Thyroid Np 2gr (120mg) Tablets
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 treat or prevent an enlarged thyroid.It is used to manage thyroid cancer.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Thyroid hormone replacement
Pharmacologic Class
Thyroid hormones
Pregnancy Category
Category A
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
This medication is a natural thyroid hormone replacement. It contains both T4 and T3 hormones, which your body needs to regulate energy, metabolism, and many other functions. It's used to treat an underactive thyroid (hypothyroidism) when your body doesn't make enough of these hormones on its own.
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. It's best to take this medication on an empty stomach.
Important Notes About Different Brands and Forms
There are various brands and forms of this medication available. Do not switch between different brands or forms without first consulting your doctor.
Interactions with Other Medications and Foods
Avoid taking colesevelam, colestipol, or cholestyramine within 4 hours before or 4 hours after taking this medication. Additionally, some foods like soybean flour (found in infant formula) may affect how this medication works in your body. Discuss this with your doctor.
Establishing a Routine
Take your medication at the same time every day. 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, avoiding the bathroom. Keep all medications in a safe location, out of reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses.
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. It's best to take this medication on an empty stomach.
Important Notes About Different Brands and Forms
There are various brands and forms of this medication available. Do not switch between different brands or forms without first consulting your doctor.
Interactions with Other Medications and Foods
Avoid taking colesevelam, colestipol, or cholestyramine within 4 hours before or 4 hours after taking this medication. Additionally, some foods like soybean flour (found in infant formula) may affect how this medication works in your body. Discuss this with your doctor.
Establishing a Routine
Take your medication at the same time every day. 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, avoiding the bathroom. Keep all medications in a safe location, out of reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses.
Lifestyle & Tips
- Take on an empty stomach, at least 30-60 minutes before breakfast or at bedtime (3-4 hours after last meal).
- Avoid taking with calcium, iron, antacids, or fiber supplements; separate by at least 4 hours.
- Take consistently at the same time each day.
- Do not stop taking this medication without consulting your doctor.
- Report any signs of over- or under-treatment to your doctor.
- Maintain a balanced diet and regular exercise as advised by your doctor.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
Individualized, typically starting at 15-30 mg (0.25-0.5 grain) daily, titrated every 2-3 weeks based on clinical response and laboratory parameters (TSH, Free T4, Free T3). 120 mg (2 grain) is a common maintenance dose.
Dose Range:
15 - 180 mg
Condition-Specific Dosing:
hypothyroidism:
Initial dose 15-30 mg daily, increased by 15 mg increments every 2-3 weeks until euthyroid state is achieved. Average maintenance dose is 60-120 mg daily. Some patients may require up to 180 mg or more.
Pediatric Dosing
Neonatal:
Initial dose 7.5-15 mg daily, adjusted based on clinical and laboratory response. Higher doses per kg are often required in infants.
Infant:
Initial dose 7.5-15 mg daily, adjusted based on clinical and laboratory response. Higher doses per kg are often required in infants.
Child:
Initial dose 15-30 mg daily, adjusted based on clinical and laboratory response. Dosing is weight-based and titrated.
Adolescent:
Initial dose 15-30 mg daily, adjusted based on clinical and laboratory response. Dosing is weight-based and titrated.
Dose Adjustments
Renal Impairment:
Mild:
No specific dose adjustment typically required, but monitor thyroid function.
Moderate:
No specific dose adjustment typically required, but monitor thyroid function.
Severe:
No specific dose adjustment typically required, but monitor thyroid function.
Dialysis:
No specific dose adjustment typically required, but monitor thyroid function. Thyroid hormones are not significantly dialyzable.
Hepatic Impairment:
Mild:
Monitor thyroid function closely; dose adjustment may be needed due to altered protein binding or metabolism.
Moderate:
Monitor thyroid function closely; dose adjustment may be needed due to altered protein binding or metabolism.
Severe:
Monitor thyroid function closely; dose adjustment may be needed due to altered protein binding or metabolism.
Pharmacology
Mechanism of Action
Thyroid, Desiccated provides exogenous thyroid hormones, primarily levothyroxine (T4) and liothyronine (T3), in a physiological ratio. These hormones regulate metabolism, growth, and development by binding to nuclear thyroid hormone receptors, modulating gene expression and protein synthesis.
