Tirosint 100mcg Capsules

Levothyroxine (T4) is a synthetic form of the natural thyroid hormone, thyroxine. It is converted to its active metabolite, liothyronine (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

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 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 or loss of consciousness
+ 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. 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 experience 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 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 crucial that you 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 with your doctor, as this medication may affect your blood sugar control. Your doctor may need to adjust your diabetes medications. Be sure to 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.

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 or answer any questions you may have.

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

Special Considerations

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

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

Pediatric Patients

If your child is taking this medication and experiences any weight changes, consult with 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 be sure to discuss this with your doctor.

• Amiodarone (can cause hypo- or hyperthyroidism)
• Antacids (aluminum, magnesium, calcium) - decrease absorption
• Bile acid sequestrants (cholestyramine, colestipol) - decrease absorption
• Cation exchange resins (sodium polystyrene sulfonate) - decrease absorption
• Iron supplements - decrease absorption
• Orlistat - decrease absorption
• Proton pump inhibitors (PPIs) - decrease absorption (due to increased gastric pH)
• Sucralfate - decrease absorption
• Soy products - decrease absorption
• Warfarin (may increase anticoagulant effect)

• Anticonvulsants (phenytoin, carbamazepine, phenobarbital) - increase metabolism
• Beta-blockers (may decrease T4 to T3 conversion)
• Estrogens (oral) - increase TBG, requiring higher levothyroxine dose
• Glucocorticoids - may decrease TSH secretion and T4 to T3 conversion
• Rifampin - increases metabolism
• SSRIs (sertraline) - may increase levothyroxine requirements
• Tyrosine kinase inhibitors (imatinib, sunitinib) - may increase levothyroxine requirements
• Diabetes medications (insulin, oral hypoglycemics) - levothyroxine may increase blood glucose, requiring adjustment of antidiabetic drugs

• Dietary fiber - may decrease absorption
• Grapefruit juice - may decrease absorption

• Fatigue
• Weight changes (gain or loss)
• Cold intolerance
• Constipation
• Dry skin
• Hair loss
• Bradycardia or tachycardia
• Nervousness
• Irritability
• Tremor
• Heat intolerance
• Palpitations
• Chest pain

Levothyroxine is essential during pregnancy for both maternal and fetal health. Hypothyroidism during pregnancy can lead to adverse outcomes for both mother and baby. Dosage requirements often increase during pregnancy (by 25-50% or more).

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

Dosing is weight-based and higher per kg than in adults, especially in neonates and infants, due to rapid growth and higher metabolic demands. Regular monitoring of TSH and Free T4 is crucial to ensure proper growth and neurocognitive development. Tirosint capsules may be preferred for children who cannot swallow tablets or require precise dosing, as the liquid can be drawn from the capsule.

Lower initial doses (e.g., 12.5-25 mcg/day) are recommended, especially in patients with underlying cardiac disease, due to increased sensitivity to thyroid hormones and potential for exacerbation of cardiac symptoms. Dose titration should be slower and more cautious. Monitor for signs of cardiac stress.

• Tirosint capsules contain levothyroxine in a liquid gel formulation, which may offer more consistent absorption compared to traditional tablet formulations, especially in patients with malabsorption issues or those taking multiple interacting medications.
• Tirosint is often preferred for patients with gastric acid suppression (e.g., on PPIs) or those with celiac disease, lactose intolerance, or other gastrointestinal absorption issues, as it is free of excipients like lactose and gluten.
• Always take levothyroxine on an empty stomach, 30-60 minutes before breakfast, and at least 4 hours apart from calcium, iron, antacids, and other interacting medications.
• Consistency is key: take the medication at the same time each day.
• Patients should be advised not to switch between different levothyroxine products (brand or generic) without consulting their physician, as bioavailability can vary.
• TSH levels are the primary guide for dose adjustment, but clinical symptoms and Free T4 should also be considered.

• Liothyronine (T3) - used in specific cases, often in combination with levothyroxine, but not as monotherapy for routine hypothyroidism.
• Desiccated thyroid extract (e.g., Armour Thyroid) - natural thyroid hormone replacement containing both T4 and T3, but variable potency and not recommended by major endocrine societies as first-line.

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, including the amount taken and the time it happened, to ensure you receive the best possible care.