Thyroid Np 0.25gr (15mg) 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
Pharmacologic Class
Thyroid hormone replacement
Pregnancy Category
Category A
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
Thyroid, desiccated is a natural thyroid hormone replacement medicine made from dried animal thyroid glands. It contains both T4 and T3 hormones, which are essential for your body's energy, growth, and metabolism. It's used to treat an underactive thyroid (hypothyroidism) to help your body function normally.
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 consulting your doctor first.
Interactions with Other Medications and Foods
Do not take 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, away from 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 consulting your doctor first.
Interactions with Other Medications and Foods
Do not take 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, away from 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 this medicine exactly as prescribed by your doctor, usually once daily on an empty stomach, at least 30-60 minutes before breakfast or at bedtime (at least 3 hours after the last meal).
- Do not take this medicine with antacids, iron, calcium supplements, or bile acid sequestrants. Separate doses by at least 4 hours.
- Do not stop taking this medicine without consulting your doctor, even if you feel better. Lifelong therapy is often required.
- Inform your doctor about all other medications, supplements, and herbal products you are taking, as they can interact with thyroid hormones.
- Report any new or worsening symptoms to your doctor promptly.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
Initial dose typically 15-30 mg (0.25-0.5 grain) once daily, titrated slowly.
Dose Range:
15 - 180 mg
Condition-Specific Dosing:
hypothyroidism:
Initial: 15-30 mg (0.25-0.5 grain) once daily. Increase by 15 mg (0.25 grain) increments every 2-3 weeks until euthyroid state is achieved. Maintenance: 60-120 mg (1-2 grains) once daily, though some patients may require more or less. Doses should be individualized based on clinical response and laboratory parameters (TSH, free T4, free T3).
Pediatric Dosing
Neonatal:
Initial: 15 mg (0.25 grain) once daily. Adjust dose based on clinical and laboratory response. Higher doses per kg are typically required in infants and young children compared to adults.
Infant:
Initial: 15 mg (0.25 grain) once daily. Adjust dose based on clinical and laboratory response. Higher doses per kg are typically required in infants and young children compared to adults.
Child:
Initial: 15 mg (0.25 grain) once daily. Adjust dose based on clinical and laboratory response. Higher doses per kg are typically required in infants and young children compared to adults.
Adolescent:
Initial: 15-30 mg (0.25-0.5 grain) once daily. Adjust dose based on clinical and laboratory response, similar to adult titration.
Dose Adjustments
Renal Impairment:
Mild:
No specific dose adjustment generally required.
Moderate:
No specific dose adjustment generally required.
Severe:
No specific dose adjustment generally required.
Dialysis:
No specific dose adjustment generally required. Thyroid hormones are not significantly dialyzable.
Hepatic Impairment:
Mild:
No specific dose adjustment generally required.
Moderate:
No specific dose adjustment generally required.
Severe:
No specific dose adjustment generally required. Monitor thyroid function closely as metabolism may be altered.
Pharmacology
Mechanism of Action
Thyroid, desiccated, provides exogenous sources of both levothyroxine (T4) and liothyronine (T3) in a natural ratio. These hormones exert their physiologic actions through control of DNA transcription and protein synthesis. They are involved in normal metabolism, growth, and development, and are essential for maintaining metabolic rate, cardiac function, nervous system development, and muscle function.
Pharmacokinetics
Absorption:
Bioavailability:
Variable (approximately 48-80% for T4, 95% for T3), influenced by food and other medications.
Tmax:
T4: Approximately 6-8 hours; T3: Approximately 2-4 hours.
FoodEffect:
Food, especially fiber, calcium, and iron, can decrease absorption. Should be taken on an empty stomach, at least 30-60 minutes before breakfast.
Distribution:
Vd:
T4: 10-12 L; T3: 0.4-0.6 L/kg
ProteinBinding:
T4: >99% (primarily to thyroxine-binding globulin [TBG], transthyretin [prealbumin], and albumin); T3: ~99% (less avidly than T4).
CnssPenetration:
Limited (T4 and T3 cross the blood-brain barrier, but transport is regulated).
Elimination:
HalfLife:
T4: Approximately 7 days; T3: Approximately 1 day.
Clearance:
T4: 1.1 L/day; T3: 20-25 L/day
ExcretionRoute:
Primarily renal (conjugated metabolites), some biliary/fecal excretion.
Unchanged:
Minimal unchanged excretion.
Pharmacodynamics
OnsetOfAction:
Slow (days to weeks for full therapeutic effect due to T4 conversion and accumulation).
