Levo-T 75mcg Tablets

Manufacturer NEOLPHARMA Active Ingredient Levothyroxine Tablets(lee voe thye ROKS een) Pronunciation LEE-voe-THYE-roks-een
WARNING: Do not use this drug for weight loss. Severe and sometimes deadly side effects may happen with this drug if it is taken in large doses or with other drugs for weight loss. If you have questions, talk with the doctor. @ COMMON USES: It is used to add thyroid hormone to the body.It is used to manage thyroid cancer.It may be given to you for other reasons. Talk with the doctor.
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Drug Class
Thyroid hormone replacement
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Pharmacologic Class
Thyroid hormones
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Pregnancy Category
Category A
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FDA Approved
Jul 1960
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DEA Schedule
Not Controlled

Overview

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What is this medicine?

Levo-T is a medicine that replaces a hormone normally made by your thyroid gland. It's used to treat an underactive thyroid (hypothyroidism) or to help shrink goiters (enlarged thyroids). It helps your body's metabolism work properly.
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How to Use This Medicine

Taking Your Medication Correctly

To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely.

Take your medication on an empty stomach, at least 30 to 60 minutes before breakfast.
Some brands of this medication may be more likely to cause choking, gagging, or trouble swallowing. If you're taking one of these products, be sure to take it with a full glass of water. Check with your pharmacist if you're unsure.
If you need to, you can crush your tablet and mix it with 1 or 2 teaspoons (5 or 10 mL) of water. Take your dose right away after mixing, and do not store the mixture for future use.

Important Interactions to Consider

Do not take iron products, antacids containing aluminum or magnesium, or calcium carbonate within 4 hours before or 4 hours after taking your medication.
If you're taking other medications, they may need to be taken at a different time than your current medication. Check with your doctor or pharmacist to determine the best schedule.
Certain foods, such as soybean flour (found in infant formula), may affect how your medication works in your body. Discuss this with your doctor.
If you regularly drink grapefruit juice or eat grapefruit, talk to your doctor about potential interactions.

Using the Correct Form of Your Medication

There are different brands and forms of this medication. Do not switch between them without consulting your doctor.
Continue taking your medication as directed by your doctor or healthcare provider, even if you're feeling well.

Storing and Disposing of Your Medication

Store your medication at room temperature in a dry place, away from heat and light. Do not store it in a bathroom.
If your medication comes in a blister pack, do not remove it from the pack until you're ready to take it. Do not store the removed medication for future use.

What to Do If You Miss a Dose

If you miss a dose, take it as soon as you remember.
If it's close to the time for your next dose, skip the missed dose and return to your regular schedule.
Do not take two doses at the same time or take extra doses.
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Lifestyle & Tips

  • Take this medicine exactly as prescribed by your doctor, usually once a day on an empty stomach, 30-60 minutes before breakfast.
  • Do not take with food, calcium supplements, iron supplements, antacids, or certain other medications (e.g., sucralfate, bile acid sequestrants). Separate by at least 4 hours.
  • Take at the same time each day for best results.
  • Do not stop taking this medicine without talking to your doctor, even if you feel better. This is usually a lifelong treatment.
  • Inform your doctor about all other medications, supplements, and herbal products you are taking, as many can interact with levothyroxine.
  • Regular blood tests (TSH) are essential to ensure you are on the correct dose.

Dosing & Administration

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Adult Dosing

Standard Dose: Initial: 1.7 mcg/kg/day orally once daily. Adjust by 12.5-25 mcg increments every 4-6 weeks based on TSH levels.
Dose Range: 25 - 300 mg

Condition-Specific Dosing:

hypothyroidism_initial: 1.7 mcg/kg/day (e.g., 100-125 mcg/day for a 70 kg adult).
hypothyroidism_elderly_cardiac: Initial: 12.5-25 mcg/day; adjust slowly by 12.5-25 mcg increments every 6-8 weeks.
subclinical_hypothyroidism: 25-75 mcg/day, individualized based on TSH and symptoms.
thyroid_cancer_ts_suppression: Higher doses, typically 2.0-2.7 mcg/kg/day, to achieve TSH suppression (target TSH <0.1 mIU/L or lower depending on risk).
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Pediatric Dosing

Neonatal: Initial: 10-15 mcg/kg/day for congenital hypothyroidism. Adjust based on TSH and T4.
Infant: 0-3 months: 10-15 mcg/kg/day; 3-6 months: 8-10 mcg/kg/day; 6-12 months: 6-8 mcg/kg/day.
Child: 1-5 years: 5-6 mcg/kg/day; 6-12 years: 4-5 mcg/kg/day.
Adolescent: 12-17 years: 2-3 mcg/kg/day or 1.7 mcg/kg/day (full adult replacement dose).
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Dose Adjustments

Renal Impairment:

Mild: No specific dose adjustment required.
Moderate: No specific dose adjustment required.
Severe: No specific dose adjustment required.
Dialysis: No specific dose adjustment required; levothyroxine is highly protein-bound and not significantly removed by dialysis.

