Side Effects

Drug information provided by: Micromedex

Because of the way this medicine acts on the body, there is a chance that it might cause unwanted effects that may not occur until months or years after the medicine is used. Tamoxifen increases the chance of cancer of the uterus (womb) in some women taking it. Tamoxifen may cause blockages to form in a vein, lung, or brain. In women, tamoxifen may cause cancer or other problems of the uterus (womb). It also causes liver cancer in rats. In addition, tamoxifen has been reported to cause cataracts and other eye problems. Discuss these possible effects with your doctor.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common or rare

  1. Anxiety
  2. blistering, peeling, or loosening of the skin and mucous membranes
  3. blurred vision
  4. cataracts in the eyes or other eye problems
  5. change in vaginal discharge
  6. chest pain
  7. chills
  8. confusion
  9. cough
  10. dizziness
  11. fainting
  12. fast heartbeat
  13. fever
  14. hoarseness
  15. lightheadedness
  16. lower back or side pain
  17. pain or feeling of pressure in the pelvis
  18. pain or swelling in the legs
  19. pain, redness, or swelling in your arm or leg
  20. painful or difficult urination
  21. rapid shallow breathing
  22. shortness of breath or trouble with breathing
  23. skin rash or itching over the entire body
  24. sweating
  25. weakness or sleepiness
  26. wheezing
  27. vaginal bleeding
  28. yellow eyes or skin

Incidence not known

  1. Bloating
  2. constipation
  3. darkened urine
  4. diarrhea
  5. difficulty with breathing
  6. indigestion
  7. itching
  8. joint or muscle pain
  9. large, hard skin blisters
  10. large hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, and sex organs
  11. loss of appetite
  12. nausea
  13. pain in the stomach or side, possibly radiating to the back
  14. red, irritated eyes
  15. red skin lesions, often with a purple center
  16. sore throat
  17. sores, ulcers or white spots in the mouth or on the lips
  18. unusual tiredness or weakness
  19. vomiting

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  1. Absent, missed, or irregular periods
  2. decrease in the amount of urine
  3. feeling of warmth
  4. menstrual changes
  5. noisy, rattling breathing
  6. redness of the face, neck, arms and occasionally, upper chest
  7. skin changes
  8. stopping of menstrual bleeding
  9. swelling of the fingers, hands, feet, or lower legs
  10. troubled breathing at rest
  11. weight gain or loss
  12. white or brownish vaginal discharge

Less common or rare

  1. Abdominal or stomach cramps
  2. black, tarry stools
  3. bleeding gums
  4. blood in the urine or stools
  5. bluish color changes in skin color
  6. bone pain
  7. decreased interest in sexual intercourse
  8. discouragement
  9. feeling sad or empty
  10. hair loss or thinning of the hair
  11. headache
  12. inability to have or keep an erection
  13. irritability
  14. itching in the genital area
  15. loss of interest or pleasure
  16. loss in sexual ability, desire, drive, or performance
  17. nausea or vomiting (mild)
  18. pain
  19. pinpoint red spots on the skin
  20. skin rash or dryness
  21. stomach or pelvic discomfort, aching, or heaviness
  22. swelling
  23. trouble concentrating
  24. trouble with sleeping
  25. unusual bleeding or bruising

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.