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Anastrozole Side Effects

For the Consumer

Applies to anastrozole: oral tablet

In addition to its needed effects, some unwanted effects may be caused by anastrozole. In the event that any of these side effects do occur, they may require medical attention.

Severity: Major

You should check with your doctor immediately if any of these side effects occur when taking anastrozole:

More common:
  • Blurred vision
  • chest pain or discomfort
  • dizziness
  • headache
  • nervousness
  • pounding in the ears
  • shortness of breath
  • slow or fast heartbeat
  • swelling of the feet or lower legs
Less common:
  • Arm, back, or jaw pain
  • chest tightness or heaviness
  • cough or hoarseness
  • difficult or painful urination
  • dizziness, severe
  • fever or chills
  • headache, continuing
  • increased blood pressure
  • lower back or side pain
  • nausea
  • pain, tenderness, bluish color, or swelling of the foot or leg
  • sore throat
  • sudden shortness of breath
  • sweating
  • unusual tiredness or weakness
  • vaginal bleeding (unexpected and heavy)
Incidence not known:
  • Blistering, peeling, or loosening of the skin
  • hives
  • itching, puffiness, or swelling of the eyelids or around the eyes, face, lips, or tongue
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • red skin lesions, often with a purple center
  • sores, ulcers, or white spots in the mouth or on the lips
  • welts

Severity: Minor

Some of the side effects that can occur with anastrozole may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Acid or sour stomach
  • back pain
  • belching
  • body aches or pain
  • bone pain
  • congestion
  • constipation
  • decrease in height
  • diarrhea
  • dry mouth
  • dryness or soreness of the throat
  • feeling of warmth
  • fever
  • flushing or redness of the skin, especially on the face and neck
  • heartburn
  • hot flashes
  • increased appetite
  • indigestion
  • lack or loss of strength
  • loss of appetite
  • mood or mental changes
  • pain in the back, ribs, arms, or legs
  • pain, general
  • pelvic pain
  • runny nose
  • skin rash
  • stomach discomfort, upset, or pain
  • tender, swollen glands in the neck
  • trouble in swallowing
  • voice changes
  • vomiting
  • weakness
  • weight loss
Less common:
  • Anxiety and confusion
  • breast pain
  • chills
  • cough producing mucus
  • difficulty breathing
  • dryness of the vagina
  • general feeling of discomfort or illness
  • itching of the skin
  • joint pain and stiffness
  • loss of hair
  • muscle pain
  • numbness or tingling of the hands or feet
  • shivering
  • sleepiness or unusual drowsiness
  • trouble sleeping or sleeplessness
  • weight gain
  • wheezing

For Healthcare Professionals

Applies to anastrozole: compounding powder, oral tablet


Gastrointestinal side effects (up to 33%) have included nausea (up to 20%), vomiting (up to 11%), diarrhea (up to 8%), constipation (up to 8%), and abdominal pain (up to 8%).[Ref]


Other side effects have included headache (up to 18%), hot flushes (up to 13%), pain (up to 15%), and chest pain (up to 7%).[Ref]


General side effects have included asthenia (up to 16%).[Ref]


Musculoskeletal side effects have included arthritis (up to 17%), arthralgia (up to 15%), bone pain (up to 12%), osteoporosis (up to 11%), fracture (up to 10%), and back pain (up to 11%).

Postmarketing musculoskeletal side effects have included myalgia and trigger finger.[Ref]


Respiratory side effects have included dyspnea (up to 11%), pharyngitis (up to 9%), increased cough (up to 8%), and dry mouth (up to 6%).[Ref]


Cardiovascular side effects have included hypertension (up to 13%), edema (up to 11%), including peripheral edema (up to 9%). Ischemic cardiovascular disease (4%) has also been reported.[Ref]


Genitourinary side effects include pelvic pain (up to 7%).[Ref]


Dermatologic side effects have included rash (up to 11%) and alopecia. Henoch-Schonlein purpura has been reported. A case of subacute cutaneous lupus erythematosus has also been reported.

Postmarketing dermatologic side effects have included rash including mucocutaneous disorders such as erythema multiforme and Stevens-Johnson syndrome.[Ref]

Nervous system

Nervous system side effects have included insomnia (up to 10%), dizziness (up to 6%), paresthesia (up to 6%), and carpal tunnel syndrome.[Ref]


Psychiatric side effects have included depression (up to 5%).[Ref]


Hepatic side effects have been reported including a case of severe acute hepatitis in a patient treated with anastrozole.

Postmarketing hepatic side effects have included hepatitis, and increases in alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma-GT, and bilirubin.[Ref]


Hematologic side effects have included lymphedema (10%) and anemia (4%).


Metabolic side effects have included hypercholesterolemia (up to 9%).

Postmarketing metabolic side effects have included hypercalcemia (with or without an increase in parathyroid hormone).


Postmarketing hypersensitivity side effects have included allergic reactions including angioedema, urticaria, and anaphylaxis.


1. "Product Information. Arimidex (anastrozole)." Zeneca Pharmaceuticals, Wilmington, DE.

2. Higa GM, alKhouri N "Anastrozole: a selective aromatase inhibitor for the treatment of breast cancer." Am J Health Syst Pharm 55 (1998): 445-52

3. Pellegrini F, Rossi V, Fassone F, et al "Henoch-Schonlein purpura and aromatase inhibitors." Eur J Dermatol 19 (2009): 519-20

4. Trancart M, Cavailhes A, Balme B, Skowron F "Anastrozole-induced subacute cutaneous lupus erythematosus." Br J Dermatol 158 (2008): 628-9

5. de la Cruz L, Romero-Vazquez J, Jimenez-Saenz M, Padron JR, Herrerias-Gutierrez JM "Severe acute hepatitis in a patient treated with anastrozole." Lancet 369 (2007): 23-4

Not all side effects for anastrozole may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.