Hepatic Impairment:

Mild: No specific dose adjustment required.
Moderate: No specific dose adjustment required.
Severe: No specific dose adjustment required; however, monitor thyroid function closely as hepatic dysfunction can alter thyroid hormone metabolism and protein binding.

Pharmacology

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Mechanism of Action

Levothyroxine (T4) is a synthetic form of the natural thyroid hormone, thyroxine. It is converted to its active metabolite, liothyronine (T3), in peripheral tissues. T3 then enters the cell nucleus and binds to thyroid hormone receptors, regulating gene expression and controlling numerous metabolic processes, including protein, carbohydrate, and lipid metabolism, and influencing growth and development.
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Pharmacokinetics

Absorption:

Bioavailability: 40-80% (average 60-80%), highly variable and influenced by food and other medications.
Tmax: 2-4 hours (for T4); 24-48 hours (for T3, due to peripheral conversion).
FoodEffect: Decreased absorption when taken with food, especially fiber, calcium, iron, and soy products. Should be taken on an empty stomach, 30-60 minutes before breakfast.

Distribution:

Vd: 10-13 L (T4); 0.46 L/kg (T3).
ProteinBinding: >99% (primarily to thyroxine-binding globulin (TBG), transthyretin, and albumin).
CnssPenetration: Limited (T4), but T3 can cross the blood-brain barrier.

Elimination:

HalfLife: Approximately 7 days (euthyroid); 9-10 days (hypothyroid); 3-4 days (hyperthyroid).
Clearance: Approximately 0.05 L/hr (euthyroid).
ExcretionRoute: Primarily renal (approximately 80% of metabolites); fecal (approximately 20% of unchanged drug and metabolites).
Unchanged: Approximately 20% (fecal excretion).
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Pharmacodynamics

OnsetOfAction: Gradual, clinical effects may not be apparent for several days to weeks.
PeakEffect: Approximately 3-4 weeks after initiation or dose change, due to long half-life and need to reach steady state.
DurationOfAction: Effects persist for several weeks after discontinuation due to long half-life.

Safety & Warnings

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BLACK BOX WARNING

Thyroid hormones, including Levo-T, 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.
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Side Effects

Serious Side Effects: Seek Medical Help Right Away

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor immediately or seek medical attention:

Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high blood pressure, including:
+ Severe headache or dizziness
+ Passing out
+ Changes in eyesight
Chest pain or pressure
Fast or abnormal heartbeat
Shortness of breath
Sudden weight gain or swelling in the arms or legs
Headache
Feeling tired or weak
Changes in appetite
Unintentional weight changes
Diarrhea, stomach cramps, or vomiting
Mood changes, such as feeling irritable, nervous, excitable, anxious, or restless
Shakiness
Trouble sleeping
Sensitivity to heat
Excessive sweating
Fever
Muscle cramps
Muscle weakness
Flushing
Bone pain
Changes in menstrual periods

Additional Side Effects in Children and Infants

Children: Hip or knee pain, or a limp
Infants: Changes in the shape of the head and face

Other Possible Side Effects

Not everyone experiences side effects, and many people have only minor or no side effects at all. However, if you notice any of the following side effects or any other unusual symptoms, contact your doctor for advice:

* Hair loss (usually temporary and resolves on its own within the first few months of treatment)

Reporting Side Effects

If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
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Seek Immediate Medical Attention If You Experience:

  • Signs of too much thyroid hormone (hyperthyroidism): chest pain, fast or irregular heartbeat, shortness of breath, excessive sweating, heat intolerance, nervousness, tremors, diarrhea, significant weight loss.
  • Signs of too little thyroid hormone (hypothyroidism, if dose is too low): extreme tiredness, weight gain, constipation, dry skin, hair loss, feeling cold, depression.
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Before Using This Medicine

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
Certain health conditions, including:
+ An overactive thyroid gland
+ A weak adrenal gland
+ Difficulty swallowing
This list is not exhaustive, and it is crucial to discuss all your health problems with your doctor.

Additionally, to ensure safe treatment, tell your doctor and pharmacist about:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
All your health problems

It is vital to verify that it is safe to take this medication with all your other medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
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Precautions & Cautions

Important Information for All Patients Taking This Medication

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. To ensure continuous treatment, do not allow your supply of this medication to run out. You may not experience the full effects of this medication for several weeks.

