Levothyroxine 0.088mg (88mcg) Tab

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 enters the cell nucleus and binds to thyroid hormone receptors, which regulate gene expression, leading to increased metabolic rate, protein synthesis, and effects on growth, development, and metabolism of carbohydrates, lipids, and proteins.

Serious Side Effects: Seek Medical Attention Immediately

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 medical help right away:

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, anxious, or restless
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 symptoms that bother you or do not go away, contact your doctor:

* 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 in combination 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 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 with 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.

This medication may also affect fertility, potentially leading to difficulties getting pregnant or fathering 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

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 and their weight changes, consult with your doctor, as the 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, so be sure to discuss this with your doctor.

• Amiodarone (can cause hypo- or hyperthyroidism, monitor thyroid function)
• Oral anticoagulants (e.g., Warfarin - increased anticoagulant effect, monitor INR)
• Sympathomimetics (e.g., Epinephrine, Norepinephrine - increased risk of cardiac adverse effects)
• Certain antidiabetic agents (may increase insulin/oral hypoglycemic requirements)

• Calcium carbonate/supplements (decreased levothyroxine absorption, separate by 4 hours)
• Iron supplements (decreased levothyroxine absorption, separate by 4 hours)
• Antacids (aluminum, magnesium, simethicone - decreased levothyroxine absorption, separate by 4 hours)
• Proton pump inhibitors (PPIs) (e.g., Omeprazole - decreased levothyroxine absorption, monitor TSH)
• Sucralfate (decreased levothyroxine absorption, separate by 4 hours)
• Cholestyramine, Colestipol, Sevelamer (decreased levothyroxine absorption, separate by 4 hours)
• Orlistat (decreased levothyroxine absorption, separate by 4 hours)
• Soy products/formula (decreased levothyroxine absorption, monitor TSH)
• Grapefruit juice (may decrease absorption, avoid consistent intake)
• Rifampin, Carbamazepine, Phenytoin, Phenobarbital (increased levothyroxine metabolism, may require higher dose)
• Estrogens (e.g., oral contraceptives, HRT - increased TBG, may require higher levothyroxine dose)
• Androgens (decreased TBG, may require lower levothyroxine dose)
• SSRIs (e.g., Sertraline - may affect thyroid function, monitor TSH)
• Tyrosine kinase inhibitors (e.g., Sunitinib, Imatinib - can cause hypothyroidism, monitor TSH)

• Dietary fiber (may decrease absorption, take consistently relative to meals)
• Coffee (may decrease absorption, take consistently relative to coffee intake)

• 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
• Chest pain

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

Levothyroxine is considered safe during breastfeeding. Only small amounts are excreted into breast milk, and it does not adversely affect the infant. It is compatible with breastfeeding.

Dosing is weight-based and higher per kg than in adults, especially in neonates and infants, due to higher metabolic rates and rapid growth. Close monitoring of TSH and Free T4 is crucial to ensure proper neurocognitive development. Lifelong treatment is typically required for congenital hypothyroidism.

Elderly patients, especially those with underlying cardiac disease, should be started on lower doses (e.g., 12.5-25 mcg/day) and titrated slowly to avoid precipitating cardiac events (e.g., angina, arrhythmias). TSH monitoring remains the primary guide for dose adjustment.

• Consistency is key: Advise patients to take levothyroxine at the same time every day, preferably in the morning on an empty stomach, 30-60 minutes before food or other medications.
• Separate from interacting agents: Emphasize the importance of separating levothyroxine from calcium, iron, antacids, and other interacting medications by at least 4 hours.
• Brand vs. Generic: While generally interchangeable, some clinicians prefer patients to remain on the same brand or generic manufacturer due to narrow therapeutic index and potential for slight variations in bioavailability. If switching, re-monitor TSH in 4-6 weeks.
• Symptoms vs. Labs: Always correlate patient symptoms with TSH and Free T4 levels. Symptoms alone can be misleading.
• Pregnancy Dose Increase: Anticipate and educate pregnant patients that their levothyroxine dose will likely need to increase significantly during pregnancy.
• Not for Weight Loss: Reiterate the black box warning; levothyroxine is not for weight loss in euthyroid individuals and can be dangerous if misused.

• Liothyronine (T3) - used for short-term TSH suppression (e.g., before radioactive iodine scan) or in rare cases of T4-T3 conversion defect, but has a shorter half-life and more fluctuating levels.
• Natural Desiccated Thyroid (NDT) - derived from porcine thyroid glands, contains both T4 and T3, but hormone content can be variable and not standardized like synthetic levothyroxine.

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 emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.