Arthralgia in 329 Patients Taking Aromatase Inhibitors

Arthralgia is common in post-menopausal women taking aromatase inhibitors. However, the underlying mechanism remains unknown.

We retrospectively examined the records of outpatients taking aromatase inhibitors to ascertain the frequency and severity of arthralgia.

Among 329 patients taking aromatase inhibitors (anastrozole in 239 and exemestane in 90 patients), 27% had arthralgia. There were 51 patients (16%) who switched from one aromatase inhibitor to another or quit aromatase inhibitor treatment. Arthralgia was the second most common reason for treatment changes in these 51 cases. In most cases, symptoms resolved after switching to a selective estrogen receptor modulator (SERM). We examined the relationships of arthralgia with other factors such as age, type of medication, prior treatments, and bone density. The arthralgia rate was significantly lower (p < 0.05) in patients with preceding endocrine therapy. No significant difference was detected between patients with versus patients without chemotherapy. Furthermore, there was no relationship between bone density and arthralgia.

Our observations suggest SERM treatment combined with an aromatase inhibitor to be perhaps the most practical clinical solution to the problem of arthralgia.