Special Considerations

If you have diabetes (high blood sugar), consult with your doctor, as this medication may affect your blood sugar control. Your doctor may need to adjust your diabetes medications. Be sure to monitor your blood sugar levels as directed by your doctor and undergo regular blood tests as recommended.

If you are taking biotin or a product containing biotin, stop taking it at least 2 days before having your thyroid levels checked to ensure accurate test results.

Potential Risks and Side Effects

High doses of this medication may increase the risk of developing weak bones (osteoporosis), particularly after menopause. Discuss your risk factors with your doctor, who can help determine if you are at higher risk.

This medication may also affect fertility, potentially leading to difficulty getting pregnant or fathering a child. If you plan to conceive, consult with your doctor before starting this medication.

If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects.

Pregnancy and Breastfeeding

If you are pregnant, plan to become pregnant, or are breastfeeding, inform your doctor to discuss the benefits and risks of this medication to you and your baby.

Pediatric Patients

If you are giving this medication to a child and their weight changes, consult with your doctor, as the dosage may need to be adjusted. Never give your child more of this medication than prescribed, as this can increase the risk of severe side effects.

In some cases, this medication may affect growth in children and teenagers. Regular growth checks may be necessary. Consult with your doctor to monitor your child's growth and development.
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Overdose Information

Overdose Symptoms:

  • Palpitations
  • Tachycardia (fast heart rate)
  • Arrhythmias (irregular heartbeat)
  • Chest pain (angina)
  • Tremors
  • Nervousness
  • Irritability
  • Insomnia
  • Excessive sweating
  • Heat intolerance
  • Fever
  • Weight loss
  • Diarrhea
  • Vomiting
  • Seizures (rare)
  • Heart failure (rare, especially in elderly or those with pre-existing cardiac disease)

What to Do:

Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Management is supportive and symptomatic, often involving beta-blockers for cardiovascular effects and measures to reduce absorption if recent ingestion.

Drug Interactions

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Major Interactions

  • Amiodarone (can cause hypo- or hyperthyroidism, monitor thyroid function)
  • Warfarin (levothyroxine can increase anticoagulant effect, monitor INR)
  • Insulin/Oral Hypoglycemics (levothyroxine can increase glucose requirements, monitor blood glucose)
  • Digoxin (levothyroxine can decrease digoxin levels, monitor digoxin levels)
  • Ion exchange resins (e.g., Cholestyramine, Colestipol, Sevelamer, Patiromer - significantly decrease levothyroxine absorption, separate administration by 4 hours)
  • Sucralfate (decreases levothyroxine absorption, separate administration by 4 hours)
  • Proton Pump Inhibitors (e.g., Omeprazole, Lansoprazole - may decrease levothyroxine absorption due to increased gastric pH, monitor TSH)
  • H2 Receptor Blockers (e.g., Ranitidine, Cimetidine - may decrease levothyroxine absorption due to increased gastric pH, monitor TSH)
  • Antacids (Aluminum and Magnesium Hydroxide - decrease levothyroxine absorption, separate administration by 4 hours)
  • Iron supplements (Ferrous Sulfate - decrease levothyroxine absorption, separate administration by 4 hours)
  • Calcium supplements (Calcium Carbonate, Calcium Citrate - decrease levothyroxine absorption, separate administration by 4 hours)
  • Orlistat (may decrease levothyroxine absorption, separate administration by 4 hours)
  • Tyrosine Kinase Inhibitors (e.g., Sunitinib, Imatinib, Pazopanib - may alter thyroid function, monitor TSH)
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Moderate Interactions

  • Estrogens (increase TBG, may increase levothyroxine requirements)
  • Androgens (decrease TBG, may decrease levothyroxine requirements)
  • Glucocorticoids (may inhibit T4 to T3 conversion, may alter TBG)
  • Phenytoin, Carbamazepine, Rifampin, Phenobarbital (induce hepatic metabolism of thyroid hormones, may increase levothyroxine requirements)
  • Beta-blockers (e.g., Propranolol - may inhibit T4 to T3 conversion)
  • Salicylates (>2g/day - may inhibit protein binding of thyroid hormones)
  • Furosemide (>80mg - may inhibit protein binding of thyroid hormones)
  • Soy products (may decrease levothyroxine absorption, separate administration by 4 hours)
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Minor Interactions

  • Dietary fiber (may decrease absorption, take consistently)

Monitoring

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Baseline Monitoring

Thyroid Stimulating Hormone (TSH)

Rationale: Primary diagnostic test for hypothyroidism and to guide initial dosing.

Timing: Prior to initiation of therapy.

Free Thyroxine (Free T4)

Rationale: To assess baseline thyroid hormone levels and confirm diagnosis.

Timing: Prior to initiation of therapy.

Clinical symptoms of hypothyroidism

Rationale: To establish baseline symptom severity for future comparison.

