Levothyroxine 0.2mg (200mcg) Tab

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

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
Changes in appetite
Unintentional weight change
Diarrhea, stomach cramps, or vomiting
Mood changes, such as irritability, nervousness, excitability, anxiety, or other emotional changes
Shakiness
Trouble sleeping
Sensitivity to heat
Excessive sweating
Fever
Muscle cramps
Muscle weakness
Flushing
Bone pain
Changes in menstrual period (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 is not an exhaustive list of 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.

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 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.

When taking biotin or products containing biotin, stop using them 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, who can help determine if you are at a higher risk of developing 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 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 weight changes, consult with your doctor, as their 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 discuss any concerns.

• Bile acid sequestrants (e.g., cholestyramine, colestipol): Reduce levothyroxine absorption. Separate administration by 4-5 hours.
• Ion exchange resins (e.g., sevelamer, patiromer): Reduce levothyroxine absorption. Separate administration by 4-5 hours.
• Sucralfate: Reduces levothyroxine absorption. Separate administration by 4-5 hours.
• Iron supplements (ferrous sulfate): Reduce levothyroxine absorption. Separate administration by 4 hours.
• Calcium supplements (calcium carbonate, calcium citrate): Reduce levothyroxine absorption. Separate administration by 4 hours.
• Antacids (aluminum and magnesium hydroxide): Reduce levothyroxine absorption. Separate administration by 4 hours.
• Proton pump inhibitors (e.g., omeprazole, lansoprazole): May reduce levothyroxine absorption by increasing gastric pH. Monitor TSH.
• Warfarin: Levothyroxine may potentiate the anticoagulant effect of warfarin, increasing risk of bleeding. Monitor INR closely, especially when initiating or changing levothyroxine dose.
• Amiodarone: Can cause hypo- or hyperthyroidism and alter T4 to T3 conversion. Monitor thyroid function.
• Tyrosine kinase inhibitors (e.g., imatinib, sunitinib): May increase levothyroxine requirements. Monitor TSH.

• SSRIs (e.g., sertraline): May increase levothyroxine requirements. Monitor TSH.
• Tricyclic antidepressants (e.g., amitriptyline): May increase levothyroxine requirements. Monitor TSH.
• Oral contraceptives/Estrogens: Increase TBG, potentially increasing levothyroxine requirements. Monitor TSH.
• Androgens/Anabolic steroids: Decrease TBG, potentially decreasing levothyroxine requirements. Monitor TSH.
• Glucocorticoids (e.g., prednisone): May inhibit T4 to T3 conversion. Monitor thyroid function.
• Beta-blockers (e.g., propranolol): May inhibit peripheral conversion of T4 to T3.
• Diabetes medications (insulin, oral hypoglycemics): Levothyroxine may increase blood glucose levels, requiring adjustment of antidiabetic therapy.
• Protease inhibitors (e.g., ritonavir): May alter thyroid hormone metabolism. Monitor TSH.

• Dietary fiber: May reduce absorption if taken concurrently.

• Fatigue
• Weight changes (gain or loss)
• Cold intolerance
• Constipation
• Dry skin
• Hair loss
• Bradycardia (slow heart rate)
• Depression
• Memory impairment
• Nervousness
• Irritability
• Heat intolerance
• Palpitations
• Tremor
• Diarrhea
• Insomnia
• Chest pain (angina)

Levothyroxine is safe and essential during pregnancy. Thyroid hormone requirements often increase during pregnancy, especially in the first trimester. Adequate thyroid hormone levels are crucial for normal fetal neurological development.

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

Crucial for normal growth and development. Dosing is weight-based and adjusted frequently, especially in infants and young children, to ensure proper physical and cognitive development. Overtreatment can lead to craniosynostosis in infants and premature epiphyseal closure in children.

Lower starting doses are often recommended due to increased sensitivity to thyroid hormones and a higher prevalence of underlying cardiovascular disease. Gradual dose titration is important to avoid cardiac adverse effects (e.g., angina, arrhythmias).

• Always take levothyroxine on an empty stomach, 30-60 minutes before breakfast, with water. Consistency in timing is key.
• Separate administration from calcium, iron, antacids, and other interacting medications by at least 4 hours.
• Do not crush or chew tablets unless specifically instructed (e.g., for infants, dissolve in a small amount of water).
• Patients should be advised against switching between different brands or generic manufacturers without consulting their physician, as bioequivalence can vary.
• TSH is the primary lab test for monitoring, but Free T4 may be useful in specific situations (e.g., central hypothyroidism, TSH suppression therapy).
• Symptoms of over- or under-treatment can mimic other conditions; always correlate with TSH levels.
• Patients with pre-existing cardiac disease should be started on lower doses and titrated slowly to avoid exacerbation of cardiac symptoms.

• Liothyronine (synthetic T3, e.g., Cytomel) - used in specific cases, often for short-term TSH suppression or in patients who do not adequately convert T4 to T3.
• Desiccated Thyroid Extract (e.g., Armour Thyroid, Nature-Throid) - natural thyroid hormone derived from porcine thyroid glands, containing both T4 and T3.

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's a good idea to check with your pharmacist. If you have any questions or concerns about this medication, don't 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 information about the medication taken, the amount, and the time it happened.