Anastrozole

Anastrozole is an anticancer drug belonging to the class of aromatase inhibitors. Aromatase is an enzyme that plays a key role in the synthesis of estrogens (female sex hormones), therefore, anastrozole is used in the treatment of hormone-dependent tumors.

Anastrozole - Chemical Structure

Indications

For what it uses

The use of anastrozole is indicated for the treatment of breast cancer in post-menopausal women.

Warnings

Before taking anastrozole, you must tell your doctor if you fall into one of the following categories:

Pre-menopausal patients;
Patients taking tamoxifen (another anticancer medicine used to treat breast cancer);
Patients taking estrogen-containing drugs;
Patients with osteoporosis;
Patients suffering from liver and / or kidney diseases.

Anastrozole could cause side effects that can alter the ability to drive or use machines, so caution should be used.

For those who do sports, the use of the drug without therapeutic necessity is doping. The drug can cause positive doping tests even when used at therapeutic concentrations.

Interactions

Concomitant administration of tamoxifen and anastrozole should be avoided, as tamoxifen may reduce the therapeutic efficacy of anastrozole.

Anastrozole should not be administered simultaneously with estrogens, because they can cause a reduction in anastrozole activity itself.

You must inform your doctor if you are taking similar drugs of LH-RH (luteinizing hormone release factor), ie drugs that act to induce a pharmacological menopause. These include gonadorelin, leuprorelin, buserelin, goserelin, leuprorelin and triptorelin.

In any case, you must inform your doctor if you are taking - or have recently been taken - drugs of any kind, including over-the-counter drugs and herbal and / or homeopathic products.

Side effects

Anastrozole can induce various types of side effects. The type of adverse effects and the intensity with which they occur vary from individual to individual, depending on the sensitivity that each patient has towards the drug.

The following are the main side effects that may occur during anastrozole therapy.

Nervous system disorders

Treatment with anastrozole can cause headaches, weakness and drowsiness.

Hot flashes and sweating

Anastrozole therapy can cause hot flashes and increased sweating. These symptoms can be caused by the lack of estrogen in the body due to treatment with the drug. These side effects usually occur in mild form and disappear after some time. It may be helpful to reduce the consumption of tea, coffee, tobacco and alcohol.

However, if the symptoms appear severe and / or persist it is necessary to inform the oncologist that he will decide how to proceed.

Alopecia

Treatment with anastrozole can cause hair to fall out which can thin out or fall completely. This side effect, however, is temporary and the hair should begin to grow back soon after the end of therapy.

Hypercholesterolemia

Anastrozole therapy can cause an increase in blood cholesterol levels, therefore constant cholesterol monitoring is required for the duration of the chemotherapy.

Bone disorders

Reduction in bone mineral density may occur following treatment with anastrozole, which leads to an increased risk of bone fractures and / or an increased risk of developing osteoporosis.

Allergic reactions

Treatment with anastrozole may cause allergic reactions in sensitive individuals. These reactions can occur in the form of skin rashes or - in the most serious cases - in the form of swelling in the throat with consequent difficulty in swallowing and breathing.

Skin and subcutaneous tissue disorders

Following anastrozole therapy, rashes may occur, inflammation of the skin accompanied by red spots, blisters and hives.

Vascular pathologies

Treatment with anastrozole may favor the onset of Henoch- Schönlein purpura, a disease due to inflammation of small blood vessels - such as capillaries - characterized by the appearance of red or purple spots on the skin.

Gastrointestinal disorders

Anastrozole therapy can cause nausea, vomiting and diarrhea.

Vomiting can be controlled by using anti-emetic drugs.

Diarrhea can be controlled using antidiarrheal drugs. In any case, it is good to drink a lot in order to replenish lost fluids.

Reproductive system disorders

Treatment with anastrozole can cause vaginal dryness or vaginal bleeding. Generally, vaginal bleeding occurs in the first weeks of treatment, but if it persists, it is necessary to inform the oncologist.

Osteoarticular pains

Anastrozole therapy can cause bone pain, joint stiffness, joint pain and inflammation of the same (arthritis). The use of analgesic drugs may be useful, but it is still necessary to discuss them with your doctor first.

Liver disorders

Treatment with anastrozole can cause changes in blood tests to control liver function. For example, alterations may occur in the blood levels of gamma glutamyl transferase and in the blood levels of bilirubin.

Furthermore, the drug can promote the occurrence of hepatitis.

Other side effects

Other side effects that may occur following treatment with anastrozole are:

Loss of appetite;
Carpal tunnel syndrome, whose symptoms can be tingling, numbness and pain in some parts of the hand;
Muscular pain;
Snap fingers, or a disorder in which a finger of the hand takes a folded position and, subsequently, straightens up with a click;
Hypercalcemia (excessive increase in the concentration of calcium in the bloodstream) characterized by symptoms such as nausea, vomiting and increased thirst.

Overdose

If you suspect you have taken an overdose of anastrozole, you must contact a doctor immediately or contact the nearest hospital.

Action mechanism

Anastrozole is a non-steroidal aromatase inhibitor; it is a very powerful and highly selective compound.

Cancer cells that make up some forms of breast cancer need estrogen to grow.

In the pre-menopausal phase, estrogens are mainly produced in the ovaries.

In post-menopause, however, the ovaries lose their functional capacity, but estrogens continue to be synthesized - albeit in minimal quantities - in peripheral adipose tissues, such as those found in the breast. Estrogens are produced by conversion of androgenic hormones thanks to the action of the aromatase enzyme.

Anastrozole - by inhibiting this enzyme - is able to block the conversion of androgens into estrogens. In this way, the tumor cells are deprived of an element that is fundamental to them and are therefore condemned to certain death.

Mode of Use - Posology

Anastrozole is available for oral administration in the form of tablets.

The tablets should be swallowed whole - without chewing - with the help of a glass of water. The drug can be taken either near or away from meals. In any case, it is advisable to take anastrozole every day at the same time.

The dose of anastrozole must be established by the oncologist on an individual basis. Treatment with the drug is usually long-term and may even last a few years.

Pregnancy and breastfeeding

Anastrozole treatment should only be performed in postmenopausal women. Therefore, the use of the drug by pregnant women and by mothers who are breast-feeding should not be used.