Timing: Prior to initiation of therapy.

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Routine Monitoring

Thyroid Stimulating Hormone (TSH)

Frequency: Every 4-6 weeks after initiation or dose change until stable, then every 6-12 months once stable.

Target: 0.4-4.0 mIU/L (for primary hypothyroidism); individualized for TSH suppression (e.g., <0.1 mIU/L for thyroid cancer).

Action Threshold: TSH outside target range indicates need for dose adjustment.

Free Thyroxine (Free T4)

Frequency: May be checked with TSH, especially if TSH is suppressed or in central hypothyroidism.

Target: 0.8-1.8 ng/dL (or laboratory specific reference range).

Action Threshold: Abnormal levels may indicate need for dose adjustment or further investigation.

Clinical symptoms (e.g., fatigue, weight, mood, constipation, cold intolerance)

Frequency: At each visit, especially during dose titration.

Target: Resolution or improvement of hypothyroid symptoms.

Action Threshold: Persistent or worsening symptoms despite normal TSH may warrant further evaluation or dose adjustment.

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Symptom Monitoring

  • Fatigue
  • Weight changes (gain or loss)
  • Cold intolerance
  • Constipation
  • Dry skin
  • Hair loss
  • Bradycardia (slow heart rate)
  • Depression or mood changes
  • Muscle aches or weakness
  • Memory impairment or difficulty concentrating
  • Nervousness, irritability, palpitations, tremors (signs of overtreatment/hyperthyroidism)

Special Patient Groups

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Pregnancy

Levothyroxine is essential for normal fetal development and is safe and often required during pregnancy. Thyroid hormone requirements typically increase during pregnancy (by 25-50% or more).

Trimester-Specific Risks:

First Trimester: Untreated maternal hypothyroidism in the first trimester is associated with increased risk of miscarriage, preterm birth, and impaired neurocognitive development in the child. Levothyroxine is Category A.
Second Trimester: Continued need for increased dose. Fetal thyroid gland begins to function, but maternal thyroid hormone remains crucial.
Third Trimester: Continued need for increased dose. Monitor TSH every 4-6 weeks and adjust dose to maintain TSH in the trimester-specific reference range.
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Lactation

Levothyroxine is compatible with breastfeeding (L1). Only small amounts are excreted into breast milk, which are not clinically significant to the infant.

Infant Risk: Low risk to infant. No adverse effects reported in breastfed infants.
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Pediatric Use

Dosing is weight-based and higher per kg in younger children due to higher metabolic rates. Crucial for normal growth and neurocognitive development. Close monitoring of TSH and Free T4 is essential, especially in infants with congenital hypothyroidism, to prevent irreversible intellectual disability.

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Geriatric Use

Lower initial doses (12.5-25 mcg/day) are recommended, especially in patients with pre-existing cardiac disease, due to increased sensitivity to thyroid hormones and potential for cardiac adverse effects. Dose adjustments should be made slowly (every 6-8 weeks).

Clinical Information

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Clinical Pearls

  • Always administer levothyroxine on an empty stomach, 30-60 minutes before breakfast, and at least 4 hours apart from calcium, iron, antacids, and other interacting medications.
  • Consistency is key: patients should take the medication at the same time each day.
  • TSH is the primary lab test for monitoring, but Free T4 may be useful in specific situations (e.g., central hypothyroidism, TSH suppression therapy, or when TSH is suppressed).
  • The long half-life (7 days) means it takes 4-6 weeks to reach steady state and for TSH levels to stabilize after a dose change.
  • Patients often require dose increases during pregnancy due to increased TBG and fetal demand.
  • Counsel patients that levothyroxine is not for weight loss in euthyroid individuals and can cause serious side effects if misused for this purpose.
  • Different brands of levothyroxine may have slight differences in bioavailability; generally, it's recommended to stick to the same brand once stable, or monitor TSH closely if switching.
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Alternative Therapies

  • Liothyronine (T3) - used in specific cases, e.g., myxedema coma, or short-term TSH suppression before radioactive iodine scan. Shorter half-life, more potent, higher risk of side effects.
  • Desiccated Thyroid Extract (e.g., Armour Thyroid) - natural thyroid hormone from porcine thyroid glands, containing both T4 and T3. Dosing can be less precise due to variable T4/T3 ratios.
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Cost & Coverage

Average Cost: $10 - $50 per 30 tablets (generic)
Generic Available: Yes
Insurance Coverage: Tier 1 (Generic) or Tier 2 (Preferred Brand)
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General Drug Facts

If your symptoms or health issues persist or worsen, it is essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it is a good idea to consult with your pharmacist. If you have any questions or concerns about this medication, do not hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide detailed information about the overdose, including the medication taken, the amount, and the time it occurred.