Fluoxymesterone

What this drug is used for: 

Fluoxymesterone  is used  to treat breast cancer.   It is a palliative treatment for recurrent estrogen-receptor positive  breast cancer.

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 this drug is given:

• Fluoxymesterone is  a pill, taken  by mouth.

The amount of fluoxymesterone that you will receive depends  on many factors, including  your height  and weight, your general health  or other health problems, and the type of cancer or condition being treated.  Your doctor will determine your dose and schedule. 

Side effects: 

Important things  to remember about the side effects of fluoxymesterone: 

• 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 side effects of  fluoxymesterone and their severity depend on how much of the drug is given.  In other words, high doses may produce  more severe side effects. 

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

• Absence of menstrual periods (amenorrhea) (see menopause) 
• Deepening of voice 
• Clitoral enlargement (may be irreversible) 
• Swelling of face, hands  or feet 
• Acne (see skin reactions) 
• Loss  of fertility.  Meaning, your ability to conceive  or father a child may be affected by fluoxymesterone.  Discuss this issue with  your health care provider. 
• These side effects are less common side effects (occurring in about 10-29%) of patients receiving fluoxymesterone: 
• Facial hair growth (on women) 
• Increased appetite/weight gain 
• Nausea  
• Temporary decrease in thyroid hormone T4 (thyroxine).  Thyroid function does not appear  to be affected.  (see blood test abnormalities. 
• Increased or decreased libido (see sexuality). 

A rare, but potentially serious side effect of  fluoxymesterone is the development of hepatic adenomas (liver tumors), hepatocellular cancer (liver cancer) or other liver problems.  This can occur after long-term use.
 
Your fertility, meaning your ability to conceive or father a child, may be affected by fluoxymesterone.  Please discuss this issue with your health care provider. 

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: 

• Nausea (interferes with ability to eat and unrelieved with prescribed medication) 
• Swelling, redness and/or pain  in one leg or arm and not  the other 
• Yellowing  of the skin or eyes 
• Swelling  of the feet  or ankles.  Sudden weight gain 

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

Precautions:

• Before starting fluoxymesterone treatment, make sure you tell  your doctor about any other medications you are taking (including prescription, over-the-counter, vitamins, herbal remedies, etc.).   
• Fluoxymesterone can affect serum glucose levels in diabetic patients.  Patients with diabetes should monitor their glucose carefully.  Medication to treat  the diabetes may need  to be altered. 
• Inform  your health care professional if you are pregnant or may be pregnant prior  to starting this treatment. Pregnancy category X (fluoxymesterone may cause fetal harm when given to a pregnant woman.  This drug must not be given to a pregnant woman or a woman who intends to become pregnant.  If a woman becomes pregnant while taking fluoxymesterone, the medication must be stopped immediately and the woman given appropriate counseling). 
• For both men and women:  Do not conceive a child (get pregnant) while taking fluoxymesterone. 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 this  medication.

Self-care tips: 

• Drink at least two to three quarts of fluid every 24 hours, unless you are instructed otherwise.   
• 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  you health care provider if these worsen, or become intolerable. 
• This medication 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 checked regularly by your health care professional while you are taking fluoxymesterone, to monitor side effects and check your response to therapy.  Periodic blood work to monitor the function of organs (such as your kidneys and liver) will be ordered by your doctor.     

How this drug 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 therapy can 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. 

Fluoxymesterone is classified as an androgen.  Androgens are hormones such as testosterone and androsterone that produce or stimulate the development of male characteristics.  In women, these hormones can be converted into estrogen.  Androgens as cancer therapy are used to oppose the activity of estrogen, thereby slowing the growth of cancer.