Pharmacokinetics
Absorption:
Bioavailability:
Variable (T4 ~48-80%, T3 ~95%)
Tmax:
T4: 2-4 hours; T3: 1-2 hours
FoodEffect:
Food, especially fiber, calcium, iron, and soy products, can significantly decrease absorption. Should be taken on an empty stomach.
Distribution:
Vd:
T4: 10-12 L; T3: 0.4-0.7 L/kg
ProteinBinding:
Highly protein bound (>99%) to thyroid-binding globulin (TBG), transthyretin (TTR), and albumin.
CnssPenetration:
Limited (T3 crosses more readily than T4)
Elimination:
HalfLife:
T4: 6-7 days; T3: ~1 day
Clearance:
T4: ~1.1 L/day; T3: ~2.5 L/day
ExcretionRoute:
Primarily renal (conjugated metabolites), some biliary/fecal excretion.
Unchanged:
Minimal
Pharmacodynamics
OnsetOfAction:
Gradual, clinical effects may take several days to weeks to become apparent.
PeakEffect:
Weeks for full therapeutic effect (due to T4 half-life and conversion).
DurationOfAction:
Weeks (due to T4 half-life).
Safety & Warnings
BLACK BOX WARNING
Thyroid hormones, including Thyroid, Desiccated, should not be used for the treatment of obesity or for weight reduction. 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.
Side Effects
Serious Side Effects: Seek Medical Help Immediately
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 or seek medical attention right away:
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
Shakiness
Trouble sleeping
Sensitivity to heat
Excessive sweating
Changes in appetite
Unintentional weight changes
Diarrhea, stomach cramps, or vomiting
Irritability, nervousness, excitability, anxiety, or other mood changes
Fever
Muscle cramps
Muscle weakness
Flushing
Bone pain
Changes in menstrual periods
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
* Hair loss (usually temporary and resolves on its own within the first few months of treatment)
Reporting Side Effects
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
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 or seek medical attention right away:
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
Shakiness
Trouble sleeping
Sensitivity to heat
Excessive sweating
Changes in appetite
Unintentional weight changes
Diarrhea, stomach cramps, or vomiting
Irritability, nervousness, excitability, anxiety, or other mood changes
Fever
Muscle cramps
Muscle weakness
Flushing
Bone pain
Changes in menstrual periods
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
* Hair loss (usually temporary and resolves on its own within the first few months of treatment)
Reporting Side Effects
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Symptoms of too much thyroid hormone (hyperthyroidism): rapid heart rate, palpitations, chest pain, nervousness, tremor, excessive sweating, heat intolerance, unexplained weight loss, diarrhea, insomnia.
- Symptoms of too little thyroid hormone (hypothyroidism): persistent fatigue, weight gain, cold intolerance, constipation, dry skin, hair loss, depression, slow heart rate.
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 and its symptoms.
Certain health conditions, including:
+ Overactive thyroid gland (hyperthyroidism)
+ Weak adrenal gland (adrenal insufficiency)
This list is not exhaustive, and it is crucial to discuss all your health problems and medications with your doctor.
To ensure safe treatment, provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Natural products and vitamins you are using
* Any health problems you have
Before making any changes to your medication regimen, including starting, stopping, or adjusting the dose of any drug, consult with your doctor to confirm it is safe to do so.
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 and its symptoms.
Certain health conditions, including:
+ Overactive thyroid gland (hyperthyroidism)
+ Weak adrenal gland (adrenal insufficiency)
This list is not exhaustive, and it is crucial to discuss all your health problems and medications with your doctor.
To ensure safe treatment, provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Natural products and vitamins you are using
* Any health problems you have
Before making any changes to your medication regimen, including starting, stopping, or adjusting the dose of any drug, consult with your doctor to confirm it is safe to do so.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. To ensure uninterrupted treatment, do not allow your supply of this drug to run out. Please note that it may take several weeks for the full effects of this medication to become apparent.
If you have diabetes (high blood sugar), consult with your doctor, as this medication may occasionally affect 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 work and other laboratory tests as recommended.
