Levothyroxine

The dose of levothyroxine depends on how much of the hormone is needed to bring blood levels back to the normal range. This is determined by blood tests that are done in a laboratory. The starting dose will depend on your general physical condition and the severity and length of time that you have been experiencing symptoms of low thyroid hormone levels.

You should take Levothyroxine once a day at the same time every day to ensure a consistent effect. Cotton seed meal, dietary fibre, soybean flour (infant formula), or walnuts may decrease the absorption of levothyroxine.

Signs that you may be getting too much thyroid hormone may include chest pain, increased heart rate, palpitations, excessive sweating, heat intolerance, and nervousness. If you think your dose of thyroid hormone may be too high, consult your doctor as soon as possible.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones given here, do not change the way that you are using the medication without consulting your doctor.

It is important to take Levothyroxine exactly as recommended by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store Levothyroxine at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

This product is generally well tolerated and rarely causes adverse effects. When adverse effects do occur, they usually disappear on their own, without further treatment. If you think this medication may be causing adverse effects, talk to your health care professional. He or she can help you to determine whether or not the medication is the source of the problem.

Each single-dose vial contains 500 µg of levothyroxine sodium. Nonmedicinal ingredients: mannitol, tribasic sodium phosphate anhydrous, and sodium hydroxide.

Do not take Levothyroxine if you:

• are allergic to levothyroxine or any ingredients of the medication
• are having a Heart Attack
• have acute thyrotoxicosis (too much thyroid hormone in their system)
• have uncorrected adrenal insufficiency

There may be an interaction between levothyroxine and any of the following:

• Amiodarone
• antacids (e.g., aluminum hydroxide, calcium carbonate, magnesium hydroxide)
• anticonvulsants (e.g., Carbamazepine, Phenytoin, Phenobarbital)
• beta-blockers (e.g., Metoprolol, Propranolol)
• birth control pills containing estrogen
• calcium carbonate
• calcium polystyrene sulfonate
• Cholestyramine
• ciprofloxacin
• Colesevelam
• Colestipol
• corticosteroids (e.g., Dexamethasone, Hydrocortisone, prednisone)
• diabetes medications (e.g., chlorpropamide, glipizide, Glyburide, insulin, Metformin, Rosiglitazone)
• Diazepam
• diet pills
• Digoxin
• estrogens (e.g., conjugated estrogen, Estradiol, ethinyl estradiol)
• iron supplements (e.g., ferrous fumarate, ferrous gluconate, ferrous sulfate)
• lithium
• magnesium supplements (e.g., magnesium hydroxide, magnesium oxide)
• Maprotiline
• Methimazole
• multivitamins/minerals with iron, folic acid.
• Octreotide
• nicotinic acid
• Orlistat
• Propylthiouracil
• Raloxifene
• rifampin
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• sevelamer
• simethicone
• sodium polystyrene sulfonate
• certain statins (e.g., Lovastatin, Simvastatin)
• Sucralfate
• sulfonamide antibiotics ("sulfas"; e.g., sulfisoxazole, sulfamethoxazole)
• sympathomimetic medications (e.g., amphetamines)
• testosterone
• theophyllines (e.g., Aminophylline, Oxtriphylline, Theophylline)
• Tamoxifen
• thiazide diuretics (e.g., Hydrochlorothiazide)
• tricyclic antidepressants (e.g., Amitriptyline, Imipramine)
• Warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Levothyroxine. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Levothyroxine.

Bone density: Levothyroxine can cause bones to lose thickness. If you have an increased risk for Osteoporosis (bone thinning) or are taking medications that reduce bone thickness (e.g., Prednisone or antiseizure medications), before you start taking Levothyroxine, discuss with your doctor how Levothyroxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Levothyroxine, and whether any special monitoring is needed.

Your doctor may monitor your bone thickness while you are taking Levothyroxine.

Diabetes: Levothyroxine raises blood sugar levels. For people with diabetes, this may result in an increase in the requirements for insulin or antidiabetes medications. If you have diabetes or are at an increased risk of developing diabetes, discuss with your doctor how Levothyroxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Levothyroxine, and whether any special monitoring is needed.

You may need to monitor your blood sugar more closely when starting Levothyroxine or changing doses of Levothyroxine.

Heart disease: When starting levothyroxine, people with heart disease may be started on a lower dosage as it may cause the heart to work harder than it has been used to. If you have heart disease, discuss with your doctor how Levothyroxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Levothyroxine, and whether any special monitoring is needed.

Signs of getting too much or too little medication: Contact your doctor as soon as possible if you notice any signs of getting too much medication (such as chest pain, confusion, fast or irregular heartbeat, mood swings, muscle weakness, psychosis, extreme restlessness, yellow eyes or skin, or shortness of breath) or signs of not getting enough medication (such as clumsiness, coldness, Constipation, dry, puffy skin, listlessness, muscle aches, sleepiness, tiredness, weakness, or weight gain).

Weight loss: Levothyroxine should not be used for weight loss. Large doses of levothyroxine can cause serious ore even life threatening side effects especially when taken together with other medications for weight loss.

Pregnancy: Levothyroxine should be taken throughout pregnancy to regulate the levels of thyroid hormone for the pregnant mother and the developing baby. If you become pregnant while taking Levothyroxine, contact your doctor as soon as possible. Your doctor may want to monitor your thyroid function more closely while you are pregnant.

Breast-feeding: Only a small amount of thyroid hormone is passed into breast milk. The use of appropriate amounts of Levothyroxine by breast-feeding women has not been shown to cause harm for breast-fed babies.

Seniors: Seniors may be more sensitive to the effects of levothyroxine.

This medication is typically used only once a day. However, your pharmacist may have suggested a different schedule that is more appropriate for you. You should take this medication at approximately the same time each day. Important: Follow the instructions on the label. Do not use more of this product, or more often, than prescribed. It must be used regularly and continuously to maintain its beneficial effects. Be sure to keep an adequate supply on hand. To ensure effectiveness, avoid taking milk, dairy products, antacids or mineral supplements (calcium, iron, magnesium or zinc) for at least 4 hours before and after taking this medication.