Know about Arimidex

Research Based
Medically reviewed by - Dr Rabia Akram, MD Written by - Dr. Deepakshi Chhabra


What is Arimidex ?

The drug with the generic name anastrozole is sold under the brand name Arimidex. It is an oral medication that is a member of the aromatase inhibitor drug subclass.1Overview| Researched based study from Since breast cancer cells depend on estrogen for growth, Arimidex is primarily used to treat hormone receptor-positive breast cancer in postmenopausal women.

The drug with the generic name anastrozole is sold under the brand name Arimidex. It is an oral medication that is a member of the aromatase inhibitor drug subclass.

How does Arimidex work?

Arimidex (anastrozole) functions by preventing the enzyme aromatase from converting specific hormones into estrogen.2Overview| Researched based study from In other words, aromatase inhibitors (AIs) reduce estrogen levels by blocking the action of the aromatase enzyme, which is found in adipose tissue, which converts other hormones into estrogen. This is crucial for the treatment of breast cancer that has hormone receptors because these cancer cells need estrogen to grow. Anastrozole, the medication’s active ingredient, does not work by increasing the body’s testosterone levels.


What is the primary use of Arimidex? 

Anastrozole, the active ingredient in Arimidex, has been primarily approved for the treatment of postmenopausal women with hormone receptor-positive breast cancer. There might be other off-label or research uses for Arimidex, though. It is significant to remember that off-label use must only be carried out with a healthcare provider’s approval and direction. Here is a list of a few applications for Arimidex:

  • As an Adjuvant therapy for cancer
  • Treats Gynecomastia
  • Preserves fertility
  • Treats Endometriosis
  • Manages precocious puberty
  • Helps in polycystic ovary syndrome treatment

Arimidex as adjuvant therapy

  • Postmenopausal women with early-stage hormone receptor-positive breast cancer can use Arimidex as adjuvant therapy (following surgery) to lower their risk of cancer recurrence3Uses| Researched based study from

Off-Label Uses

Arimidex may occasionally be utilized in situations that are not prescribed, such as: 

Gynecomastia treatment

  • Arimidex may be prescribed to treat estrogen-related side effects in people using anabolic steroids or undergoing hormone replacement therapy, such as gynecomastia (enlargement of breast tissue) or water retention.

Fertility preservation

  • Women with estrogen-sensitive cancers who need ovarian stimulation may use Arimidex off-label in some fertility preservation protocols.

Treatment of Endometriosis

  • Arimidex may occasionally be taken into account as a component of a patient’s overall treatment plan for endometriosis, a condition in which endometrial tissue protrudes from the uterus.

Precocious puberty management

  • Arimidex may be used outside of the recommended dosage to treat precocious puberty, a condition in which a child experiences puberty too early.

Treatment of PCOS

  • In some instances of polycystic ovary syndrome (PCOS), Arimidex may be used outside of the prescribed dosage to help lower estrogen levels and balance hormones.7Uses| Researched based study from

Investigational Uses

  • In numerous ongoing clinical trials, Arimidex is being examined for its potential to treat various cancers and other illnesses.


How is Arimidex incorporated into the overall treatment plan for breast cancer?

The following are some ways that Arimidex is used to treat breast cancer:

  • After primary treatments like surgery or radiation, there is adjuvant therapy, which halts the growth of hormone receptor-positive breast cancer cells, it lowers the risk of cancer recurrence.
  • Arimidex may also be used as the first line of therapy for breast cancer with early-stage hormone receptor positivity. Depending on the condition and stage one, it may be used individually or in conjunction with therapies such as chemotherapy.
  • The amount of time the treatment will continue completely depends on the situation surrounding the patient, such as the Stage of cancer, any risk factors associated, medicinal allergy, or reaction. This treatment takes years of consistent efforts for therapies and other medicinal intake, to get rid of the disease one is going through. 

What is the typical dosage of Arimidex? 

The following dosage for Arimidex is typically advised for the treatment of breast cancer:

  • Doctors and healthcare professionals recommend patients with a daily intake of 1mg of Arimidex medicine, administered orally.4Dosage| Researched based study from
  • Arimidex can be taken with or without food, as it does not affect its effectiveness, but it is necessary to take medicine every day at the same time to ensure the completion of the medication cycle. 

Side effects

What are the commonly documented side effects and adverse reactions with Arimidex?

