Indications 

Levoxyl is a prescription medicine used to treat hypothyroidism, a condition where the thyroid gland fails to produce adequate thyroid hormones to meet the body’s requirements. 

Levoxyl is specifically indicated for the treatment of congenital or acquired primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) hypothyroidism. It can also be used along with surgery and radioiodine therapy to manage well-differentiated thyroid cancer (the most common form of thyroid malignancy). 

As a thyroid replacement hormone, Levoxyl replaces the thyroid hormone normally produced by the thyroid gland to regulate the body’s energy and metabolism.  

Levoxyl exerts its mechanisms of action by controlling DNA transcription and protein synthesis. L-thyroxine (T4) and L-triiodothyronine (T3) enter the cell nucleus and bind to thyroid receptor proteins linked to DNA, activating gene transcription and the synthesis of messenger RNA and cytoplasmic proteins. 

Uses and Dosage 

Before taking Levoxyl, and with every subsequent refill, carefully review its medication guide and patient information leaflet. Do not hesitate to consult with your doctor or pharmacist for any questions or uncertainties. 

The dosage of this medication is based on the patient’s age, weight, medical condition, lab test results, response to treatment, and concomitant medications. The initial dose is usually low and is gradually increased by the physician. 

Typically, Levoxyl is taken once daily on an empty stomach, either 30 minutes to 1 hour before breakfast or as prescribed by the doctor. Tablets should be swallowed whole with a full glass (8 ounces) of water, as they may dissolve rapidly and cause swelling in the throat. 

For infants and children who cannot swallow tablets, Levoxyl tablets may be crushed and mixed with a small amount (5 mL to 10 mL or 1 to 2 teaspoonfuls) of water, which should be administered immediately using a spoon or dropper. The mixture should not be stored or combined with foods that may impair the absorption of Levoxyl, such as soybean-based infant formula. 

To achieve optimal results, take Levoxyl regularly around the same time daily as prescribed. Do not alter the prescribed dosage and the frequency of administration without your doctor’s approval. 

Continued use of Levoxyl is necessary, even if you are feeling well. Ceasing the medication should only be done after consulting with your physician. 

Side Effects 

Listed below are potential adverse reactions associated with the use of Levoxyl. Notify your physician or pharmacist promptly if any of these symptoms persist or worsen. 

Common Side Effects 

• Chest pain and irregular heartbeats 
• Shortness of breath 
• Headache, leg cramps, muscle pain, or weakness 
• Tremors, nervousness, irritability, or trouble sleeping 
• Increased appetite and feeling hot 
• Weight loss 
• Changes in menstrual periods 
• Diarrhea 
• Skin rash or partial hair loss 

Serious Side Effects 

• Irregular or fast heartbeats 
• Chest pain or pain spreading to the jaw or shoulder 
• Shortness of breath 
• Fever, hot flashes, sweating 
• Tremors or feeling unusually cold 
• Weakness, tiredness, insomnia 
• Memory problems, depression, or irritability 
• Headache, leg cramps, muscle aches 
• Nervousness or irritability 
• Dry skin or hair, hair loss 
• Irregular menstrual periods 
• Vomiting, diarrhea, appetite, or weight changes 

Call your doctor immediately if you experience any of the severe symptoms mentioned above. 

Allergic Reactions 

While the chances of a severe allergic reaction to Levoxyl are low, prompt medical attention should be sought if it occurs. Indications of a severe allergic response may include the following: 

• Hives 
• Difficulty breathing 
• Facial, tongue, or throat itching or swelling 
• Severe dizziness 

The side effects of Levoxyl listed here are not complete. Tell your doctor immediately if any unmentioned side effects occur and cause discomfort. 

Cautions 

Before starting treatment with Levoxyl, inform your physician or pharmacist about any known hypersensitivity, especially to levothyroxine or other medications. 

This medication may include inert constituents that can potentially elicit allergic reactions or other related issues. Obtain a list of the ingredients from your pharmacist. 

To ensure Levoxyl is safe for you, disclose your medical history to your doctor, especially of: 

• Elevated thyroid hormone levels (thyrotoxicosis) 
• Reduced adrenal gland function 
• Heart disease (e.g., coronary artery disease, irregular heartbeat) 
• Hypertension (high blood pressure) 
• Diabetes 

Levoxyl  may potentially interact with certain products, including but not limited to: 

• “Blood thinners” such as warfarin 
• Digoxin 
• Sucroferric oxyhydroxide 

To prevent drug interactions, tell your healthcare provider and pharmacist about all your current and planned medications, including prescriptions, over-the-counter medicines, supplements, and herbal products. 

Some products may affect the absorption of Levoxyl. Take or administer Levoxyl: 

• At least 4 hours before or after: 
  • Calcium carbonate (Tums) 
  • Ferrous sulfate (iron supplement) 
• At least 4 hours before: 
  • Cholestyramine (Prevalite) 
  • Colesevelam (Welchol) 
  • Colestipol (Colestid) 
  • Sevelamer (Renvela, Renagel) 
  • Sodium polystyrene sulfonate (Kayexalate) 

Certain foods and drinks may impact the efficacy and dosing of Levoxyl. To ensure optimal absorption of Levoxyl, avoid consuming the following food products:  

• Grapefruit juice 
• Infant soy formula 
• Soybean flour 
• Cotton seed meal 
• Walnuts 
• High-fiber foods 

Levoxyl can be used during pregnancy, but it is essential to inform your doctor if you are pregnant, as a dose adjustment may be necessary. 

Levothyroxine can pass into breast milk but is not expected to cause harm to a nursing infant. Still, consult your doctor before breastfeeding.