You should not use this medicine if you have had an allergic reaction to any type of thyroid hormone or to a color dye. You should not use this medicine if you have high levels of thyroid hormone in your blood (hyperthyroidism) or if you have recently had a heart attack. This medicine should not be used to treat obesity or for weight loss.
Your doctor will tell you how much of this medicine to use and how often. Your dose may need to be changed several times in order to find out what works best for you. Do not use more medicine or use it more often than your doctor tells you to.
Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way.
Take this medicine in the morning on an empty stomach. Wait at least a half hour (30 minutes) before you eat any food.
Swallow this tablet with a full glass (8 ounces) of water. This will help prevent choking or gagging on the tablet. If you still have trouble swallowing the tablet, talk to your doctor or pharmacist.
If this medicine is being given to a baby or a small child, you can crush the tablet and mix it in a small amount (1 to 2 teaspoons) of water. This mixture can be given by spoon or dropper. Do not mix the tablet with any other liquid except water, unless your doctor says it is okay. Do not store the mixture. If you do not give the medicine right after it is mixed, throw the medicine away.
Some people must take this medicine every day for the rest of their life.
If a dose is missed:
If you miss a dose or forget to use your medicine, use it as soon as you can. If it is almost time for your next dose, wait until then to use the medicine and skip the missed dose. Do not use extra medicine to make up for a missed dose.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any leftover medicine after you have finished your treatment. You will also need to throw away old medicine after the expiration date has passed.
Keep all medicine away from children and never share your medicine with anyone.
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
There are many other medicines that you should not use together with levothyroxine. This includes nonprescription (over-the-counter) medicines. Make sure your doctor knows about all other medicines you are using.
Make sure your doctor knows if you are using digoxin (Lanoxin®), a blood thinner (such as heparin, warfarin, Coumadin®) or a diabetes medicine (such as glipizide, glyburide, metformin, repaglinide, tolbutamide, Actos®, Glucotrol®, Prandin®).
Tell your doctor if you are using rifampin, medicines to treat heart problems (such as amiodarone, furosemide, propranolol, Diuril®, Inderal®, Lasix®), medicines to treat epilepsy or seizures (such as carbamazepine, diazepam, phenobarbital, phenytoin, Luminal®, Tegretol®), or pain or arthritis medicines, also called "NSAIDs" (such as aspirin, mefenamic acid, phenylbutazone, Ponstel®).
Make sure your doctor knows if you are also using medicines to treat depression (such as amitriptyline, doxepin, imipramine, maprotiline, nortriptyline, sertraline, Elavil®, Ludiomil®, Pamelor®, Sinequan®, Zoloft®), medicines to treat Parkinson's disease (such as bromocriptine, ropinirole, Parlodel®, Requip®), medicines to treat thyroid problems (such as methimazole, PTU, Tapazole®), or growth hormones (such as octreotide, somatrem, somatropin, Sandostatin®, Nutropin®).
Tell your doctor if you are also using aminoglutethimide, iodide, heroin, ketamine, methadone, mitotane, tamoxifen (Nolvadex®), or theophylline (Theo-Dur®).
Make sure your doctor knows if you are also using any estrogens, or if you are using birth control pills that contain estrogen (such as estradiol, estropipate, Activella®, Climara®, Femhrt®, Premarin®, Vivelle-Dot®).
If you are using antacids (such as Amphojel®, Maalox®, Mylanta®, Tums®), medicines to treat high cholesterol (such as cholestyramine, colestipol, Colestid®, Questran®), orlistat (Xenical®), sucralfate (Carafate®), or any medicine that contains calcium or iron, take it at least 4 hours before or 4 hours after you take levothyroxine.
Do not eat a cotton seed meal, dietary fiber, soybean flour (infant formula), or walnuts when you take this medicine.