Q: I am taking Levothyroxin for thryoid. I need to take Claritin for allergies. Is it okay to do so without making the thryoid medicine less effective?
A: The prescribing information shows no significant interactions known or found for taking Levothyroxin (Synthroid, Levothroid) and Claritin (loratadine) at the same time. However, caution is always advised when taking multiple medications.
Q: What condition does levothroxine treat?
A: Levothyroxin is a replacement for a hormone that is normally produced by the thyroid gland to regulate the body's energy and metabolism. It is given when the thyroid does not produce enough of the hormone on its own. The medication is used to treat hypothyroidism (low thyroid hormone), and to prevent goiter (enlarged thyroid gland), which can be caused by hormone imbalances, radiation treatment, surgery, or cancer. It is given when a blood test shows a low thyroid level and symptoms may include becoming tired easily, becoming cold easily, weight gain, and depression. There is currently no way to correct the thyroid in the body when it cannot produce enough thyroid hormone, so the replacement is given, which works well, when the exact correct dose is found. There are many different doses and it is a potent hormone, so it is measured in micrograms. It takes 1000 micrograms to equal 1 milligram, which most medications are measured in. With so many doses available, the required amount can be "dialed" in very close to what each individual needs in their body. It usually takes the body approximately 6 weeks to have the final thyroid hormone dose produced, at which time a blood test is usually performed to make sure the body has the hormone in the correct range. The medication can bind up to food and some drugs, so it is recommended to be taken at least 30 minutes before a meal, or 2 hours after a meal. Many people find that it works well to take it first thing in the morning. If medications are added or subtracted to a daily regimen that interact with Levothyroxin, it can usually be adjusted to the proper level. Patti Brown, PharmD
Levothyroxin S >
Levothyroxin may cause side effects. Some common ones include:
- Weight loss
- Stomach cramps
- Excessive sweating
- Increased appetite
- Changes in menstrual cycle
- Sensitivity to heat
- Temporary hair loss, especially among children during the first month of treatment
More serious side effects can also occur. If you have any of these side effects, stop taking Levothyroxin and get medical treatment right away:
It's Equally Safe
Generic Levothyroxin is just as safe as the brand names—in the United States, these include Synthro > That sa > If you're not sure what your prescription's ingredients contain, ask your pharmacist for a list.
A study that was presented at the 2017 American Thyro >
The study found that after a year, both those who were taking generics and those who were taking brand names had the same risk for hospitalization due to cardiovascular effects such as heart attack, stroke, congestive heart failure, and atrial fibrillation, a type of heart arrhythmia.
Another notable point is that the majority of the patients, nearly 71%, were prescribed generic Levothyroxin, while just over 22% were prescribed brand names. The researchers also found that over 60% of the prescribers were primary care physicians, most of whom prescribed generics, while nearly 11% were endocrinologists who were significantly more likely to prescribe brand-name Levothyroxin.
Serious side effects
It happens rarely, but some people may have serious side effects when taking Levothyroxin.
Call a doctor straight away if you get:
- chest pain
- fast or irregular heartbeats, or palpitations