Femara is also approved for the extended adjuvant treatment of early stage breast cancer in postmenopausal women who are within three months of completion of five years of tamoxifen therapy. The benefits of Femara in clinical trials are based on 24 months of treatment. Further follow-up will be needed to determine long-term results, including side effects.

In addition, Femara is approved for the treatment of postmenopausal women with estrogen receptor–positive or estrogen receptor–unknown breast cancer that has spread to another part of the body (metastatic cancer).

You should not take Femara if you are premenopausal. Your doctor should discuss the need for adequate birth control if you have the potential to become pregnant, if you are not sure of your postmenopausal status, or if you recently became postmenopausal. Femara is only indicated for postmenopausal women. Talk to your doctor if you're allergic to Femara or any of its ingredients. Femara should be used with caution by nursing mothers. You should not take Femara if you are pregnant as it may cause fetal harm. Some women reported fatigue and dizziness with Femara. Until you know how it affects you, use caution before driving or operating machinery. Some patients taking Femara had an increase in cholesterol. Additional follow-up is needed to determine the risk of bone fracture associated with long-term use of Femara.

In the adjuvant setting, commonly reported side effects are generally mild to moderate. Side effects that are comparable between Femara and tamoxifen include night sweats, weight gain, nausea and tiredness. Side effects seen more often with tamoxifen versus Femara were hot flashes and vaginal bleeding. Joint pain was experienced more often with Femara versus tamoxifen. The incidence of stroke was 1.1% for women on Femara and 1% for women on tamoxifen, and the incidence of other cardiovascular events was 6.6% for Femara versus 6.2% for tamoxifen. The percentage of women on Femara reporting bone fracture was 5.6% versus 4% for women on tamoxifen. The percentage of women reporting osteoporosis was 2% for Femara versus 1.1% for tamoxifen. Additional side effects for both Femara and tamoxifen are heart attack, thromboembolic events, endometrial cancer and second malignancies.

In the extended adjuvant setting, commonly reported side effects are generally mild to moderate. Those seen more often with Femara versus placebo were hot flashes (50% vs 43%), joint pain (22% vs 18%) and muscle pain (7% vs 5%). Other side effects, which were comparable to placebo, include fatigue (34% vs 32%), swelling due to fluid retention (18% vs 16%), headache (20% vs 20%), increase in sweating (24% vs 22%) and increase in cholesterol (16% vs 16%). The percentage of patients on Femara versus placebo reporting a fracture was 5.9% versus 5.5%. The percentage of patients reporting osteoporosis was 6.9% versus 5.5%. Bisphosphonates, drugs to increase bone strength, were given to 21.1% of Femara patients and 18.7% of placebo patients. Additional side effects seen in study are arthritis, dizziness, constipation, nausea and cardiovascular ischemic events.

In the metastatic cancer setting, commonly reported side effects are generally mild to moderate and may include bone pain, hot flashes, back pain, nausea, joint pain, shortness of breath, tiredness, coughing, constipation, limb pain, chest pain and headache.