Anastrozole (Oral)

Anastrozole is an oral medication that is used primarily in the treatment of breast cancer and is known by the brand name Arimidex.


Anastrozole is a non-steroidal drug which is shown to be effective in the treatment of breast cancer. There is a higher incidence of drug interactions when undergoing therapy using anastrozole. It is important to speak with your doctor about the potential side effects associated with this drug. Tell your doctor about any medications you are currently taking, including vitamins and herbal supplements. If you alter your diet or medication, it is important that you discuss this with your doctor, because it may interfere with your therapy with anastrozole.

In some instances, your doctor may prescribe anastrozole to treat certain types of ovarian cancer. If you have any health issues such as heart disease or kidney disorders, you should discuss using this medication with your doctor because it may pose additional risks to your health. Your doctor may need to modify your dose based on your medical history. In some cases, you may not be a good candidate for this treatment because of health conditions. This medication is not intended for use in individuals who are under the age of 18.

This therapy is effective for people who have all stages of breast cancer, including metastasized cancer in all stages. It is especially beneficial for patients who are in their postmenopausal stages.

You should not operate a vehicle when using anastrozole because it has a high incidence of making the user experience dizziness. Limit your consumption of alcohol when taking this medication, because it could intensify the side effects of the medication, as well as increase your chances of experiencing a crash when operating a vehicle or heavy machinery.

Conditions Treated

Type of medicine

  • Non-steroidal aromatase inhibitor

Side effects

Hot flashes

Hot flashes are a common side effect of this medication. If this problem persists longer than the first few weeks of treatment with this medication, you should inform your doctor.


You may experience a headache when using this treatment. If the headaches persist or become worse over the course of time, you should alert your doctor so they can change your course of treatment.

Trouble sleeping

Many patients experience trouble sleeping with anastrozole, especially during the adjustment period. Consult your doctor because they may be able to prescribe a medication to help you sleep while taking this medication.


Dizziness is the most common side effect of using anastrozole. To minimize this side effect, you should limit alcohol consumption. If the problem persists or gets worse, you should discuss a new treatment plan with your doctor or healthcare professional.

Stomach upset

If you experience stomach upset as a side effect of this medication, you should ensure that you take it with food, and you may consult your doctor about taking a medication to help with this issue. Consult your doctor before taking any medication to treat this side effect, even if it is an over the counter medication.


Vomiting as a side effect will normally be experienced in conjunction with an upset stomach. If the vomiting is frequent or severe you should alert your doctor immediately, because it may be a sign of an allergic reaction or some type of serious reaction. If the vomiting is occasional, you may be able to get a prescription for a medication to help from your doctor or healthcare provider.


Nausea is common, but if severe vomiting occurs, you should alert your doctor or healthcare professional immediately. You may need to change your course of treatment or have your dose changed. Nausea alone may not be life-threatening, but it could be a sign of a more serious underlying issue, or possibly an allergic reaction.


You may experience diarrhea when taking this medication. If the symptoms continue for an extended period of time or are accompanied by other persistent symptoms, you should alert your doctor. Always take this medication with plenty of water to help combat this side effect.


Make sure you drink plenty of water when taking anastrozole to help prevent constipation. If you become constipated, you should ask your doctor what medications you can take to alleviate the symptoms. If you fail to have a bowel movement after several days, you should seek medical assistance. Eating a healthy diet is also another way to help prevent this side effect when taking anastrozole.

Weight gain

Many find that weight gain is a common side effect of this medication. Eat a healthy diet and exercise regularly to help control the side effects, including weight gain. Ask your health care professional about beneficial foods you can eat to help keep your weight gain to a minimum.

Loss of appetite

Loss of appetite is most common during the first few weeks of the adjustment period. Consult with your doctor regarding ways to help keep weight on in the event you develop this common side effect.

Weakness or tiredness

Tiredness is a common side effect. Ensure that you get a full night's rest in order to keep this side effect to a minimum. If you begin to experience unusual weakness or a sudden onset, or even weakness in one side of the body, you should seek emergency assistance because it could be the indication of a life-threatening situation.


Coughing can be a moderate side effect when taking anastrozole. If the coughing persists for longer than a couple of weeks, you should tell your doctor because it could be a symptom of a more serious underlying complication associated with your illness.

Sore throat

You may experience a sore throat with this medication. Tell your doctor if it persists or is accompanied by a persistent cough. You may be able to obtain a prescription to help alleviate this side effect.

Anastrozole is an oral medication that is used primarily in the treatment of breast cancer and is known by the brand name Arimidex.


