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 Anastrozole  (Arimidex)

 Brand name: Arimidex  

Generic name: Anastrozole  

Therapeutic Class:  aromatase inhibitor  

Manufacturer / Distributor:  AstraZeneca 

Availability: Anastrozole is available by prescription only  

Anastrozole  (Arimidex)

Indications: Anastrozole is used to treat breast cancer in postmenopausal women, especially postmenopausal women in whom tamoxifen treatment is ineffective. 

Your doctor may use anastrozole to treat other medical conditions in addition to breast cancer. For instance, you can be prescribed Anastrozole as a preventive treatment if you are at risk for breast cancer.  

Dosage form: Anastrozole comes in tablet form to be taken by mouth, with or without food  

Dosage:  your doctor will determine the dose that is most effective to treat your medical condition. In general, he will consider your weight, other medical conditions you may have, and other drugs you are taking. However, anastrozole is often recommended at a dose of 1 mg per day. Take the medication around the same time every day, with or without food. Even if you feel better, it is important to take Anastrozole as recommended by your doctor or pharmacist. You may be recommended to take Anastrozole for several years; usually 5 years.   

Although Anastrozole can be taken with or without food, it is better to take anastrozole after a meal to reduce the risk of nausea or vomiting.  

Overdose: as Anastrozole is in pill form, overdose can occur during the treatment. In case you experience overdose symptoms, contact your doctor or a local poison control center near you immediately. They will do what is necessary to eliminate or reduce the symptoms and avoid serious complications.  

Missing dose: in case you forget to take Anastrozole at the recommended time, take the missed dose as soon as you remember it if it is not almost time for the next dose. In case it is time for the next dose, do not double it to recover the missing, it can be dangerous. Contact your doctor or wait to go back to your regular schedule.   

Contraindications/Precautions:   Anastrozole  is contraindicated, or should be used with precaution in the following conditions: 

  • children 
  • women who breastfeed 
  • pregnant women 
  • patients who are allergic to anastrozole or to one of its ingredients 
  • Pre-menopausal women.  

Before beginning treatment with Anastrozole, tell your doctor if you have any of these health problems:   

  • osteoporosis  
  • heart disease  
  • severe liver disease 
  • chronic renal failure 
  • Glucose and galactose malabsorption/intolerance. 

Mechanism of Action (MOA): Anastrozole works by inactivating the action of aromatase, an enzyme necessary for the conversion of androgen into estrogen. Once deactivated, aromatase is unable to provide estrogen to the growth and survival of breast cancer cells.  

Interactions: a combination of Anastrozole with tamoxifen and all treatments containing estrogens is not recommended. These substances can affect the action of Anastrozole in your body, and even cause serious health problems; talk to your doctor before taking any of the following:  

  • vitamin supplements  
  • herbal remedies, principally St. John Wort 
  • caffeine  
  • alcohol  
  • cigarette smoking 
  • Decongestants.  

Side effects: despite the beneficial effects of the drug, Anastrozole tends to cause adverse effects in most patients. Fortunately, these adverse effects tend to disappear when the body adjusts to the medication. The most common Anastrozole side effects include persistent or frequent need to urinate, breast pain, weakness, weight gain, headache, dry mouth, hair thinning/hair loss, hot flashes, sweating, nervousness, dizziness, decreased appetite, stomach pain, and heartburn, difficulty falling or staying asleep, nausea and vomiting, bowel disorders – constipation or diarrhea; joint, bone, or muscle pain; mood changes or/and depression; Feeling of burning or tingling in your hands or feet.

Although rare, Anastrozole can cause serious side effects which require immediate medical attention; contact your doctor immediately if you experience any of these symptoms:  

  • chest pain 
  • stomach pain  
  • swollen glands  
  • blurred vision 
  • shortness of breath 
  • difficulty swallowing or breathing 
  • yellowing of the skin or eyes (Jaundice) 
  • Skin problems: ulcers, itching, rash, blisters, hives, etc.  
  • vaginal problems such as bleeding, dryness, or irritation  
  • fever which can be accompanied by sore throat and cough 
  • Swelling of the eyes, face, lips, tongue, throat, arms, hands, feet, ankles, or lower legs. 


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