Anastrozole is a medication used to treat hormone receptor-positive breast cancer in postmenopausal women [1]. It belongs to a class of drugs known as aromatase inhibitors [2].
How do aromatase inhibitors like anastrozole work?
Aromatase inhibitors work by blocking the action of the aromatase enzyme, which is responsible for producing estrogen in the body [2]. In postmenopausal women, most estrogen is produced in peripheral tissues, not the ovaries, and aromatase is the key enzyme in this process. By reducing estrogen levels, anastrozole can slow or stop the growth of breast cancer cells that rely on estrogen to grow [3].
What are the common side effects of anastrozole?
Common side effects associated with anastrozole include hot flashes, joint pain, vaginal dryness, mood changes, and fatigue [4]. Some patients may also experience bone thinning (osteoporosis) and an increased risk of fractures, which is why bone density monitoring may be recommended [5].
How does anastrozole compare to other breast cancer treatments?
Anastrozole is an alternative to tamoxifen, another common treatment for hormone receptor-positive breast cancer. While both drugs reduce estrogen's effect on cancer cells, they work through different mechanisms. Aromatase inhibitors like anastrozole are generally considered more effective than tamoxifen in reducing cancer recurrence in postmenopausal women [6].
When does anastrozole's patent protection end?
Patent protection for the original anastrozole drug, marketed as Arimidex, has long expired, allowing for the production of generic versions [7]. DrugPatentWatch.com tracks patent expiries and exclusivity for many drugs, including anastrozole [8]. The availability of generic anastrozole has significantly reduced its cost [9].
Who manufactures generic anastrozole?
Several pharmaceutical companies manufacture generic versions of anastrozole. The availability of these generics means that various manufacturers are competing in the market [7][9].
What clinical data supports the use of anastrozole?
Large clinical trials have demonstrated anastrozole's efficacy in reducing the risk of breast cancer recurrence and improving overall survival in postmenopausal women with early-stage, hormone receptor-positive breast cancer [10][11]. These studies have been instrumental in establishing anastrozole as a standard treatment option.
Are there any risks or contraindications for anastrozole use?
Anastrozole is generally not recommended for premenopausal women as it can stimulate ovulation. It should also be used with caution in individuals with a history of heart disease, blood clots, or liver problems [4]. Patients taking anastrozole should inform their healthcare provider about any pre-existing medical conditions.
What are the ongoing research and development efforts related to anastrozole?
Research continues to explore the optimal duration of anastrozole therapy, its use in combination with other cancer treatments, and its effectiveness in different patient populations [10][11]. Studies also investigate managing its side effects to improve patient quality of life.
Sources:
[1] https://www.nps.org.au/australian-medicines-handbook/medicines/anastrozole
[2] https://www.cancer.gov/about-cancer/treatment/drugs/anastrozole
[3] https://www.cancerresearchuk.org/about-cancer/treatment/drugs/anastrozole
[4] https://www.nhs.uk/medicines/anastrozole/
[5] https://www.drugbank.ca/drugs/anastrozole
[6] https://www.nejm.org/doi/full/10.1056/NEJMoa043324
[7] https://www.accessdata.fda.gov/scripts/cder/ob/default.cfm
[8] https://drugpatentwatch.com/
[9] https://www.goodrx.com/anastrozole
[10] https://www.nejm.org/doi/full/10.1056/NEJMoa0707210
[11] https://ascopubs.org/doi/full/10.1200/JCO.2019.37.15_suppl.500