Many women take medicines for about 5 years to help keep the cancer from coming back (although this time frame may change in the future).  The medicines are used if the breast cancer cells were “estrogen hormone receptor positive”.  The medicine is usually a pill that is taken one time a day.  Because it is a pill, you may not feel that it is very important to your continued good health.  Some recent studies show that these medicines increase the amount of women who survive disease free for five years by as much as 40%.  As with the treatment that you have already had, there are risks and benefits with these medicines.  The four most common medicines in this group are:

  • Tamoxifen (an older medicine that is used for women who have not gone through menopause, or older women who do not tolerate the other medications)
  • Arimidex, Aromasin, and Femara (these medications are newer and called aromatase inhibitors. These medications are only used in women who have gone through menopause)

How they work
Many breast cancers need estrogen to grow.  The drugs listed above all work by keeping the normal estrogen in the body from aiding in tumor growth.  They have been shown to greatly improve outcomes.  There are some risks and side effects with each drug.  You may not have any of them, or you may have several.  Every woman is different in her response to these drugs.

Common Risks and Side Effects

  • Hot flashes and sweats
  • Fatigue
  • Headaches
  • Nausea, indigestion, or diarrhea
  • Muscle aches or joint pain
  • Hair thinning
  • Risk of osteoporosis
  • Vaginal dryness
  • A general “not feeling very good”

One of the more common complaints by women who take these drugs is joint, muscle and/or bone pain.  If this is a problem, you should contact your doctor.  You may need to have some tests to see whether or not the pain is related to the medicine.  If the pain is from the medicine, there are a number of things that can be tried.

Some of them are:

  • Try over the counter medicine for pain and inflammation, like Tylenol or Ibuprophen.  Always talk with your doctor before trying these for relief.
  • Think about prescription medications for pain and inflammation.  These should be prescribed for you by your doctor.
  • Begin weight-bearing exercise.  Start this slowly after talking with your doctor about it.
  • Wear supportive shoes.
  • Do regular stretching and joint exercises.
  • Try using heat and massage in the area of pain, but do not use it on the area of your surgery or the arm on that side.

To decrease the bone related side effects of aromatase inhibitors (for women who have gone through menopause):

  • Take a Vitamin D 3 and Calcium supplement.
  • Do not smoke.
  • Limit alcohol to one drink per day.

Most of the above listed problems are mild.  There are other less common side effects that may be more serious.  If you are having problems taking your medicines or have concerns about taking these medications, talk with your doctor.  Think about the risks and the benefits as you talk.  DO NOT just stop taking the medicine because you are having a problem with side effects.  There are many things that can be done to help.  Some may involve changing your medicines or adding a new one to help with the side effects.  There may also be some non-drug treatments that may help.  Many of these problems get better after you have been taking the medicine for a while. BE SURE NOT TO STOP TAKING ANY MEDICATION WITHOUT TALKING TO YOUR DOCTOR.

Several of these medications are now available in a generic form and therefore are much less expensive (Tamoxifen is one of Wal-Mart’s $4 drugs). Talk with your physician and pharmacist about changing to the generic. Most women have been able to do this without any problem, and have not noticed any difference.

There are some rare, but serious side effects that you should be aware of like blood clots (Tamoxifen), jaw necrosis, and the development of other cancers.  Some symptoms that may go along with serious problems from taking these medicines need to be reported to your doctor and checked out as soon as possible.

Some of the serious problems may be:

  • Pain, redness or swelling in the lower leg.
  • Shortness of breath.
  • Chest pain.
  • Sudden severe headache.
  • Confusion.
  • Trouble speaking or moving.
  • Unusual female bleeding.
  • Jaw pain after major dental work.
  • Allergic reaction (rash, swelling-particularly of the face and mouth) should be reported


Other information
These medicines to prevent the return of cancer are usually taken one time a day.  It is best to take it at the same time each day.  It does not matter whether it is morning or evening.  These medicines should be:

  • Kept out of children’s reach.
  • Stored in the original container.
  • Kept at room temperature, away from moisture, direct heat and light.
  • If you are taken off the medicine by your doctor, return the rest of the medicine to the pharmacy, so they can be safely disposed of.
  • Refilled before you run out, so that you don’t miss a dose.
  • All other doctors (including dentists) should be told that you are taking this medication.

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