Anastrozole was the first of the third-generation aromatase inhibitors, becoming available for the second-line treatment of advanced breast cancer in 1995.

Aromatase belongs to the group of cytochrome P450 enzymes that are involved in steroid biosynthesis. It is found within peripheral tissues, including muscle, fat and liver, and within breast tumor cells. Aromatase is the final-step enzyme in oestrogen synthesis, converting the androgens androstenedione and testosterone to the oestrogens oestrone and oestradiol. Aromatase inhibitors work by blocking this converion, thus decreasing the availability of circulating oestrogen. The inhibition of oestrogen production is an effective therapy for women with hormone-dependent breast cancer. The aromatase inhibitors were developed for use in postmenopausal women, where oestrogen is synthesized predominantly by the peripheral conversion of the adrenal steroid androstenedione to oestrone. Anastrozole binds reversibly to the aromatase enzyme and is classed as a type II nonsteroidal aromatase inhibitor. In premenopausal women, the ovaries are the primary sites of oestrogen production. As the aromatase inhibitors are not able to completely block ovarian oestrogen synthesis, they cannot be used as the sole endocrine treatment in premenopausal patients. However, in this patient group, the aromatase inhibitors may be used in combination with agents that suppress ovarian function, such as goserelin, a gonadotrophin-releasing hormone agonist. However, there are only limited data to support this combination.

In men anastrozole stimulates the body to produce more of its own testosterone, the substance fools the body's negative feedback system, and cause an increase in the pituitary's release of luteinizing hormone (LH), which in turn stimulates the testicles to make more testosterone. The beauty of this is that the rise in testosterone comes entirely from increased production by the man's body itself. In concept, this is the most natural form of treatment.

Anastrozole is given at a clinical dose of 1 mg once daily. It has a half-life of 41 hours and it takes seven days to reach steady-state plasma levels.

Anastrozole is produced by many reputable pharmaceutical companies such as:
Arimixyl by Kalpa Pharmaceuticals
Anastrozol by Balkan Pharmaceuticals
Anastrozol 1 MG by Balkan Pharmaceuticals
Aridex by Gen-Shi Laboratories
Arimidex by Astra Zeneca
GP Anastrozole by Geneza Pharmaceuticals
Anastraol Tablets by Asia Pharma

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• Arimixyl

  Manufacturer: Kalpa Pharmaceuticals
  Substance: Anastrozole
  Pack: 30 tablets (1 mg/tab)

  
  

• Anastrozol

  Manufacturer: Balkan Pharmaceuticals
  Substance: Anastrozole
  Pack: 60 tabs (0.25mg/tab)

  
  

• Anastrozol 1 MG

  Manufacturer: Balkan Pharmaceuticals
  Substance: Anastrozole
  Pack: 60 tabs (0.25mg/tab)

  
  

• Aridex

  Manufacturer: Gen-Shi Laboratories
  Substance: Anastrozole
  Pack: 1 x 30 tabs (1 mg/tab)

  
  

• Arimidex

  Manufacturer: Astra Zeneca
  Substance: Anastrozole
  Pack: 28 tabs (1 mg/tab)

  
  

• GP Anastrozole

  Manufacturer: Geneza Pharmaceuticals
  Substance: Anastrozole
  Pack: 1 x 20 tabs (1 mg/tab)