New report highlights aromatase inhibitor side effects

Intolerable side effects primary reason women discontinue use of aromatase inhibitors

Breast Cancer Action (BCA) released a report today, in conjunction with a poster presentation at the San Antonio Breast Cancer Symposium (Abstract #3131), on the side effects of aromatase inhibitors (AIs). The report, "Side Effects Revealed: Womenís Experiences with Aromatase Inhibitors," analyzes 612 womenís responses to an online survey of the drugsí side effects. (Call or e-mail for an embargoed copy of the report. After December 15, the full report and comments from survey respondents will be online at

Survey results show that nearly all respondents (96 percent) reported one or more side effects. Nearly 30 percent of the respondents reported discontinuing the use of an AI--84 percent because of intolerable side effects and close to half of them (47 percent) due to joint-related problems. The side effects reported by more than half of the survey respondents were: hot flashes, bone pain, feeling tired, muscle pain, and insomnia. Many respondents also reported experiencing joint-related side effects, vaginal atrophy and dryness, a rise in cholesterol levels, and general pain.

More than a quarter of respondents (37 percent) reported receiving no information from their doctors about short-term side effects. Over half (63 percent) reported receiving no information from their doctors about long-term effects, but because AIs are relatively new, little long-term side effect data is available.

"The results of the survey clearly indicate that patients deciding whether or not to take these drugs need to be fully informed about the side effects and whether the use of an AI is actually appropriate for them," said Marilyn Zivian, Ph.D., lead author of the report. "Itís very apparent that some of the women who responded to the survey are really suffering."

"Patients know about side effects before their doctors do--they experience them firsthand," said Barbara Brenner, executive director of BCA. "Now that hundreds of women taking aromatase inhibitors have spoken, itís time for the medical research community to respond with additional research on the side effects of these drugs." Brenner and Zivian are both women living with breast cancer.

BCA launched the online survey in August 2005 to collect data on the side effects of this new class of breast cancer treatment drugs. The organizationís goals in providing the results are to enable patients to make better treatment decisions, doctors to make more informed recommendations, and the FDA to monitor AI side effects.


Barbara Brenner and Marilyn Zivian are available for further comment. To schedule an interview please contact Rebecca Farmer of BCA at 415.243.9301, ext. 16.

BCA is a national grassroots education and advocacy organization. As a matter of policy, the organization does not accept any funds from pharmaceutical companies.

Last reviewed: By John M. Grohol, Psy.D. on 30 Apr 2016
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