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Levothyroxine capsules

What are levothyroxine capsules?

LEVOTHYROXINE acts as a replacement for people whose thyroid gland does not produce enough thyroid hormone. This medicine can improve symptoms of thyroid deficiency such as slow speech, lack of energy, weight gain, hair loss, dry thick skin and unusual sensitivity to cold. Levothyroxine also helps to treat a condition called goiter, which is an enlarged thyroid gland.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

  • angina

  • diabetes

  • heart disease

  • high blood pressure

  • low levels of pituitary hormone

  • dieting or on a weight loss program

  • previous heart attack

  • an unusual or allergic reaction to levothyroxine, other thyroid hormones, other medicines, foods, dyes, or preservatives

  • pregnant or trying to get pregnant

How should I take this medicine?

Take this medicine by mouth with a full glass of water. Take it on an empty stomach, 30—60 minutes before a meal. Do not crush or cut open the capsules. Follow the directions on the prescription label. Take your doses at regular intervals. Do not take your medicine more often than directed. Do not stop taking except on your doctor's advice.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What drug(s) may interact with this medicine?

  • amiodarone

  • antacids

  • calcium supplements, like Tums® and many others

  • carbamazepine

  • cholestyramine

  • colestipol

  • digoxin

  • female hormones, including contraceptive or birth control pills

  • ketamine

  • medicines for colds and breathing difficulties

  • medicines for diabetes

  • medicines for mental depression

  • medicines or herbals used to decrease weight or appetite

  • phenobarbital or other barbiturate medications

  • phenytoin

  • prednisone or other corticosteroids

  • rifabutin

  • rifampin

  • soy isoflavones

  • sucralfate

  • theophylline

  • warfarin

Tell your prescriber or health care professional about all other medicines you are taking, including non-prescription medicines, nutritional supplements, or herbal products. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check with your health care professional before stopping or starting any of your medicines.

What should I watch for while taking this medicine?

If you are taking this medicine for an underactive thyroid, it may be several weeks before you notice an improvement. Check with your doctor if your symptoms do not improve or if you develop any of the above side effects. It may be necessary for you to take this medicine for the rest of your life; do not stop taking except on your doctor's advice.

Do not switch brands of this medicine unless your prescriber agrees with the change. Ask your doctor for advice if you are uncertain.

If you are going to have surgery, tell your doctor that you are taking this medicine.

What side effects may I notice from taking levothyroxine?

Side effects that you should report to your prescriber or health care professional as soon as possible:

  • difficulty breathing, wheezing, or shortness of breath

  • chest pain

  • excessive sweating or intolerance to heat

  • fast or irregular heartbeat or pulse rate

  • nervousness

  • skin rash or hives

  • swelling of ankles, feet or legs

Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):

  • changes in appetite

  • changes in menstrual periods

  • diarrhea

  • fever

  • hair loss

  • headache

  • irritability

  • nausea, vomiting

  • tremors

  • trouble sleeping

  • weight loss

Where can I keep my medicine?

Keep out of the reach of children.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light and moisture. Keep container tightly closed. Throw away any unused medicine after the expiration date.

Levothyroxine injection

What is levothyroxine injection?

LEVOTHYROXINE (Synthroid®, Levothroid®) acts as a replacement for people whose thyroid gland does not produce enough thyroid hormone. Levothyroxine can improve symptoms of thyroid deficiency such as slow speech, lack of energy, weight gain, hair loss, dry thick skin and unusual sensitivity to cold. Levothyroxine also helps to treat a condition called goiter, which is an enlarged thyroid gland. Generic levothyroxine injections are available.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

  • angina

  • diabetes mellitus

  • heart disease

  • high blood pressure

  • low levels of pituitary hormone

  • dieting or on a weight loss program

  • previous heart attack

  • an unusual or allergic reaction to levothyroxine, other thyroid hormones, medicines, foods, dyes, or preservatives

  • pregnant or trying to get pregnant

How should I use this medicine?

Levothyroxine is for injection into a muscle or into a vein by a health care professional. For regular control of thyroid deficiency the injection is usually given into a muscle.

Contact your pediatrician or health care professional regarding the use of this medicine in children. Special care may be needed.

What if I miss a dose?

If you miss a dose, use it as soon as you can. If it is almost time for your next dose, use only that dose. Do not use double or extra doses.

What drug(s) may interact with levothyroxine?

  • amiodarone

  • carbamazepine

  • digoxin

  • female hormones, including contraceptive or birth control pills

  • ketamine

  • medicines for colds and breathing difficulties

  • medicines for diabetes

  • medicines for mental depression

  • medicines or herbals used to decrease weight or appetite

  • phenobarbital or other barbiturate medications

  • phenytoin

  • prednisone or other corticosteroids

  • rifabutin

  • rifampin

  • soy isoflavones

  • theophylline

  • warfarin

Tell your prescriber or health care professional about all other medicines you are taking, including non-prescription medicines, nutritional supplements, or herbal products. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check with your health care professional before stopping or starting any of your medicines.

What should I watch for while taking levothyroxine?

If you are receiving levothyroxine for an underactive thyroid, it may be several weeks before you notice an improvement. Check with your prescriber or health care professional if your symptoms do not improve or if you develop any of the above side effects. It may be necessary for you to take this medicine for the rest of your life; do not stop using except on your prescriber's advice.

