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Arimidex Side Effects

Generic Name: anastrozole

Note: This page contains information about the side effects of anastrozole. Some of the dosage forms included on this document may not apply to the brand name Arimidex.

For the Consumer

Applies to anastrozole: oral tablet

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

Major Side Effects

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

Minor Side Effects

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


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]


Very common (10% or more): Arthritis/arthralgia/arthrosis/joint disorder/joint pain/joint stiffness (36%), back pain (12%), bone pain (12%), osteoporosis (11%), fracture (10%)
Common (1% to 10%): Myalgia, anorexia
Uncommon (0.1% to 1%): Trigger finger[Ref]


Very common (10% or more): Nausea (20%), vomiting (11%)
Common (1% to 10%): Abdominal pain, diarrhea, constipation, dyspepsia, gastrointestinal disorder, dry mouth[Ref]


Very common (10% or more): Fatigue/asthenia (19%), pain (17%), accidental injury (10%), lymphedema (10%), peripheral edema (10%)
Common (1% to 10%): Infection, flu syndrome, cyst, fever, neck pain, malaise[Ref]


Very common (10% or more): Mood disturbances (19%), depression, insomnia[Ref]

Nervous system

Very common (10% or more): Headache (18%), depression (13%), insomnia (10%)
Common (1% to 10%): Dizziness, anxiety, paresthesia, hypertonia, cerebrovascular event (cerebrovascular accident, cerebral ischemia, cerebral infarct), somnolence, confusion, nervousness, carpal tunnel syndrome, sensory disturbances (e.g., taste loss and taste perversion)[Ref]


Very common (10% or more): Rash (11%)
Common (1% to 10%): Sweating, alopecia/hair thinning, pruritus
Rare (less than 0.1%): Skin reactions (lesions, ulcers blisters), erythema multiforme, cutaneous vasculitis (including Henoch-Schonlein purpura)
Very rare (less than 0.01%): Stevens-Johnson syndrome[Ref]


Very common (10% or more): Dyspnea (11%), increased cough (11%), pharyngitis (10%)
Common (1% to 10%): Sinusitis, bronchitis, rhinitis[Ref]


Common (1% to 10%): Urinary tract infection, breast pain, vulvovaginitis, vaginal hemorrhage, vaginitis, vaginal discharge, vaginal bleeding, vaginal dryness, pelvic pain, leukorrhea[Ref]


Common (1% to 10%): Anemia, leukopenia[Ref]


Common (1% to 10%): Increased gamma GT, increased SGOT, increased SGPT, increased alkaline phosphatase
Uncommon (0.1% to 1%): Hepatobiliary events (e.g., increased bilirubin), hepatitis
Rare (less than 0.1%): Changes in liver function (liver inflammation, liver pain, liver swelling)[Ref]


Common (1% to 10%): Weight gain, hypercholesterolemia, weight loss, anorexia
Uncommon (0.1% to 1%): Hypercalcemia (with or without an increase in parathyroid hormone)[Ref]


Common (1% to 10%): Allergic reactions
Uncommon (0.1% to 1%): Urticaria
Rare (less than 0.1%): Anaphylaxis, anaphylactoid reaction
Very rare (less than 0.01%): Angioedema[Ref]


Common (1% to 10%): Cataracts[Ref]


Common (1% to 10%): Neoplasm, tumor flare
Uncommon (0.1% to 1%): Endometrial cancer[Ref]


1. Cerner Multum, Inc. "Australian Product Information." O 0

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

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

Not all side effects for Arimidex 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.