Levothyroxine

Brand Name: Eltroxin Euthyrox Synthroid

Prescription Needed: Yes

What is this drug used for?

Levothyroxine is used to treat hypothyroidism a condition where the thyroid gland does not produce enough thyroid hormone. Without this hormone the body can't function properly with resulting poor growth slow speech a lack of energy weight gain hair loss dry thick skin and increased sensitivity to cold. Levothyroxine reverses these symptoms. It is also used to treat congenital hypothyroidism and goiter.

Levothyroxine is ineffective for weight reduction in people with normal thyroid function and may cause serious or life-threatening toxicity especially when taken with amphetamines.

Is there any reason not to take this drug?

You should not take this drug if you are allergic to levothyroxine. Before taking this medication tell your doctor specifically if you have or have ever had:

chest pain (angina) rapid heart beat (arrhythmias) high blood pressure

  • heart attack
  • under active adrenal or pituitary gland
  • diabetes
  • osteoporosis

What about possible side effects?

Side effects to levothyroxine should be minimal if you are getting the right amount of medication. Although you might experience some of these side effects when you first start therapy you might need to have your dose changed if these symptoms continue or are severe:

  •  weight loss
  • tremor
  • headache
  • upset stomach vomiting
  • diarrhea stomach cramps
  • nervousness
  • irritability
  • insomnia
  • excessive sweating
  • increased appetite
  • fever
  • changes in menstrual cycle
  • sensitivity to heat
  • temporary hair loss particularly in children during the first month of therapy

Also call your doctor immediately if you experience any of these more serious symptoms:

  • chest pain (angina)
  • rapid or irregular heartbeat or pulse

This is not a complete list of side effects. If you are concerned about these or other unusual symptoms while taking this medication ask your doctor and/or pharmacist for more information and advice.

What if I am taking other drugs?

Always provide your doctor with a list of all other drugs you are taking (including over-the-counter medications and herbal/natural products) as they may interact and may change the safety or effectiveness of either drug. Tell your doctor specifically if you are taking any of these drugs as these are the most common interactions and he/she may need to make changes or monitor you more closely:

  • Warfarin
  • antacids calcium cholestyramine and iron supplements: (avoid taking at the same time should be separated by at least four hours)
  • rifampin

This is not a complete list of drug interactions. Ask your doctor or pharmacist to review your list of medications.

Other Information

Onset of effect: It may take a few weeks before the drug starts working you may not see any change in your symptoms until this time. You will likely get a blood test six weeks after the start of therapy and with any change of dose to make sure you are on the right dose.

Children: Dose will be adjusted depending on age and weight.

Seniors: More sensitive to side effects. Lower starting doses are required.

Pregnant women: Dose may need to be adjusted during and after pregnancy due to changes in hormones.

Women who are nursing: This drug passes into breast milk. Talk to your doctor.

People who drive or operate machinery: No special problems.

Alcohol: No known problems. If you drink always drink in moderation.

Overdose: if you seriously exceed the recommended dosage call your doctor or 911. A serious overdose may cause palpitations.

Stopping the drug: Do not stop taking this medication until you talk to your doctor. Symptoms will likely recur.

If you miss a dose: Take it as soon as you remember. If there are less than eight hours before you are supposed to take your next dose skip the upcoming dose and then return to your normal schedule.

Storage conditions: Closed container; cool dry location away from excess moisture (not in the bathroom) and light; always out of reach of children.

Dietary precautions: None