If you are taking biotin or any products containing biotin, discontinue use at least 2 days prior to having your thyroid levels checked. This medication is derived from pork (pig) thyroid tissue, which carries a minimal risk of transmitting a viral disease. Although no cases have been reported, if you have concerns, discuss them with your doctor.
If you are 65 years or older, exercise caution when using this medication, as you may be more susceptible to side effects. Inform your doctor if you are pregnant, planning to become pregnant, or are breastfeeding. Your doctor will need to discuss the potential benefits and risks of this medication to both you and your baby.
If you have diabetes (high blood sugar), consult with your doctor, as this medication may occasionally affect 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 work and other laboratory tests as recommended.
If you are taking biotin or any products containing biotin, discontinue use at least 2 days prior to having your thyroid levels checked. This medication is derived from pork (pig) thyroid tissue, which carries a minimal risk of transmitting a viral disease. Although no cases have been reported, if you have concerns, discuss them with your doctor.
If you are 65 years or older, exercise caution when using this medication, as you may be more susceptible to side effects. Inform your doctor if you are pregnant, planning to become pregnant, or are breastfeeding. Your doctor will need to discuss the potential benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Palpitations
- Tachycardia
- Arrhythmias
- Chest pain (angina)
- Nervousness
- Irritability
- Insomnia
- Tremor
- Increased sweating
- Heat intolerance
- Weight loss
- Diarrhea
- Vomiting
- Fever
- Convulsions (rare)
- Heart failure (in susceptible individuals)
What to Do:
Seek immediate medical attention or call a poison control center (e.g., 1-800-222-1222). Treatment is symptomatic and supportive, including beta-blockers for cardiac effects and measures to reduce absorption if recent ingestion.
Drug Interactions
Contraindicated Interactions
- Acute myocardial infarction (in patients with uncorrected hypothyroidism)
- Uncorrected adrenal cortical insufficiency (Addison's disease)
- Untreated thyrotoxicosis
Major Interactions
- Anticoagulants (e.g., Warfarin): May enhance anticoagulant effect, requiring dose reduction of anticoagulant.
- Antidiabetic agents (e.g., Insulin, Metformin): May increase blood glucose, requiring increased dose of antidiabetic agent.
- Cardiac glycosides (e.g., Digoxin): May decrease therapeutic effect of digoxin.
- Cholestyramine, Colestipol, Sevelamer, Sucralfate: Decrease absorption of thyroid hormones. Administer 4-5 hours apart.
- Iron supplements, Calcium supplements, Aluminum/Magnesium-containing antacids: Decrease absorption of thyroid hormones. Administer 4 hours apart.
- Proton Pump Inhibitors (PPIs) and H2-receptor blockers: May reduce gastric acidity, potentially impairing absorption of thyroid hormones.
Moderate Interactions
- Estrogens (oral), Androgens: May alter thyroid hormone binding, requiring dose adjustment.
- Corticosteroids: May alter thyroid hormone metabolism.
- Amiodarone: Can cause hypo- or hyperthyroidism and alter T4 to T3 conversion.
- Beta-blockers: May reduce conversion of T4 to T3.
- Certain Antidepressants (e.g., Tricyclic antidepressants, SSRIs): May increase sensitivity to thyroid hormones or alter their metabolism.
- Orlistat: May decrease absorption of thyroid hormones.
- Phenytoin, Carbamazepine, Rifampin, Phenobarbital: May increase metabolism of thyroid hormones, requiring higher doses.
Minor Interactions
- Dietary fiber: May decrease absorption if taken concurrently.
Monitoring
Baseline Monitoring
Thyroid Stimulating Hormone (TSH)
Rationale: Primary indicator of thyroid function and adequacy of replacement.
Timing: Prior to initiation of therapy.
Free Thyroxine (Free T4)
Rationale: Assesses circulating unbound T4 levels.
Timing: Prior to initiation of therapy.
Free Triiodothyronine (Free T3)
Rationale: Assesses circulating unbound T3 levels, particularly relevant for desiccated thyroid.
Timing: Prior to initiation of therapy.
Clinical Symptoms of Hypothyroidism
Rationale: To establish baseline and track improvement.
Timing: Prior to initiation of therapy.
Cardiac Status (ECG, heart rate, blood pressure)
Rationale: To assess for underlying cardiac disease, especially in elderly or those with pre-existing conditions, as thyroid hormones can increase cardiac workload.