The general dose for an individual that has no special circumstances is 1 mg. In most cases, this is the dose given throughout the course of the treatment. The treatment is followed until the progression of of the tumor and is used during the early treatment phase, as a first-line treatment for patients who are postmenopausal. It can also be used locally for metastatic breast cancer and as a second line of treatment for the most advanced breast cancer that is following therapy including tamoxifen.

No renal adjustments are necessary or for issues concerning the liver. This medication is not intended for use in patients who are under the age of 18. If you begin to experience any side effects from this medication, you may want to talk with your doctor about altering your prescribed dose or changing your medication. If you have any questions about the dose you are taking you should ask your doctor and also read the pamphlet that is given to you by your doctor regarding the medication.


Anastrozole is known to have one major drug interaction and 40 moderate drug interactions.

Major drug interaction (1)


The use of thalidomide and anastrozole can result in blood clots that pose a threat to your life. The odds of developing these blood clots increases significantly if you have high cholestoral, high blood pressure, or smoke. If you take these medications together, you will need close monitoring by your doctor and will likely need to take a blood thinner to prevent the occurence of these blood clots. If you develop sudden loss of vision, difficulty breathing, coughing up blood, redness or swelling in the arms or the legs, chest pain, or shortness of breath, you should proceed to the emergency room and alert your doctor because these symptoms could indicate a life-threatening situation.

There is also one moderately hazardous lifestyle interaction with this drug.

Moderate drug interactions (40)

  • Activella
  • Adygyn
  • Aerodiol
  • Afirmelle
  • Alesse, alesse 21, alesse 28
  • Alora
  • Altavera
  • Alyacen
  • Amabel
  • Amethia
  • Amehtia Lo
  • Amethyst
  • Angeliq
  • Apri
  • Aquest
  • Aranelle
  • Ashlyna
  • Aubra
  • Aurovela 1.5, 1, 24 Fe, Fe 1.5, Fe 1
  • Aviane
  • Ayuna
  • Azurette

There are four disease interactions associated with anastrozole.


There was an increased incidence of cardiovascular events in women who had pre-existing conditions when taking this medication. Use caution when taking this medication if you have a cardiovascular complication.


Anastrozole may raise your cholesterol levels. If you have high cholesterol you should discuss this with your doctor and monitor your condition carefully during your treatment.

Hepatic dysfunction

If you have hepatic dysfunction, your toxicity should be monitored carefully during your treatment. This medication is metabolized extensively in the liver.


In patients with osteoporosis, there was a decrease in hip and lumbar spine bone density when it was compared with the baseline. Bone density should be monitored carefully in patients with osteoporosis.


Do not suddenly stop taking this medication without consulting your doctor first. To do so may result in life-threatening complications. Do not take this medication if you consume excessive amounts of alcohol. If you do drink alcohol you should consult your physician first to determine if this is going to be a potential threat to your health.

If you have any pre-existing conditions, you should discuss them with your doctor before beginning therapy with anastrozole. This drug may interact with certain diseases such as renal disease or pancreatic diseases. Do not give anastrozole to anyone under the age of 18 without doctor's approval. Monitor yourself for side effects and report any changes to your doctor or healthcare provider. If you feel you are having life threating side effects from this medication, you should immediately go to the emergency room and alert your doctor.

Do not take more than one dose of your medication at one time. If you skip a dose and it is time for your next dose, you should only take a single dose. Only take the medication once per day unless specifically directed by your doctor.


This medication should be stored out of the reach of children, others, and pets. You should store anastrozole out of direct sunlight and away from heat. Do not store in areas where this medication will be exposed to moisture such as the bathroom. Do not consume this medication past the expiration date. If the medication has expired, you should talk to your doctor about refilling your prescription.

Do not dispose of this medication in the toilet. If you have a community take-back program you should use their services to dispose of this medication. Consult the FDA's pamphlet regarding drug disposal if you do not have a community take-back program in your area. Keep anastrozole in a childproof container and always ensure you lock the cap before storing this medication. Don't leave your medication where it can be obtained easily by others.


Anastrozole is a non-steroidal aromatase inhibitor which is used primarily in the treatment of a variety of cancers such as breast cancer and ovarian cancer. It is particularly helpful for combating cancer in women because it suppresses the production of estrogen, which is thought to encourage the progression of the disease. It is used to prevent spreading and control the symptoms associated with cancer in postmenopausal women.

Anastrozole may increase the chances of medical complications in patients with pre-existing conditions. If you have a pre-existing condition and take medication to help control your symptoms, you should tell your doctor so they can tailor a treatment that works best for you individual needs.

Only take anastrozole once per day as directed by your doctor. If you miss a dose take it as soon as your remember. If it is time for your next dose, don't double your dose, but rather take the medication as scheduled and resume your course of treatment as directed.

Last Reviewed:
December 24, 2017
Last Updated:
April 04, 2018
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