Arimidex

Anastrozole, with trade name Arimidex/AstraZeneca, is a drug prescribed for breast cancer after surgery and for metastases in post-menopausal women. An aromatase inhibitor, Anastrozole interrupts a critical step in the body's synthesis of estrogen. Some breast cancer cells require estrogen to grow, and eliminating estrogen suppresses their growth.

Its annual sales is approx $2.2bn. Patent expires 2010 in the US; the generic form is available in some other markets.

Medications and Prescriptions

Generic name: Anastrozole (Anastrozol)

Arimidex description:

Clinical trials

The experiment of ATAC (Arimidex, Tamoxifen, Alone or in Combination) shows an enduring follow-up study of 9366 women with localized breast cancer who received either anastrozole, tamoxifen, or both.

[1] It is proved that after more than 5 years the group that received anastrozole had significantly better clinical results than the tamoxifen group. The experiment proved that Anastrozole is the preferred medical therapy for postmenopausal women with localized breast cancer that is estrogen receptor (ER) positive.

According to studies, the risk of recurrence was reduced 40% (with some risk of bone fracture) and that ER negative patients also benefited from switching to Arimidex.

Mechanism of Action:

Through competitive inhibition, Anastrozole binds reversibly to the aromatase enzyme. This enzyme is responsible for converting androgens to estrogens. Elevated levels of estrogens may increase the severity of breast cancer, as sex hormones can cause hyperplasia and differentiation at estrogen receptor sites.

Side effects:

Bone weakness:

It is proved that women who changed to Arimidex (after two years on tamoxifen) reported twice as many fractures as those who continued to take tamoxifen (2.1% compared to 1%).

Sometimes Bisphosphonates are prescribed to prevent the osteoporosis stimulated by aromatase inhibitors. However, it has another serious side effect, osteonecrosis of the jaws. Statins have a bone strengthening effect; as such the statin combined with an aromatase inhibitor may avoid both fractures and possible cardiovascular risks without jaw osteonecrosis. In one study of women with breast cancer taking anastrozole, statin use was associated with a 38% reduced fracture risk or approximately the equivalent of 10 mg Fosamax daily.

Usage for men:

Though formally suggested for women, this drug has proven effective in the off-label use of reducing estrogens (in particular and more importantly, estradiol) in men. But, excess estradiol in men can cause benign prostatic hyperplasia, gynecomastia, and symptoms of hypogonadism. Anastrozole is used by some athletes and body builders as a part of their steroid cycle to reduce and prevent symptoms of excess estrogens; in particular, gynecomastia and water retention.

According to the reports, the dosages of 0.5 mg to 1 mg a day reduce serum estradiol by about 50% in men, which differs from the typical reduction in postmenopausal women. However the reduction may be different for men with grossly elevated estradiol (clinical data is currently lacking).

Usage for children:

In case of children, this drug is frequently used in the treatment for growth disorder to stop or slow the onset of puberty. The reason of the growth disorder is through hormones which may set off the early onset of puberty. The bone growth plates begin to close at the onset of puberty. This can occur in children as young as 5 years old, so for children severely behind in growth, the opportunity for increased growth is diminished. Arimidex is shown to slow or stop this process.

Things to remember about Arimidex tablets:

As Arimidex may work together with other medicine, inform your doctor about the medicines you are taking, including non-prescribed drugs such as complementary therapies and herbal drugs.

The tablets are to be kept in a safe place where children cannot reach them, as Arimidex could harm them. Arimidex tablets should be stored in the original packaging. Keep the tablets at room temperature away from direct heat and light. If your doctor decides to stop the treatment, return any remaining tablets to the pharmacist. You should not flush them down the toilet or throw them away. Tell your doctor or nurse, if you are sick just after taking the tablet, as you may need to take another one. Remember to get a new prescription a few weeks before you run out of tablets, and make sure that you have plenty for holidays.

Arimidex notes:

Arimidex, known with Generic name Anastrazole or Anostrazol, is a hormonal therapy treatment used for treating breast cancer in women who have passed their menopausal period. It is a type of hormone therapy that hampers with the production or action of some specific hormones in the body or the substances that are produced naturally in the body. Arimidex acts as chemical messengers and also helps in controlling the activity of cells and organs. Hormonal therapies are of different types. You will be guided doctor for the best hormonal therapy that suit your specific condition and provide you with arimidex patient assistance.

Arimidex acts as aromatase inhibitors which are drugs that block the process of the production of oestrogen that leads to the formation of breast cancer. This drug holds the process of aromatisation, thus reducing the production of oestrogen in the body.

Arimidex is an oral medication, consumed once a day whether in the morning or evening and has to be consumed just about the same time every day. Apart from treating breast cancer, it prevents the condition like advanced breast cancer or spreading of cancerous growth to other parts of the body. Arimidex is also used to treat early breast cancer in post-menopausal women. Its side effects can vary from person to person. Some of the rare side effects include hot flushes, sweats, tiredness, lethargy, joint pains or muscular stiffness in some, headaches, vaginal dryness, skin rashes nausea, vomiting and diarrhea. There is also a possibility for hair thinning and it can re-grow after the treatment ends. Sometimes, vaginal bleeding has also been reported. For men, Arimidex can help in reducing the change of testosterone and adrenal hormones to estrogen.