Timing: Prior to initiation of therapy.
Routine Monitoring
Thyroid Stimulating Hormone (TSH)
Frequency: Every 6-8 weeks until stable, then every 6-12 months.
Target: Typically 0.4-4.0 mIU/L (individualized based on patient and clinical context). Some patients on NDT may have slightly suppressed TSH with normal Free T4/T3.
Action Threshold: Above or below target range, indicating need for dose adjustment.
Free Thyroxine (Free T4)
Frequency: Every 6-8 weeks until stable, then every 6-12 months.
Target: Reference range (e.g., 0.8-1.8 ng/dL).
Action Threshold: Above or below target range, indicating need for dose adjustment.
Free Triiodothyronine (Free T3)
Frequency: Every 6-8 weeks until stable, then every 6-12 months (especially if symptoms persist despite normal TSH/Free T4).
Target: Reference range (e.g., 2.3-4.2 pg/mL).
Action Threshold: Above or below target range, indicating need for dose adjustment.
Clinical Symptoms (e.g., fatigue, weight, mood, hair loss, cold intolerance, heart rate)
Frequency: At each visit.
Target: Resolution or significant improvement of hypothyroid symptoms.
Action Threshold: Persistent or worsening symptoms, or development of hyperthyroid symptoms.
Symptom Monitoring
- Fatigue
- Weight changes (gain or loss)
- Cold or heat intolerance
- Constipation or diarrhea
- Dry skin, hair loss
- Bradycardia or tachycardia
- Palpitations
- Nervousness, irritability, anxiety
- Tremor
- Sleep disturbances
- Menstrual irregularities
Special Patient Groups
Pregnancy
Thyroid hormone replacement is essential during pregnancy for both maternal and fetal health. Hypothyroidism during pregnancy can lead to adverse outcomes for both mother and child. Dosage requirements may increase during pregnancy.
Trimester-Specific Risks:
First Trimester:
Crucial for fetal neurological development. Untreated maternal hypothyroidism can lead to impaired neurocognitive development in the fetus.
Second Trimester:
Continued need for adequate thyroid hormone levels.
Third Trimester:
Continued need for adequate thyroid hormone levels; dose may need further adjustment.
Lactation
Thyroid hormones are excreted in breast milk in minimal amounts and are generally considered compatible with breastfeeding. No adverse effects on the infant have been reported.
Infant Risk:
L1 (Safest)
Pediatric Use
Essential for normal growth and development. Under-treatment can lead to irreversible mental retardation and growth retardation. Dosing is weight-based and requires careful titration and monitoring.
Geriatric Use
Start with lower doses and titrate slowly due to increased sensitivity to thyroid hormones and a higher prevalence of cardiovascular disease. Monitor for cardiac symptoms (e.g., angina, arrhythmias).
Clinical Information
Clinical Pearls
- Thyroid, Desiccated contains both T4 and T3, which may be preferred by some patients who do not feel well on levothyroxine (T4 only) despite normal TSH.
- The potency of desiccated thyroid is standardized by iodine content, but the exact T4:T3 ratio can vary slightly between batches and manufacturers.
- Patients switching from levothyroxine to desiccated thyroid or vice versa require careful dose conversion and close monitoring of thyroid function tests and clinical symptoms.
- Absorption can be highly variable and is significantly affected by food, supplements (calcium, iron), and certain medications. Consistent administration is key.
- TSH levels may be slightly suppressed in some patients on desiccated thyroid, even when clinically euthyroid and with normal free T4/T3 levels. Clinical assessment and free hormone levels are crucial for monitoring.
- Educate patients on symptoms of both hypo- and hyperthyroidism to ensure timely reporting of adverse effects or inadequate treatment.
Alternative Therapies
- Levothyroxine (synthetic T4, e.g., Synthroid, Levoxyl)
- Liothyronine (synthetic T3, e.g., Cytomel)
- Combination therapy of Levothyroxine and Liothyronine (off-label use of separate products)
Cost & Coverage
Average Cost:
Varies widely by brand and pharmacy. Check current pricing. per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Often Tier 1 or Tier 2 for generic/preferred brand.
General Drug Facts
If your symptoms or health issues persist or worsen, it's 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 be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it occurred.