Levothyroxine 0.2mg (200mcg) Caps

Levothyroxine sodium is a synthetic L-isomer of thyroxine (T4), a naturally occurring thyroid hormone. It is converted to its active metabolite, L-triiodothyronine (T3), in peripheral tissues. T3 and T4 exert their metabolic effects through control of DNA transcription and protein synthesis by binding to thyroid hormone receptors in the cell nucleus. Thyroid hormones regulate metabolism, growth, and development, and affect virtually every organ system.

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 medical attention immediately:

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 heartbeat 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 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. 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 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, 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.

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 prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
Your overall health status

It is vital to verify that it is safe to take this medication in conjunction with your other medications and health conditions. Never start, stop, or adjust the dosage 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 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 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 recommended.

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.

Potential Risks and Side Effects

High doses of this medication may increase the risk of developing weak bones (osteoporosis), particularly after menopause. Discuss your risk factors with your doctor, who can help determine if you are at higher risk.

This medication may also affect fertility, potentially leading to difficulty getting pregnant or fathering a child. If you plan to conceive, consult 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

If you are pregnant, plan to become pregnant, or are breastfeeding, inform your doctor to discuss the benefits and risks of this medication to you and your baby.

Special Considerations for Children

If your child is taking this medication and experiences a change in weight, consult your doctor, as their dose 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, so consult your doctor to determine the best course of action.

• Amiodarone (can cause hypo- or hyperthyroidism, affecting levothyroxine dose)
• Antacids (aluminum, magnesium, calcium carbonate) - decrease absorption
• Bile acid sequestrants (cholestyramine, colestipol) - decrease absorption
• Cation exchange resins (sodium polystyrene sulfonate, sevelamer) - decrease absorption
• Iron supplements - decrease absorption
• Orlistat - decrease absorption
• Proton pump inhibitors (PPIs) - decrease absorption
• Sucralfate - decrease absorption
• Soy products (large amounts) - decrease absorption
• Tyrosine kinase inhibitors (e.g., imatinib, sunitinib) - can alter thyroid function, requiring dose adjustment
• Warfarin (increased anticoagulant effect due to increased catabolism of vitamin K-dependent clotting factors)

• Anticonvulsants (carbamazepine, phenytoin, phenobarbital) - increase levothyroxine metabolism
• Antidepressants (tricyclics, SSRIs) - may increase cardiac effects of levothyroxine
• Beta-blockers - may decrease conversion of T4 to T3
• Corticosteroids - may decrease TSH secretion and T4 to T3 conversion
• Estrogens (oral) - increase TBG, requiring higher levothyroxine dose
• Furosemide (high dose) - may displace T4 from binding proteins
• Iodine-containing products (e.g., contrast media) - can affect thyroid function
• Metformin - may affect TSH levels
• Oral contraceptives - increase TBG, requiring higher levothyroxine dose
• Rifampin - increases levothyroxine metabolism
• Statins - may affect thyroid hormone levels

• Dietary fiber (large amounts) - may decrease absorption
• Grapefruit juice - may slightly decrease absorption

• Fatigue
• Weight changes (gain or loss)
• Cold intolerance
• Constipation
• Dry skin
• Hair loss
• Bradycardia
• Depression
• Memory impairment
• Muscle aches
• Menstrual irregularities
• Nervousness
• Palpitations
• Tremor
• Heat intolerance
• Diarrhea
• Insomnia
• Weight loss (unintended)

Levothyroxine is essential for maintaining euthyroidism during pregnancy. Thyroid hormone requirements often increase during pregnancy (by 25-50% or more). Close monitoring of TSH is crucial.

Levothyroxine is compatible with breastfeeding (L1). Only small amounts are excreted into breast milk, and it does not adversely affect the infant.

Dosing is weight-based and higher per kg than in adults, especially in neonates and infants, due to rapid growth and development. Regular monitoring of TSH and Free T4 is essential. Treatment is lifelong for congenital hypothyroidism.

Lower initial doses are often recommended due to increased sensitivity to thyroid hormones and higher prevalence of underlying cardiovascular disease. Gradual dose titration is important. TSH target range may be slightly higher in very elderly patients.

• Levothyroxine is highly individualized; dose adjustments are based on TSH levels, clinical response, and patient-specific factors.
• Consistency is key: take at the same time each day, on an empty stomach, and separate from interacting medications/supplements.
• Capsule formulations (e.g., Tirosint) may be beneficial for patients with absorption issues or multiple interacting medications due to simpler excipients.
• Patients switching between different brands or formulations of levothyroxine should have their TSH rechecked, as bioequivalence can vary slightly.
• Symptoms of hypothyroidism resolve slowly over weeks to months; patience is required.
• Over-replacement can lead to iatrogenic hyperthyroidism, increasing risks of atrial fibrillation and osteoporosis, especially in older adults.

• Liothyronine (synthetic T3) - used for short-term TSH suppression or in specific cases of T4 to T3 conversion defect, but has a shorter half-life and more fluctuating levels.

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 reporting the incident, be prepared to provide details about the medication taken, the amount, and the time it occurred.