally Effective
Side effects:   No Side Effects
Treatment Info
Condition / reason:   tsh level was low no clinical symtoms
Dosage & duration:   0.025 (dosage frequency: every morning before breakfast) for the period of 9 months
Other conditions:   none
Other drugs taken:   none
Reported Results
Benefits:   cold not discern because there was no clinical symptom other than tsh leel was low.the lab test result indicate improvement in tsh level but the doctor did not increase the dosage of the drug.
Side effects:   none
Comments:   every morning i took the pill with water and waited 2 hours before breakfast. no side effects were noted. no clearcut benefits either. i am a healthy senior with no physical problem other than low level of thyroid hormone.


Tirosint review by 55 year old female patient

Overall rating:  
Effectiveness:   Ineffective
Side effects:   Extremely Severe Side Effects
Treatment Info
Condition / reason:   Hypothyroid
Dosage & duration:   50mg taken one per day for the period of 45 days
Other conditions:   blood pressure
Other drugs taken:   diovan
Reported Results
Benefits:   Initially felt good, then after a week knee pain started. Week later started getting bumps on my legs. Kept thinking I was doing something else wrong, blamed it on new shoes, etc. Knees hurt, were creaking and pain got worse. Bumps were scary.
Side effects:   Severe joint pain knees, sleeplessness, vaculitis.
Comments:   Doctor said to discontinue.

See all Tirosint reviews / ratings >>

Page last updated: 2017-04-25

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