The following side effects of Arimidex are the most frequently reported ones:

  • Hot flashes: A person may experience the sudden sensation of warmth that is frequently accompanied by sweating and flushing of the face and upper body.
  • Fatigue: While taking Arimidex, some people may feel more tired than usual, accompanied by severe headaches, and feelings of nausea.
  • Bone thinning or osteoporosis: Arimidex reduces estrogen production, which indirectly affects the bones, and sometimes excessive intake of Arimidex can decrease the bone mineral density causing bones to become soft and weaker, which increases the chance of fractures, especially of the hip, wrist, and spine.5Side effects| Researched based study from
  • Mood changes: Due to the reduction in the production of estrogen by Arimidex, the balance between the neurotransmitters which are responsible for mood regulation, disbalances, which cause anxiety and depression.
  • Vaginal dryness: Postmenopausal women taking Arimidex may experience vaginal dryness or discomfort. This happens because, a decrease in the levels of estrogen causes a reduction of vaginal secretions, which leads to dryness and itchiness around the sensitive area.
  • Allergy: One may find difficulty in breathing, or swelling of face muscles. This may happen due to any allergic reaction from the medicine.
  • Cardiovascular effects: Although the risk is typically low, Arimidex has been linked to a slightly elevated risk of cardiovascular events, such as heart disease and stroke.
  • Affects Liver: Arimidex has the potential to cause liver issues, majorly causing inflammation of the liver and in severe cases causing hepatitis and abnormalities in liver enzymes.5Side effects| Researched based study from
  • Weight increase: Estrogen which influence body metabolism, with the intake of Arimidex which lowers the estrogen levels, causes weight gain.
  • Blood clotting: Arimidex may increase the likelihood of Venous thromboembolism (VTE) blood clotting disorder, since Arimidex causes a lower percentage level of estrogen, which affects blood level and further leading to clotting. Such a kind of condition can be life threating, since the clot can travel the lungs which may block the blood flow.
  • Effect on Sexual Function: Arimidex’s effects on lowering estrogen can have an impact on sexual function, resulting in symptoms like decreased libido and dry vagina. Long-term use may result in these effects remaining. 


Does Arimidex interact with any other drugs?

The patient who is already on Arimidex should always consult the healthcare professional or the concerned doctor before taking any other medication including OTC, prescribed drugs, or healthcare supplements, since it can react with or delimit the effect of Arimidex. A few of them are explained below:

Estrogen containing drugs

  • It is not advised to take two medicated drugs that serve different purposes for the same organ or tissue. In other words, Arimidex which reduces estrogen levels, may not work as well if taken with estrogen-containing drugs like oral contraceptives. For example, Tamoxifen, a medication used to treat breast cancer, should not be taken with Arimidex because both have conflicting effects on estrogen. 

Other aromatase blockers

  • It is also not advised to use several aromatase inhibitors simultaneously. Letrozole and exemestane are two such aromatase inhibitors that may have effects that are comparable to those of Arimidex.

Drugs metabolized in liver

  • Since Arimidex is metabolized in the liver, drugs that do the same, like some antifungal drugs (like ketoconazole), should be used with caution, since it causes an increase in levels of Arimidex which can further lead to adverse side effects. 

Corticosteroids & SSRIs

  • Some drugs, like corticosteroids or selective serotonin reuptake inhibitors (SSRIs), could make patients more vulnerable to bone loss, which can be fatal in the future if these drugs are taken at the same time as Arimidex.


  • Apart from medicated drugs, the consumption of alcohol, or tobacco can also cause an interaction with the medicines, therefore medicine should not be used at that time.4Interactions| Researched based study from


Who should avoid using Arimidex?

Some people who should not use Arimidex (anastrozole) due to contraindications include the following:

Pre-menopausal Women

  • Arimidex is permitted for use in postmenopausal women, but it should not be used by pre-menopausal women who still have regular menstrual cycles, since it may disrupt the body’s normal hormonal balance.6Contraindications| Researched based study from

Pregnancy or breastfeeding

  • Arimidex shouldn’t be used during pregnancy or while breastfeeding the baby, since anastrozole may harm the fetus.6Contraindications| Researched based study from The medicine may mix with breast milk and can be fatal for the baby.

If hypersensitivity exists

  • If one is found to have any known hypersensitivity or allergy to anastrozole or any of the ingredients in it, they should avoid taking the medicine.

In estrogen-independent tumors

  • Arimidex is used specifically for estrogen-dependent hormone receptor-positive breast cancer. Consequently, it is not advised for people with estrogen-independent tumors.


  • Bodybuilders are not permitted to use or are not intended to use Arimidex (anastrozole). Bodybuilders use it as a Post Cycle Therapy because it inhibits the production of estrogen which lowers the elevated levels in men’s system that lead to gynecomastia. Such inhibitors are often misused or illegally obtained by some bodybuilders for use off-label.


What are the special safety measures to take into account when taking Arimidex?

There are certain safety measures one should consider before intake of Arimidex. They include:

  • Bone Health: Make frequent visit for consultation with your doctor regarding the bone health and heed their advice. Regular bone density exams, calcium and vitamin D supplements, weight-bearing exercises, and dietary changes could all contribute to this.
  • Liver Function: Because Arimidex is metabolized in the liver, people with impaired liver function should use this medication with caution. 
  • Heart and Vascular Health. When taking Arimidex, patients with pre-existing cardiovascular conditions should be closely watched.
  • Other Medications: Let your doctor know about all the drugs you are taking since any of them can react with Arimidex, which can adversely affect the hormones and the organs in the body.
Disclaimer: The user acknowledges that this article's information is being offered for informational purposes only. Every attempt has been made to guarantee that the article is informational and correct. If they have any doubts or questions about their health, we firmly advise our readers to visit a doctor or other healthcare professional.

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