The use of Nolvadex in the treatment of generic Tamoxifen-associated small joint arthralgia.

INTRODUCTION

Small joint arthralgia has been anecdotally reported for many years by women taking generic Tamoxifen (gT). However, it is a symptom that is absent from the side effect profile of the original Tamoxifen preparation Nolvadex. Our aim was to determine the prevalence of arthralgia in Tamoxifen users and to investigate whether it was associated with the excipient profile of the newer, generic formulations of Tamoxifen.

METHODS

Women diagnosed with oestrogen receptor positive breast cancer between 2001 and 2005 were eligible. Those with new-onset arthralgia following commencement of gT were entered into a one year double crossover study. Patients were swapped from gT to Nolvadex for 6 months, the response noted, and then swapped back to gT for 6 months.

RESULTS

Of 1020 new breast cancer patients, 918 (90%) were oestrogen receptor (OR) positive and were started on gT as part of their treatment. Of those, a total of 121 (13.2%) suffered with arthralgia. All 121 patients agreed to enter the study and swap treatment to Nolvadex for 6 months 114 patients (94.2%) had resolution of their arthralgia whilst on Nolvadex (p < 0.05).

CONCLUSION

Our findings suggest that there is an arthralgia syndrome which is prevalent in women taking generic Tamoxifen preparations. Symptoms are abolished when Nolvadex is used instead of gT. This suggests that the excipient profiles are an important factor. We hypothesise that either the excipient profile of gT induces arthralgia, or an unknown excipient of Nolvadex has a protective effect.