Ashley asked
I want to take a Claritin in the morning for my allergies as it works well. However, I take levothyroxine and wanted to know if I could add Claritin to it.
Answer
There is no interaction between Claritin and levothyroxine. However, for optimal absorption and medication effects, levothyroxine should be taken as follows:
- Take levothyroxine first thing in the morning on an empty stomach, 30 to 60 minutes before breakfast, with a full glass of water.
- Do not like down for 30 minutes after taking levothyroxine to prevent esophageal irritation.
If you want to take Claritin every day for your allergies, it is important to take it at least 30 to 60 minutes after levothyroxine. Alternatively, you can take Claritin every day in the evening as the effects of the antihistamine will last around 24 hours.
Below, we list additional information about both medications.
Levothyroxine
Levothyroxine, which is available as the brand names Synthroid and Levoxyl, is a thyroid replacement medication for the treatment of hypothyroidism. Levothyroxine is the synthetic hormone, T4. T4 is converted in the body to more biologically active, T3.
Levothyroxine is well tolerated if dosed correctly and if side effects occur, it is often attributable to the wrong dosage. Too low of a dosage can manifest in symptoms of hypothyroidism such as:
- Fatigue
- Lethargy
- Chills
- Dry skin
- Poor memory
- Weight gain
Too high of a dosage can result in symptoms of hyperthyroidism, such as:
- Irritability
- Sweating
- Palpitations
- Tremors
- Diarrhea
- Weight loss
Claritin
Claritin (loratadine) is a second-generation antihistamine used to treat and prevent seasonal allergies.
Second-generation antihistamines, such as Claritin, are noted for their long duration of action, about 24 hours per dose, and lack of sedation side effects. In fact, Claritin is marketed as "non-drowsy" and the vast majority of individuals should not experience sedation when taking it.
After taking by mouth, Claritin begins working in about 60 minutes and generally lasts all day. Claritin can be taken every day for allergy symptoms and is very well tolerated, but may cause mild side effects such as nausea, dizziness and headache.
Summary
- There is no interaction between levothyroxine and Claritin (loratadine).
- However, levothyroxine should be taken by itself, first thing in the morning, about 30 to 60 minutes before other food or medications.
