Aromatase Inhibitors Side Effects

Aromatase inhibitors are drugs, that lower the level of estrogen in the body, by inhibiting the action of the aromatase. Aromatase is an enzyme that is required for the biosynthesis of estrogen hormone. It helps the adrenal glands to convert androgen into estrogen and thereby, increases the level of estrogen in the body. These medications are mainly used in the treatment of breast cancer in post menopausal women. Aromatase inhibitors are however not very effective in reducing the level of estrogen in premenopausal women, as before menopause, estrogen synthesis is mainly carried out by the ovaries. Therefore, these medications are not used to treat breast and ovarian cancer in premenopausal women. Aromatase inhibitors are generally classified into two categories, namely, irreversible steroidal inhibitors and non steroidal inhibitors.

Aromatase Inhibitors for Breast Cancer Treatment
They can control the growth of malignant or cancerous cells of the breast, by inhibiting the conversion of androgen into estrogen. Generally, certain cells of the breast tissue contain estrogen receptors and the female hormone, estrogen binds with these receptors in order to stimulate the growth of the breast tissue. But, in case of breast cancer in postmenopausal women, binding of estrogen with these estrogen receptors found can contribute towards the rapid growth of the cancerous cells. Therefore, it becomes imperative to control the level of estrogen in the body in order to prevent the proliferation of the cancer cells.

In postmenopausal women, the ovaries stop the production of estrogen, but the hormone androgen is converted into estrogen by the adrenal glands with the help of aromatase. So, here aromatase inhibitors play an important role, as they inhibit the actions of the enzyme, aromatase and thereby, prevent the synthesis of estrogen. They are generally recommended after the initial cancer treatment like surgery, chemotherapy and radiation therapy. Sometimes, they are also used for treating breast cancer in the early stage. But, generally they are taken after using tamoxifen for 2 to 3 years. Tamoxifen is the drug that is commonly used in the treatment of breast cancer. It is believed that the possibility of recurrences of breast cancer in postmenopausal women reduces significantly, if they are taken for 5 years after taking tamoxifen for 5 years.

Aromatase Inhibitors Dangers
There are mainly three aromatase inhibitors that are widely used in the treatment of breast cancer in postmenopausal women. They are arimidex or anastrozole, aromasin or exemestane and femara or letrozole. Usually, the side effects of these medications are mild. As compared to side effects of tamoxifen, serious side effects are very less. One of the most common aromatase side effects is bone loss or osteoporosis, which can develop gradually due to prolonged use of these medications. Increased risk for osteoporosis can also lead to greater chances of having bone fractures.

Apart from these, some other common side effects are increase in joint pain or stiffness, and hypercholesterolemia. Joint pain and stiffness have been found to affect about 50% of women who take these medications. Hypercholesterolemia, on the other hand, is a condition characterized by the presence of excess cholesterol in the cells and blood plasma. This happens due to the reduction in the level of estrogen in the body. Such a condition can raise the risk of atherosclerosis, where the arteries become narrow due to deposition of fats inside the arterial wall. This in turn, may put an individual at a higher risk of developing heart or cardiovascular diseases. In addition to all these, some women can experience hot flushes, headaches, muscle aches and vaginal dryness after using them.

Considering the side effects, it is very important for the patients taking these medications to consult a physician, in order to regularly monitor their health conditions. The main risk of taking these drugs is bone thinning or osteoporosis, for which, bone mineral density should be monitored at regular intervals. Sometimes, to counteract the problem, physicians can recommend bone strengthening medicines. However, the bone thinning induced by these medications usually stop when their use is discontinued. But still, any kind of side effect related to drugs should always be reported to the physician, in order to figure out a plan for its effective management.