Levothyroxine 0.112mg (112mcg) Caps

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

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 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
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 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. 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, 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 and medications with your doctor.

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

Before starting, stopping, or changing the dose of any medication, including this one, consult with your doctor to confirm it is safe to do so.

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 run out of this medication, as it may take several weeks to experience its full effects.

Special Considerations

If you have diabetes (high blood sugar), consult your doctor, as this medication may affect 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 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 osteoporosis (weak bones), particularly after menopause. Discuss your risk factors with your doctor, who can help determine if you are at higher risk of developing osteoporosis.

This medication may also affect fertility, potentially leading to difficulties in getting pregnant or fathering a child. If you plan to conceive, consult your doctor before starting treatment.

Age-Related Considerations

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.

Pediatric Patients

If you are giving this medication to a child, consult your doctor if their weight changes, as the dosage may need to be adjusted. Never give your child 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, alters T4 to T3 conversion)
• Oral anticoagulants (e.g., Warfarin - enhances anticoagulant effect)
• Sympathomimetics (e.g., Epinephrine, Norepinephrine - increased risk of cardiac events)
• Tyrosine kinase inhibitors (e.g., Sunitinib, Imatinib - can alter thyroid function, requiring dose adjustment)

• Antacids (aluminum, magnesium, calcium carbonate - decrease absorption)
• Iron supplements (ferrous sulfate - decrease absorption)
• Calcium supplements (calcium carbonate, calcium citrate - decrease absorption)
• Proton pump inhibitors (PPIs - decrease absorption by increasing gastric pH)
• Sucralfate (decreases absorption)
• Cholestyramine, Colestipol (binds levothyroxine, decreases absorption)
• Soy products (can decrease absorption)
• Fiber supplements (can decrease absorption)
• Orlistat (can decrease absorption)
• Rifampin, Phenytoin, Carbamazepine, Phenobarbital (induce hepatic metabolism, increasing levothyroxine requirements)
• Estrogens (increase TBG, increasing levothyroxine requirements)
• Androgens, Anabolic steroids (decrease TBG, decreasing levothyroxine requirements)
• Beta-blockers (may reduce T4 to T3 conversion)
• Corticosteroids (may reduce T4 to T3 conversion)
• Digoxin (levothyroxine may decrease digoxin levels)
• Insulin, Oral hypoglycemics (levothyroxine may increase blood glucose, requiring dose adjustment of antidiabetics)

• Coffee (may slightly decrease absorption if taken together)

• Fatigue
• Weight changes (gain or loss)
• Cold intolerance
• Constipation
• Dry skin
• Hair loss
• Bradycardia or Tachycardia
• Palpitations
• Anxiety
• Irritability
• Tremor
• Heat intolerance
• Diarrhea
• Sleep disturbances

Levothyroxine is Category A. It is essential to continue and often increase the dose during pregnancy to maintain euthyroid state, as maternal hypothyroidism can lead to adverse fetal outcomes (e.g., impaired neurodevelopment).

Levothyroxine is compatible with breastfeeding. Minimal amounts are excreted into breast milk, and it is not expected to cause adverse effects in breastfed infants. It is considered safe for use during lactation.

Dosing is weight-based and higher per kg in younger children due to higher metabolic rates and rapid growth. Regular monitoring of TSH and T4 is critical for proper growth and neurodevelopment. Treatment is lifelong for congenital hypothyroidism.

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

• Always take levothyroxine on an empty stomach, 30-60 minutes before food or other medications, to ensure consistent absorption.
• Many medications and supplements (e.g., calcium, iron, antacids, PPIs) can interfere with levothyroxine absorption; separate administration by at least 4 hours.
• The long half-life (7 days) means that it takes 4-6 weeks for TSH levels to stabilize after a dose change, so dose adjustments should not be made more frequently than this.
• Patients should be advised to use the same brand or generic formulation consistently, as bioavailability can vary between products, potentially requiring dose adjustments.
• Symptoms of over- or under-dosing can mimic other conditions; always correlate symptoms with TSH and Free T4 levels.
• For patients with difficulty swallowing pills, Tirosint (liquid gel caps) or Tirosint-SOL (oral solution) may be options, which can also be less affected by gastric pH.

• Liothyronine (synthetic T3) - used in specific situations like myxedema coma or for short-term TSH suppression before thyroid cancer scans, but not for routine long-term hypothyroidism due to shorter half-life and fluctuating levels.

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's a good idea to check with your pharmacist for more information. 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 details about the overdose, including the medication taken, the amount, and the time it occurred.