TIROSINT™ (levothyroxine sodium) capsules are soft gelatin capsules to be orally administered, which contain synthetic 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.
Media Articles Related to Tirosint (Levothyroxine)
This Week in the Endocrine Journals
Source: MedPage Today Endocrinology [2014.07.18]
(MedPage Today) -- Studies making an impact in endocrinology this week: levothyroxine interactions, sevelamer for type 2 diabetes?
Hypothyroidism During Pregnancy
Source: MedicineNet Thyroiditis Specialty [2014.01.09]
Title: Hypothyroidism During Pregnancy
Category: Diseases and Conditions
Created: 11/30/1999 8:49:00 PM
Last Editorial Review: 1/9/2014 12:00:00 AM
Source: MedicineNet Pendred Syndrome Specialty [2013.10.09]
Category: Diseases and Conditions
Created: 12/31/1997 12:00:00 AM
Last Editorial Review: 10/9/2013 12:00:00 AM
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. 
CONCLUSIONS: The substitution of L-T(3) for L-T(4) at equivalent doses (relative
Clinical Trials Related to Tirosint (Levothyroxine)
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
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
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
Thyroxin Treatment in Sub Clinical Hypothyroidism, on the Apnea Hypopnea Index Score, Lipids and Highly Sensitive CRP [Recruiting]
Obstructive sleep apnea (OSA) and hypothyroidism are both commonly found in clinical
practice, and share a number of symptoms and clinical features. It has been shown that
hypothyroid subjects are at high risk of developing sleep disorder breathing and OSA, and
adequate thyroxine treatment may reduce the sleep disordered breathing.. However, the
time-course and effect of treating subclinical hypothyroidism in OSA patients on the
respiratory events during sleep is not known.
Subclinical hypothyroidism is associated with an increased risk of coronary heart disease
(CHD). Dyslipidemia is a known complications of subclinical hypothyroidism and the effect of
thyroxine treatment on lipid profile is controversial . Some reports suggested higher serum
high-sensitivity C-reactive protein (hs-CRP), than healthy subjects; however, the effect of
levothyroxine is controversial.
This project will help us to know if the treatment of subclinical hypothyroidism will
improve the symptoms and reduce the progression of OSA, which may improve patients' quality
of life by reducing the complication of OSA (hypertension, , depression, Cardiovascular
diseases, etc.) or may even reduce mortality. It will help us to know the effect of
subclinical hypothyroidism treatment on of lipid profiles and hs-CRP.
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.
Reports of Suspected Tirosint (Levothyroxine) Side Effects
Heart Rate Increased (4),
Abdominal Discomfort (3),
Feeling Abnormal (3),
Abdominal Pain (2),
Coeliac Disease (2),
Chest Pain (2), more >>
PATIENT REVIEWS / RATINGS / COMMENTS
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|
|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|
|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|
|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|
|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|
|Condition / reason:|| || Hypothyroid|
|Dosage & duration:|| || 50mg taken one per day for the period of 45 days|
|Other conditions:|| || blood pressure|
|Other drugs taken:|| || diovan|
|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.|
Page last updated: 2014-07-18