Euthyrox 0.05mg (50mcg) Tablets

Levothyroxine (T4) is a synthetic form of the natural thyroid hormone, L-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, which regulate gene expression, protein synthesis, and metabolic processes, including carbohydrate, lipid, and protein metabolism, and heat production. It is essential for normal growth and development, especially of the central nervous system and bone.

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 immediately or seek emergency 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 (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, provide your doctor and pharmacist with a comprehensive list of all the medications you are taking, including:
Prescription medications
Over-the-counter (OTC) medications
Natural products
* Vitamins

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 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 uninterrupted 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 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 take biotin or any products containing biotin, discontinue use 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 osteoporosis (weak bones), particularly after menopause. Discuss your individual risk factors with your doctor. Additionally, this medication may affect fertility, potentially leading to difficulties in getting pregnant or fathering a child. If you plan to conceive, consult your doctor before starting treatment.

Patients aged 65 and older should use this medication with caution, as they may be more susceptible to side effects. If you are pregnant, planning to become pregnant, or breastfeeding, discuss the benefits and risks of this medication with your doctor to ensure the best possible outcome for you and your baby.

Special Considerations for Children

If your child is taking this medication and experiences any changes in weight, consult your doctor, as their dosage may need to be adjusted. Never administer more than the prescribed dose, as this may increase the risk of severe side effects. In some cases, this medication may affect growth in children and teenagers, so regular growth checks may be necessary. Consult your doctor to discuss any concerns.

• Amiodarone (can cause hypo- or hyperthyroidism, requires close monitoring)
• Oral anticoagulants (e.g., Warfarin - may increase anticoagulant effect, requiring dose reduction of anticoagulant)
• Cholestyramine, Colestipol, Sevelamer, Sucralfate, Calcium Carbonate, Iron Sulfate, Aluminum Hydroxide (reduce levothyroxine absorption; separate administration by at least 4 hours)
• Proton Pump Inhibitors (e.g., Omeprazole - may decrease levothyroxine absorption)
• Soy products (may decrease levothyroxine absorption)
• Orlistat (may decrease levothyroxine absorption)
• Tyrosine kinase inhibitors (e.g., Sunitinib, Imatinib - may increase levothyroxine requirements)
• Phenytoin, Carbamazepine, Rifampin, Phenobarbital (increase levothyroxine metabolism, requiring higher doses)

• Beta-blockers (may decrease conversion of T4 to T3)
• Estrogens (increase TBG, potentially increasing levothyroxine requirements)
• Androgens (decrease TBG, potentially decreasing levothyroxine requirements)
• Antidiabetic agents (may alter glucose control, requiring adjustment of antidiabetic dose)
• Digoxin (levothyroxine may decrease digoxin levels, requiring digoxin dose adjustment)
• SSRIs (may affect thyroid function tests, but clinical significance often low)
• Grapefruit juice (may slightly decrease absorption, but generally not clinically significant if consistent)

• Caffeine (minimal effect on absorption)

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

Levothyroxine is Category A and is essential for normal fetal development. Thyroid hormone requirements often increase during pregnancy (by 25-50% or more). TSH should be monitored every 4-6 weeks and dose adjusted to maintain TSH in the lower half of the pregnancy-specific reference range (e.g., 0.1-2.5 mIU/L in 1st trimester, 0.2-3.0 mIU/L in 2nd/3rd trimesters).

Levothyroxine is compatible with breastfeeding. Minimal amounts are excreted into breast milk, and it is not expected to cause adverse effects in breastfed infants. Maternal thyroid hormone requirements typically return to pre-pregnancy levels postpartum, requiring dose adjustment.

Dosing is weight-based and higher per kg than in adults, especially in infants, due to higher metabolic rates and rapid growth. Regular monitoring of TSH and Free T4 is crucial to ensure proper growth and neurocognitive development. Congenital hypothyroidism requires immediate treatment to prevent irreversible intellectual disability.

Lower initial doses (e.g., 12.5-25 mcg/day) are recommended, especially in patients with underlying cardiovascular disease, due to increased sensitivity to thyroid hormones and risk of cardiac adverse events. Dose titration should be slower and more cautious. TSH target range may be slightly higher (e.g., 4-6 mIU/L) in very elderly patients without cardiac disease.

• 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 in timing and administration is crucial for stable TSH levels.
• Brand-name levothyroxine products (e.g., Synthroid, Levoxyl, Euthyrox, Unithroid, Tirosint) are not always bioequivalent to generic levothyroxine or to each other. If a patient switches brands or from brand to generic, TSH should be rechecked in 4-6 weeks.
• Patients with malabsorption syndromes (e.g., celiac disease, inflammatory bowel disease, bariatric surgery) may require higher doses or alternative formulations (e.g., liquid, gel cap).
• Symptoms of hypothyroidism can overlap with other conditions; TSH is the definitive diagnostic and monitoring tool.
• Patients should be educated on symptoms of both under- and over-treatment to report to their physician.

• Liothyronine (synthetic T3 - used in specific cases, e.g., thyroid cancer preparation, myxedema coma, or in patients who do not adequately convert T4 to T3, though controversial for routine use)

If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, 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 reporting the incident, be prepared to provide detailed information, including the name of the medication taken, the amount, and the time it occurred.