Pronunciation:

ta-MOX-i-fen

Brand Names:

• Nolvadex
• Soltamox

Dosage Forms:

• Solution
• Tablet

Warnings:

For Women with Ductal Carcinoma in Situ (DCIS) and Women at High Risk for Breast Cancer: Serious and life-threatening events associated with tamoxifen citrate in the risk reduction setting (women at high risk for cancer and women with DCIS) include uterine malignancies, stroke and pulmonary embolism. Incidence rates for these events were estimated from the National Surgical Adjuvant Breast and Bowel Project's P-1 (NSABP P-1) trial. Uterine malignancies consist of both endometrial adenocarcinoma (incidence rate per 1,000 women-years of 2.20 for tamoxifen citrate versus 0.71 for placebo) and uterine sarcoma (incidence rate per 1,000 women-years of 0.17 for tamoxifen citrate versus 0.4 for placebo). For stroke, the incidence rate per 1,000 women-years was 1.43 for tamoxifen citrate versus 1 for placebo. For pulmonary embolism, the incidence rate per 1,000 women-years was 0.75 for tamoxifen citrate versus 0.25 for placebo.

Some of the strokes, pulmonary emboli, and uterine malignancies were fatal.

Health care providers should discuss the potential benefits versus the potential risks of these serious events with women at high risk of breast cancer and women with DCIS considering tamoxifen citrate to reduce their risk of developing breast cancer.

The benefits of tamoxifen citrate outweigh its risks in women already diagnosed with breast cancer .

Serious and life-threatening uterine malignancies, stroke, and pulmonary embolism have been associated with tamoxifen use in the risk reduction setting (women with Ductal Carcinoma in Situ (DCIS) and women at high risk for breast cancer). Some of these adverse events were fatal. Health care providers should discuss the potential benefits versus the potential risks of these serious events with women at high risk of breast cancer and women with DCIS considering tamoxifen to reduce their risk of developing breast cancer. The benefits of tamoxifen outweigh its risks in women already diagnosed with breast cancer .

Classifications:

Therapeutic—

Antiestrogen

Uses of This Medicine:

Tamoxifen is a medicine that blocks the effects of the estrogen hormone in the body. It is used to treat breast cancer in women or men. It may also be used to treat other kinds of cancer, as determined by your doctor.

Tamoxifen also may be used to reduce the risk of developing breast cancer in women who have a high risk of developing breast cancer. Women at high risk for developing breast cancer are at least 35 years of age and have a combination of risk factors that make their chance of developing breast cancer 1.67% or more over the next 5 years. Your doctor will help to determine your risk of developing breast cancer.

• If you have close family members (mother, sister, or daughter) with breast cancer
• If you have ever had a breast biopsy or if high-risk changes in your breast(s) have been found from a breast biopsy
• If you have never been pregnant or if your first pregnancy occurred at a late age
• If your first menstrual period occurred at an early age

The exact way that tamoxifen works against cancer is not known, but it may be related to the way it blocks the effects of estrogen on the body.

Before you begin treatment with tamoxifen, you and your doctor should talk about the good this medicine will do as well as the risks of using it.

Tamoxifen is available only with your doctor's prescription.

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, tamoxifen is used in certain patients with the following medical conditions:

• Malignant melanoma (a certain type of skin cancer)
• Cancer of the endometrium (lining of the uterus)

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies—

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Older adults—

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of tamoxifen in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Pregnancy—

	Pregnancy Category	Explanation
All Trimesters	D	Studies in pregnant women have demonstrated a risk to the fetus. However, the benefits of therapy in a life threatening situation or a serious disease, may outweigh the potential risk.

Breast-feeding—

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Other medicines—

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Acenocoumarol
• Cyclophosphamide
• Dicumarol
• Fluorouracil
• Genistein
• Ipriflavone
• Methotrexate
• Mitomycin
• Phenprocoumon
• Red Clover
• St John's Wort
• Warfarin

Other interactions—

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems—

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Blood problems or
• Cataracts or other eye problems—Tamoxifen may also cause these problems

• High cholesterol levels in the blood—Tamoxifen can increase cholesterol levels

• Blood clots (or history of) or
• Pulmonary embolism (or history of) or
• Stroke or
• Uterine (womb) cancer—May increase risk of serious side effects from tamoxifen.