PeakEffect:
Weeks (for full stabilization of thyroid function tests).
DurationOfAction:
Weeks (due to long half-life of T4).
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate 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
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. Many people may not experience any side effects or may only have mild ones. If you are bothered by any of the following side effects or if they 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 all possible 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.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate 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
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. Many people may not experience any side effects or may only have mild ones. If you are bothered by any of the following side effects or if they 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 all possible 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.
Seek Immediate Medical Attention If You Experience:
- Symptoms of too much thyroid hormone (hyperthyroidism): Chest pain, rapid or irregular heartbeat, shortness of breath, excessive sweating, heat intolerance, nervousness, tremor, insomnia, diarrhea, significant weight loss.
- Symptoms of too little thyroid hormone (hypothyroidism): Persistent fatigue, weight gain, cold intolerance, constipation, dry skin, hair loss, depression, memory problems.
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:
+ 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 starting, stopping, or changing the dose of any medication, including this one, 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 you experienced, including any symptoms that occurred.
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 starting, stopping, or changing the dose of any medication, including this one, 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 drug may occasionally affect blood sugar control. As a result, your diabetes medications may need to be adjusted. Adhere to your doctor's instructions for monitoring your blood sugar levels and undergo blood work and other laboratory tests as directed.
If you are taking biotin or a product containing biotin, discontinue its 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 drug, as you may be more susceptible to side effects. If you are pregnant, planning to become pregnant, or are breast-feeding, consult with your doctor to weigh the 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 drug may occasionally affect blood sugar control. As a result, your diabetes medications may need to be adjusted. Adhere to your doctor's instructions for monitoring your blood sugar levels and undergo blood work and other laboratory tests as directed.
If you are taking biotin or a product containing biotin, discontinue its 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 drug, as you may be more susceptible to side effects. If you are pregnant, planning to become pregnant, or are breast-feeding, consult with your doctor to weigh the benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Headache
- Irritability
- Nervousness
- Sweating
- Diarrhea
- Palpitations
- Tachycardia (rapid heart rate)
- Arrhythmias (irregular heartbeat)
- Chest pain (angina)
- Tremor
- Insomnia
- Fever
- Heat intolerance
- Weight loss
- In severe cases: Heart failure, shock, coma, death.
What to Do:
Seek immediate medical attention or call a poison control center (1-800-222-1222). Treatment is symptomatic and supportive, including reducing absorption (e.g., activated charcoal if recent ingestion), beta-blockers for cardiac symptoms, and other supportive measures.
Drug Interactions
Major Interactions
- Anticoagulants (e.g., Warfarin): Thyroid hormones can increase the anticoagulant effect, requiring dose reduction of the anticoagulant.
- Sympathomimetics (e.g., pseudoephedrine, epinephrine): Increased risk of cardiac adverse effects.
- Tricyclic Antidepressants (TCAs): Increased sensitivity to TCAs, potentially leading to cardiac arrhythmias or CNS stimulation.
Moderate Interactions
- Antacids (aluminum, magnesium, calcium), Iron supplements, Calcium supplements, Sucralfate, Bile acid sequestrants (cholestyramine, colestipol): Can decrease absorption of thyroid hormones. Administer thyroid hormone at least 4 hours apart.
- Proton Pump Inhibitors (PPIs) and H2-receptor antagonists: May reduce gastric acidity, potentially impairing absorption of thyroid hormones.
- Antidiabetic agents (insulin, oral hypoglycemics): Thyroid hormones may increase blood glucose levels, requiring increased doses of antidiabetic agents.
- Phenytoin, Carbamazepine, Rifampin, Sertraline: May increase metabolism of thyroid hormones, requiring higher doses.
- Estrogens (oral contraceptives, hormone replacement therapy): May increase TBG levels, requiring higher doses of thyroid hormone.
- Androgens, Anabolic steroids: May decrease TBG levels, potentially requiring lower doses of thyroid hormone.
- Amiodarone, Beta-blockers, Corticosteroids: Can alter thyroid hormone metabolism or binding.
Minor Interactions
- Dietary fiber: May slightly decrease absorption.
Monitoring
Baseline Monitoring
Thyroid Stimulating Hormone (TSH)
Rationale: Primary screening and diagnostic test for hypothyroidism.
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 due to its T3 content.
Timing: Prior to initiation of therapy.
Clinical symptoms of hypothyroidism
Rationale: To establish baseline and monitor response to therapy.
Timing: Prior to initiation of therapy.
