Levothyroxine 0.05mg (50mcg) Caps

Levothyroxine (L-thyroxine) is a synthetic form of the natural thyroid hormone, thyroxine (T4). It is converted to its active metabolite, liothyronine (T3), in peripheral tissues. T3 then enters the cell nucleus and binds to thyroid hormone receptors, which regulate gene expression and control various metabolic processes, including protein, fat, and carbohydrate metabolism, and influence growth and development.

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, or anxious
Shakiness
Trouble sleeping
Sensitivity to heat
Excessive sweating
Fever
Muscle cramps
Muscle weakness
Flushing
Bone pain
Changes in menstrual periods (in women)
In children: hip or knee pain, or a limp
In infants: changes in the shape of the head and face

Other Possible Side Effects

Like all medications, this drug can cause side effects. Many people experience no side effects or only mild ones. 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

This list is not exhaustive, and you may experience other side effects not mentioned here. 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.

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 your safety, 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.

Important Information for 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.

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. Monitor your blood sugar levels as directed by your doctor and undergo regular blood tests as advised.

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.

High doses of this medication may increase the risk of osteoporosis (weak bones), particularly after menopause. Discuss your risk factors with your doctor and ask about any concerns you may have regarding osteoporosis.

This medication may affect fertility, potentially making it difficult to become pregnant or father a child. If you plan to conceive, consult with your doctor before starting treatment.

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

Pregnancy and Breastfeeding

Inform your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. Your doctor will discuss the benefits and risks of this medication for you and your baby.

Special Considerations for Children

If your child is taking this medication and experiences a change in weight, consult with your doctor, as their dosage may need to be adjusted. Never give your child more of this medication than prescribed, as this may 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 discuss any concerns regarding your child's growth and development.

• Bile acid sequestrants (e.g., Cholestyramine, Colestipol): Reduce levothyroxine absorption. Administer levothyroxine at least 4 hours before or after.
• Ion exchange resins (e.g., Sevelamer, Patiromer): Reduce levothyroxine absorption. Administer levothyroxine at least 4 hours before or after.
• Sucralfate: Reduces levothyroxine absorption. Administer levothyroxine at least 4 hours before or after.
• Iron supplements (ferrous sulfate): Reduce levothyroxine absorption. Administer levothyroxine at least 4 hours before or after.
• Calcium carbonate/supplements: Reduce levothyroxine absorption. Administer levothyroxine at least 4 hours before or after.
• Antacids (aluminum hydroxide, magnesium hydroxide, simethicone): Reduce levothyroxine absorption. Administer levothyroxine at least 4 hours before or after.
• Proton pump inhibitors (e.g., Omeprazole, Lansoprazole): May reduce levothyroxine absorption by increasing gastric pH. Monitor TSH.
• Soy products/Soy flour: May reduce levothyroxine absorption. Monitor TSH.
• Dietary fiber: May reduce levothyroxine absorption. Monitor TSH.
• Warfarin: Levothyroxine may increase the anticoagulant effect of warfarin by increasing the catabolism of vitamin K-dependent clotting factors. Monitor INR/PT and adjust warfarin dose.
• Amiodarone: Can cause hypothyroidism or hyperthyroidism and alter T4 to T3 conversion. Monitor thyroid function.
• Tyrosine kinase inhibitors (e.g., Sunitinib, Imatinib): May increase levothyroxine requirements. Monitor TSH.

• Oral Contraceptives/Estrogens: May increase TBG levels, leading to increased levothyroxine requirements. Monitor TSH.
• Androgens/Anabolic steroids: May decrease TBG levels, potentially decreasing levothyroxine requirements. Monitor TSH.
• Glucocorticoids (high dose): May inhibit T4 to T3 conversion. Monitor thyroid function.
• Beta-blockers (e.g., Propranolol): May decrease T4 to T3 conversion. Monitor thyroid function.
• Antidiabetic agents (Insulin, Oral hypoglycemics): Levothyroxine may increase blood glucose levels, requiring increased doses of antidiabetic agents. Monitor blood glucose.
• Digoxin: Levothyroxine may decrease digoxin levels. Monitor digoxin levels.
• Phenytoin, Carbamazepine, Rifampin, Phenobarbital: May increase metabolism of thyroid hormones, increasing levothyroxine requirements. Monitor TSH.

• Certain foods (e.g., grapefruit juice): May slightly affect absorption, but generally not clinically significant if consistent.

• Fatigue
• Weight gain
• Cold intolerance
• Constipation
• Dry skin
• Hair loss
• Bradycardia
• Depression
• Muscle aches
• Puffiness in face/eyes
• Hoarseness

Levothyroxine is essential for normal fetal development and should be continued throughout pregnancy. Dose requirements often increase during pregnancy (by 25-50% or more) due to increased TBG levels and fetal thyroid hormone demands. TSH should be monitored frequently (e.g., every 4-6 weeks) and dose adjusted to maintain TSH in the trimester-specific target range.

Levothyroxine is considered safe during breastfeeding. Minimal amounts are excreted into breast milk, and it does not adversely affect the nursing infant. Maternal dose requirements typically return to pre-pregnancy levels postpartum.

Essential for normal growth and development. Dosing is weight-based and higher per kg in younger children. Close monitoring of TSH and Free T4 is crucial to ensure adequate treatment and prevent developmental delays. Crushing tablets for infants/young children is common, but ensure consistent administration.

Lower starting doses (e.g., 12.5-25 mcg/day) and slower titration are recommended due to increased cardiac sensitivity to thyroid hormones and higher prevalence of underlying cardiovascular disease. Monitor for signs of cardiac toxicity (e.g., angina, arrhythmias).

• Always take levothyroxine on an empty stomach, 30-60 minutes before breakfast, with water, and separate from other medications and supplements by at least 4 hours.
• Consistency is key: take it at the same time every day.
• Do not switch between different brands or generic formulations without consulting your healthcare provider, as bioavailability can vary.
• Symptoms of hypothyroidism resolve slowly over weeks to months; patience is required.
• TSH is the primary lab test for monitoring, but Free T4 may be useful in specific situations.
• Patients with pre-existing cardiac disease should start at lower doses and be titrated slowly to avoid exacerbating cardiac symptoms.

• Liothyronine (T3): Synthetic T3, shorter half-life, more potent, used in specific cases (e.g., myxedema coma, T3 suppression test).
• Desiccated Thyroid Extract (e.g., Armour Thyroid, Nature-Throid): Natural thyroid hormone from porcine thyroid glands, contains both T4 and T3. Dosing can be less precise due to variable T4/T3 ratios.
• Combination therapy (Levothyroxine + Liothyronine): Used in some patients who do not feel well on levothyroxine monotherapy, though evidence for widespread benefit is mixed.

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 happened.