Synthroid treats hypothyroidism (low thyroid hormone). It is also used to treat or prevent goiter (enlarged thyroid gland), which can be caused by hormone imbalances, radiation treatment, surgery, or cancer.
How to use
Use Synthroid as directed by your doctor.
Take Synthroid with a full glass (8 ounces) of water.
Take this medicine on an empty stomach, 30 minutes before eating.
Synthroid is usually taken in the morning.
Ask your health care provider any questions you may have about how to use Synthroid.
Drug Class and Mechanism
Synthroid is a replacement for a hormone that is normally produced by your thyroid gland to regulate the body's energy and metabolism. Synthroid is given when the thyroid does not produce enough of this hormone on its own.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.
Store Synthroid between 68 and 77 degrees F (20 and 25 degrees C) in a tightly closed, light-resistant container. Store away from moisture, heat, and light. Do not store in the bathroom. Do not take tablets after the expiration date printed on the label. Keep Synthroid out of the reach of children and away from pets.
Do not use Synthroid if:
you are allergic to any ingredient in Synthroid;
you have a history of heart attack, chest pain (angina), adrenal gland problems, or elevated thyroid hormone levels that have not been treated.
Contact your doctor or health care provider right away if any of these apply to you.
Synthroid may rapidly swell and disintegrate resulting in choking, gagging, the tablet getting stuck in your throat, or difficulty swallowing. It is very important that you take the tablet with a full glass of water. Most of these problems disappeared when levothyroxine tablets were taken with water.
Tell your doctor or dentist that you take Synthroid before you receive any medical or dental care, emergency care, or surgery.
If you are taking blood thinners at the same time as Synthroid, lab tests will be required to adjust the blood thinners.
Diabetes patients - Synthroid may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.
Lab tests will be required to monitor therapy. Be sure to keep appointments.
Synthroid should be used with caution in children; overuse may reduce the child's final adult height.
Pregnancy and breast-feeding: It is not known if Synthroid can cause harm to the fetus. If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Synthroid while you are pregnant. Synthroid is found in breast milk. If you are or will be breast-feeding while you use Synthroid, check with your doctor. Discuss any possible risks to your baby.
Possible Side Effects
Check with your doctor if any of these most common side effects persist or become bothersome:
anxiety; diarrhea; flushing; mood swings; muscle weakness; partial, temporary hair loss; sleeplessness; stomach cramps; tiredness; vomiting.
Seek medical attention right away if any of these severe side effects occur:
severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); changes in appetite; changes in menstrual periods; chest pain; difficulty breathing; excessive sweating; fast heartbeat; fever; headache; hives or skin rash; hyperactivity; inability to handle warm or hot room/weather conditions; irregular heartbeat; irritability; leg cramps; nervousness; pounding in the chest; seizures; shortness of breath; tremors; weight gain or weight loss.
Synthroid is to be used only by the patient for whom it is prescribed. Do not share it with other people.
If your symptoms do not improve or if they become worse, check with your doctor.