Routine Monitoring
Thyroid Stimulating Hormone (TSH)
Frequency: Every 6-8 weeks after initiation or dose change, then every 6-12 months once stable.
Target: Typically 0.4-4.0 mIU/L (individualized based on patient factors and clinical response). Some patients on desiccated thyroid may have TSH slightly suppressed but normal free T4/T3.
Action Threshold: Adjust dose if TSH is outside target range or if patient remains symptomatic.
Free Thyroxine (Free T4)
Frequency: Every 6-8 weeks after initiation or dose change, then every 6-12 months once stable.
Target: Typically within the upper half of the reference range.
Action Threshold: Adjust dose if Free T4 is outside target range or if patient remains symptomatic.
Free Triiodothyronine (Free T3)
Frequency: Every 6-8 weeks after initiation or dose change, then every 6-12 months once stable.
Target: Typically within the upper half of the reference range.
Action Threshold: Adjust dose if Free T3 is outside target range or if patient remains symptomatic.
Clinical symptoms (e.g., fatigue, weight, mood, hair/skin changes, heart rate)
Frequency: At every visit.
Target: Resolution or improvement of hypothyroid symptoms.
Action Threshold: Consider dose adjustment or further investigation if symptoms persist or worsen.
Symptom Monitoring
- Fatigue
- Weight changes (gain or loss)
- Cold intolerance
- Constipation
- Dry skin
- Hair loss
- Bradycardia (slow heart rate)
- Depression
- Memory impairment
- Muscle aches
- Nervousness
- Irritability
- Heat intolerance
- Palpitations
- Tremor
- Diarrhea
- Insomnia
- Weight loss (unintended)
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. Desiccated thyroid is Category A, meaning adequate and well-controlled studies have failed to demonstrate a risk to the fetus in the first trimester (and there is no evidence of risk in later trimesters). Dose requirements may increase during pregnancy.
Trimester-Specific Risks:
First Trimester:
No increased risk of fetal abnormalities. Essential for normal fetal neurological development.
Second Trimester:
Continued essential for fetal development. Dose adjustments may be needed.
Third Trimester:
Continued essential for fetal development. Dose adjustments may be needed.
Lactation
Thyroid hormones are naturally present in breast milk in small amounts. Desiccated thyroid is considered compatible with breastfeeding (L1 - Safest). It is essential for the mother's health and does not pose a significant risk to the nursing infant at therapeutic doses.
Infant Risk:
Low risk. Monitor infant for signs of hyperthyroidism (e.g., poor weight gain, irritability, tachycardia) if maternal doses are very high, though this is rare.
Pediatric Use
Essential for normal growth and development, including skeletal maturation and central nervous system development. Untreated congenital hypothyroidism can lead to irreversible mental retardation and growth retardation. Dosing is weight-based and requires careful monitoring of TSH, free T4, and free T3. Higher doses per kg are typically required in infants and young children.
Geriatric Use
Elderly patients may be more sensitive to the effects of thyroid hormones, particularly cardiac effects. Initiate therapy with lower doses and titrate slowly. Monitor for signs of hyperthyroidism and cardiac adverse effects. Co-morbidities and polypharmacy should be considered.
Clinical Information
Clinical Pearls
- Desiccated thyroid contains both T4 and T3, which may be preferred by some patients over levothyroxine (T4 only) due to perceived better symptom control, although evidence for superiority is mixed.
- Dosing is often in grains (gr) or milligrams (mg); 1 grain = 60 mg. The 0.25gr (15mg) tablet is a common starting dose.
- Absorption can be variable and is affected by food, supplements (calcium, iron), and certain medications. Consistent timing relative to meals and other medications is crucial.
- Monitoring should include TSH, free T4, and free T3, as TSH alone may not always reflect optimal dosing with desiccated thyroid due to the direct T3 component.
- Patients should be educated on symptoms of both hypo- and hyperthyroidism, as dose adjustments are based on both lab values and clinical response.
- Not indicated for weight loss in euthyroid individuals; misuse can lead to serious adverse effects.
Alternative Therapies
- Levothyroxine (synthetic T4): Most commonly prescribed thyroid hormone replacement.
- Liothyronine (synthetic T3): Used in specific cases, often in combination with levothyroxine, or for short-term T3 suppression.
- Combination therapy (Levothyroxine + Liothyronine): Some patients may benefit from a combination of synthetic T4 and T3.
Cost & Coverage
Average Cost:
Varies widely, typically $15-$50 per 30 tablets (15mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (preferred generic)
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 this 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.