Why do you take Claritin with Neulasta?
The reason why Claritin (loratadine) is taken with Neulasta (pegfilgrastim) is to reduce bone pain, which is a very common side effect of Neulasta.

When patients are undergoing chemotherapy it often causes a decrease in neutrophils levels (which is a type of white blood cell that fights infection) and this increases the risk of infections.
Neulasta can be taken to increase the neutrophil levels but very commonly causes body pain.

How does Claritin help bone pain from Neulasta?

• It is thought that some of the bone pain that is caused by Neulasta is due to the effect Neulasta has on histamine, which induces inflammation and swelling in the bone marrow and results in pain.
• Claritin is an antihistamine that blocks histamine, so decreases the amount of inflammation and swelling in the bone marrow and therefore reduces the pain.

Does Claritin work for bone pain from Neulasta?

Different studies have shown different results, some studies show Claritin has no or minimal reduction on bone pain and a study using two antihistamines (one of them was Claritin) concluded that they did reduce bone pain from Neulasta

• In one clinical trial called published in 2016 the conclusion was that loratadine did not change severe bone pain or improve quality of life for patients on Neulasta.
• The NOLAN trial published in 2017 showed that there was a 5% decrease in patients who reported bone pain in the group treated with loratadine compared to the group that took placebo tablets, but this was considered not to be significant. The NOLAN trial conclusion was that loratadine could potentially reduce Neulasta associated pain.
• Another study looking at antihistamines to reduce pain caused by Neulasta used two antihistamines as a double antihistamine block. In this small study they used both famotidine and loratadine which they concluded was an inexpensive, safe and effective way to reduce bone pain.

Although Claritin (loratadine) has a minimal effect on pain it is well tolerated, inexpensive and easily administered so may be considered to help reduce bone pain in Neulasta patients.

When do you take Claritin (loratadine) to help with bone pain from Neulasta?

The loratadine dose to prevent bone pain from Neulasta in the NOLAN clinical trial was

• 1 loratadine 10mg tablet daily, in the morning for 5 days, starting on the day Neulasta is given.

Bottom line:

• Bone pain is a very common side effect of Neulasta.
• Clinical studies on Claritin to reduce bone pain from Neulasta show minimal reduction in pain.
• Due to loratadine being a well tolerated, inexpensive and easily administered medicine it may be considered for patients on Neulasta to reduce bone pain.