Generic Synthroid treats hypothyroidism (low thyroid hormone). Levothyroxine is also used to treat or prevent goiter (enlarged thyroid gland), which can be caused by hormone imbalances, radiation treatment, surgery, or cancer. Generic Synthroid is a replacement for a hormone that is normally produced by your thyroid gland to regulate the body's energy and metabolism. Generic Synthroid is given when the thyroid does not produce enough of this hormone on its own.
Take Generic Synthroid exactly as prescribed by your doctor. Follow the directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended. Your doctor may occasionally change your dose to make sure you get the best results.
It is very important to take Generic Synthroid with a full glass (8 ounces) of water. The Generic Synthroid tablet can dissolve very quickly and swell in the throat, possibly causing choking or gagging. Take Synthroid on an empty stomach, 30 minutes before eating. Synthroid is usually taken in the morning.
Get emergency medical help if you have any of these signs of an allergic reaction to Generic Synthroid: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have a serious side effect such as:
- sleep problems (insomnia);
- feeling nervous or irritable;
- fever, hot flashes, sweating;
- pounding heartbeats or fluttering in your chest;
- changes in your menstrual periods; or
- appetite changes, weight changes.
Less serious Generic Synthroid side effects may include mild hair loss.
This is not a complete list of side effects and others may occur.
Before using this medicine, consult your doctor or pharmacist if you have overactive thyroid conditions (e.g., thyrotoxicosis), a heart attack (acute myocardial infarction), and adrenal gland problems (e.g., uncorrected adrenal insufficiency).
Avoid the following food products, which can make your body absorb less levothyroxine: infant soy formula, cotton seed meal, walnuts, and high-fiber foods.
Certain medicines can make Generic Synthroid less effective if taken at the same time. If you use any of the following drugs, avoid taking them within 4 hours before or 4 hours after you take Generic Synthroid:
- calcium carbonate (Caltrate, Citracal, Oystercal, and others);
- ferrous sulfate iron supplement;
- sucralfate (Carafate);
- sodium polystyrene sulfonate (Kayexalate, Kionex, and others);
- antacids that contain aluminum or magnesium (such as Acid Gone, Aldroxicon, Alternagel, Di-Gel, Gaviscon, Gelusil, Genaton, Maalox, Maldroxal, Milk of Magnesia, Mintox, Mylagen, Mylanta, Pepcid Complete, Rolaids, Rulox); or
- cholesterol-lowering drugs cholestyramine (Questran) and colestipol (Colestid).
If you miss a dose, take as soon as remembered; do not take if it is almost time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.
Store at room temperature between 59 and 86 degrees F (between 15 and 30 degrees C) away from moisture and sunlight. Do not store in the bathroom. Keep away from children and pets.