Chemocare.com
Care During Chemotherapy and Beyond

Letrozole

(LET roe zole)

Trade Name: Femara®

Femara is the trade name for the generic drug letrozole.  In some cases, health care professionals may use the trade name  Femara ® when referring to the generic drug name letrozole.

Drug Type:

Letrozole is a hormone therapy. Letrozole is classified as an aromatase inhibitor.  (For more detail, see "How Letrozole Works" section below).

What Letrozole Is Used For:

  • Letrozole is used to treat breast cancer in postmenopausal women.

Note: If a drug has been approved for one use, physicians may elect to use this same drug for other problems if they believe it may be helpful.

How Letrozole Is Given:

  • Letrozole is a pill, taken by mouth.
  • You should take Letrozole at about the same time each day.  You may take Letrozole with or without food. If you miss a dose, do not take a double dose the next day.
  • You should not stop taking Letrozole without discussing with your physician.
  • The amount of Letrozole that you will receive depends on many factors, including your general health or other health problems, and the type of cancer or condition being treated.  Your doctor will determine your dose and how long you will be taking Letrozole.

Side Effects:

Important things to remember about the side effects of Letrozole:

  • Most people do not experience all of the side effects listed.
  • Side effects are often predictable in terms of their onset and duration. 
  • Side effects are almost always reversible and will go away after treatment is complete.
  • There are many options to help minimize or prevent side effects.
  • There is no relationship between the presence or severity of side effects and the effectiveness of the medication.

The following side effects are common (occurring in greater than 30%) for patients taking Letrozole:

These side effects are less common side effects (occurring in about 10-29%) of patients receiving Letrozole:

Not all side effects are listed above. Some that are rare (occurring in less than 10% of patients) are not listed here.  However, you should always inform your health care provider if you experience any unusual symptoms.

When to contact your doctor or health care provider:

The following symptoms require medical attention, but are not an emergency.  Contact your health care provider within 24 hours of noticing any of the following:

  • Symptoms of recurrent period (vaginal bleeding/spotting)

Always inform your health care provider if you experience any unusual symptoms.

Precautions:

  • Before starting Letrozole treatment, make sure you tell your doctor about any other medications you are taking (including prescription, over-the-counter, vitamins, herbal remedies, etc.).  
  • Inform your health care professional if you are pregnant or may be pregnant prior to starting this treatment. Pregnancy category D (Letrozole may be hazardous to the fetus.  Women who are pregnant or become pregnant must be advised of the potential hazard to the fetus).
  • Letrozole is indicated for post-menopausal women. Do not conceive a child (get pregnant) while taking Letrozole. Barrier methods of contraception, such as condoms, are recommended. Discuss with your doctor when you may safely become pregnant or conceive a child after therapy.
  • Do not breast feed while taking Letrozole.

Self-Care Tips:

  • If you are experiencing hot flashes, wearing light clothing, staying in a cool environment, and putting cool cloths on your head may reduce symptoms. Consult your health care provider if these worsen, or become intolerable.
  • Acetaminophen or ibuprofen may help relieve discomfort from generalized aches and pains.  However, be sure to talk with your doctor before taking it.
  • Letrozole causes little nausea.  But if you should experience nausea, take anti-nausea medications as prescribed by your doctor, and eat small frequent meals.  Sucking on lozenges and chewing gum may also help. 
  • Avoid sun exposure.  Wear SPF 15 (or higher) sunblock and protective clothing.
  • In general, drinking alcoholic beverages should be kept to a minimum or avoided completely.  You should discuss this with your doctor.
  • Get plenty of rest. 
  • Maintain good nutrition.
  • If you experience symptoms or side effects, be sure to discuss them with your health care team.  They can prescribe medications and/or offer other suggestions that are effective in managing such problems.

Monitoring and Testing:

You will be monitored regularly by your doctor while you are taking letrozole, but no special tests or blood tests are required.

How Letrozole Works:

Hormones are chemical substances that are produced by glands in the body, which enter the bloodstream and cause effects in other tissues.  For example, the hormone testosterone made in the testicles and is responsible for male characteristics such as deepening voice and increased body hair.  The use of hormone therapy to treat cancer is based on the observation that receptors for specific hormones that are needed for cell growth are on the surface of some tumor cells.  Hormone therapies work by stopping the production of a certain hormone, blocking hormone receptors, or substituting chemically similar agents for the active hormone, which cannot be used by the tumor cell.  The different types of hormone therapies are categorized by their function and/or the type of hormone that is affected.

Letrozole is an aromatase inhibitor.  This means it blocks the enzyme aromatase (found in the body's muscle, skin, breast and fat), which is used to convert androgens (hormones produced by the adrenal glands) into estrogen. In the absence of estrogen, tumors dependent on this hormone for growth will shrink.

Note:  We strongly encourage you to talk with your health care professional about your specific medical condition and treatments. The information contained in this website is meant to be helpful and educational, but is not a substitute for medical advice.  

Update 8/29/2012

Chemocare.com is designed to provide the latest information about chemotherapy to patients and their families, caregivers and friends. For information about the 4th Angel Mentoring Program visit www.4thangel.org