Thyroid hormones can affect blood sugar levels. If you also have diabetes, you may need to adjust the dose of your diabetic medicine once you are stabilized on levothyroxine.

You may lose some of your hair while using levothyroxine. With time, this usually corrects itself.

If you are going to have surgery, tell your prescriber or health care professional that you are taking levothyroxine.

What side effects may I notice from receiving levothyroxine?

Side effects that you should report to your prescriber or health care professional as soon as possible:

  • difficulty breathing, wheezing, or shortness of breath

  • chest pain

  • excessive sweating or intolerance to heat

  • fast or irregular heartbeat or pulse rate

  • nervousness

  • skin rash or hives

  • swelling of ankles, feet or legs

Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):

  • changes in appetite

  • changes in menstrual periods

  • diarrhea

  • fever

  • hair loss

  • headache

  • irritability

  • leg cramps

  • nausea, vomiting

  • tremors

  • trouble sleeping

  • weight loss

Where can I keep my medicine?

Keep out of the reach of children in a container that small children cannot open.

Store undiluted injection at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light. Throw away any unused medicine after the expiration date. Once diluted, any unused injection should be discarded.

Levothyroxine tablets

What are levothyroxine tablets?

LEVOTHYROXINE (Levothroid®, Levoxyl®, Levo-T®, Synthroid®, Unithroid®, and others) acts as a replacement for people whose thyroid gland does not produce enough thyroid hormone. Levothyroxine can improve symptoms of thyroid deficiency such as slow speech, lack of energy, weight gain, hair loss, dry thick skin and unusual sensitivity to cold. Levothyroxine also helps to treat a condition called goiter, which is an enlarged thyroid gland. Generic levothyroxine tablets are available.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

  • angina

  • diabetes mellitus

  • heart disease

  • high blood pressure

  • low levels of pituitary hormone

  • dieting or on a weight loss program

  • previous heart attack

  • an unusual or allergic reaction to levothyroxine, other thyroid hormones, medicines, foods, dyes, or preservatives

  • pregnant or trying to get pregnant

How should I take this medicine?

Take levothyroxine tablets by mouth 30—60 minutes before a meal (on an empty stomach) with a full glass of water. The doses should be taken at regular intervals as indicated on the medication label. Do not take your medication more often than directed.

Contact your pediatrician or health care professional regarding the use of this medicine in children. Special care may be needed.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What drug(s) may interact with levothyroxine?

  • amiodarone

  • antacids

  • calcium supplements, like Tums® and many others

  • carbamazepine

  • cholestyramine

  • colestipol

  • digoxin

  • female hormones, including contraceptive or birth control pills

  • ketamine

  • medicines for colds and breathing difficulties

  • medicines for diabetes

  • medicines for mental depression

  • medicines or herbals used to decrease weight or appetite

  • phenobarbital or other barbiturate medications

  • phenytoin

  • prednisone or other corticosteroids

  • rifabutin

  • rifampin

  • soy isoflavones

  • sucralfate

  • theophylline

  • warfarin

Tell your prescriber or health care professional about all other medicines you are taking, including non-prescription medicines, nutritional supplements, or herbal products. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check with your health care professional before stopping or starting any of your medicines.

What should I watch for while taking levothyroxine?

If you are taking levothyroxine for an underactive thyroid, it may be several weeks before you notice an improvement. Check with your prescriber or health care professional if your symptoms do not improve or if you develop any of the above side effects. It may be necessary for you to take this medicine for the rest of your life; do not stop taking except on your prescriber's advice.

Do not switch brands of levothyroxine unless your prescriber agrees with the change. Ask your prescriber or health care professional for advice if you are uncertain.

Thyroid hormones can affect blood sugar levels. If you also have diabetes, you may need to adjust the dose of your diabetic medicine once you are stabilized on levothyroxine.

You may lose some of your hair while using levothyroxine. With time, this usually corrects itself.

If you are going to have surgery, tell your prescriber or health care professional that you are taking levothyroxine.

Be sure to take your levothyroxine tablets with a full glass of water. Certain brands of levothyroxine tablets may rapidly swell and disintegrate, which causes choking, gagging, the tablet getting stuck in your throat, or difficulty swallowing. Most of these problems disappear when the tablets are taken with water.

What side effects may I notice from taking levothyroxine?

Side effects that you should report to your prescriber or health care professional as soon as possible:

  • difficulty breathing, wheezing, or shortness of breath

  • chest pain

  • excessive sweating or intolerance to heat

  • fast or irregular heartbeat or pulse rate

  • nervousness

  • skin rash or hives

  • swelling of ankles, feet or legs

Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):

  • changes in appetite

  • changes in menstrual periods

  • diarrhea

  • fever

  • hair loss

  • headache

  • irritability

  • leg cramps

  • nausea, vomiting

  • tremors

  • trouble sleeping

  • weight loss

Where can I keep my medicine?

Keep out of the reach of children in a container that small children cannot open.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light and moisture. Keep container tightly closed. Throw away any unused medicine after the expiration date.

Publication Source: U.S. FDA-approved Package Insert
Date Last Modified: 8/8/2007