Proper Use of This Medicine:

Use this medicine only as directed by your doctor. Do not use more or less of it, and do not use it more often than your doctor ordered. The exact amount of medicine you need has been carefully worked out. Taking too much may increase the chance of side effects, while taking too little may not improve your condition.

Tamoxifen sometimes causes mild nausea and vomiting. However, it may have to be taken for several weeks or months to be effective. Even if you begin to feel ill, do not stop using this medicine without first checking with your doctor. Ask your health care professional for ways to lessen these effects.

Swallow the tablets whole with a drink of water. You can take the tablets with or without food.

If you vomit shortly after taking a dose of tamoxifen, check with your doctor. You will be told whether to take the dose again or to wait until the next scheduled dose.

Dosing—

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For oral dosage form (tablets)
  • For breast cancer in women or men:
    • Adults—20 to 40 milligrams (mg) daily.
  • For reducing the risk of developing breast cancer in high-risk women:
    • Adults—20 milligrams (mg) a day, for five years
  • For reducing the risk of developing invasive breast cancer in women with ductal carcinoma in situ:
    • Adults—20 milligrams (mg) a day, for five years

Missed dose—

If you miss a dose of this medicine, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Call your doctor or pharmacist for instructions.

Storage—

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Precautions While Using This Medicine:

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

A woman should contact her healthcare profession right away if she develops:

• Changes in vaginal discharge or
• Changes in vision or
• Coughing up blood or
• Leg swelling or tenderness or
• Menstrual irregularities or
• New breast lumps or
• Pelvic pain or pressure or
• Sudden chest pain or
• Unexplained shortness of breath or
• Vaginal bleeding

If you seek medical attention for any reason, be sure to tell your healthcare professional that you take tamoxifen or have taken tamoxifen.

For women: Tamoxifen may make you more fertile. It is best to use some type of birth control while you are taking it. However, do not use oral contraceptives (“the Pill”) since they may change the effects of tamoxifen. Tell your doctor right away if you think you have become pregnant while taking this medicine.

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Some side effects will have signs or symptoms that you can see or feel. Your doctor will watch for others by doing certain tests.

Also, because of the way this medicine acts on the body, there is a chance that it might cause other 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.

Check with your doctor as soon as possible if any of the following side effects occur:

For both females and males

Less common or rare

Anxiety

blistering, peeling, or loosening of skin and mucous membranes

blurred vision

chest pain

confusion

cough

dizziness

fainting

fast heartbeat

lightheadedness

pain or swelling in legs

shortness of breath or trouble breathing

weakness or sleepiness

yellow eyes or skin

For females only

Less common or rare

Change in vaginal discharge

chills

fever

hoarseness

lower back or side pain

pain or feeling of pressure in pelvis

pain, redness, or swelling in your arm or leg

painful or difficult urination

rapid shallow breathing

skin rash or itching over the entire body

sweating

vaginal bleeding

wheezing

For females and males

Frequency not determined

Bloating

constipation

darkened urine

diarrhea

difficult breathing

indigestion

itching

joint or muscle pain

large, hard skin blisters

large hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, and sex organs

loss of appetite

nausea

pain in stomach or side, possibly radiating to the back

red, irritated eyes

red skin lesions, often with a purple center

sore throat

sores, ulcers or white spots in mouth or on lips

unusual tiredness or weakness

vomiting

This medicine may also cause the following side effect that your doctor will watch for:

For both females and males

Less common or rare

Cataracts in the eyes or other eye problems

liver problems

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:

For both females and males

Less common

Bone pain

headache

nausea and/or vomiting (mild)

skin rash or dryness

For females only

More common

Absent, missed, or irregular periods

confusion

decrease in amount of urine

feeling of warmth redness of the face, neck, arms and occasionally, upper chest

lower back or side pain

menstrual changes

nausea

noisy, rattling breathing

painful or difficult urination

rapid, shallow breathing

skin changes

stopping of menstrual bleeding

swelling of fingers, hands, feet, or lower legs

troubled breathing at rest

vaginal bleeding

weight gain

weight loss

white or brownish vaginal discharge

Less common or rare

Abdominal cramps

black, tarry stools

bleeding gums

blood in urine or stools

Bluish color changes in skin color

discouragement

feeling sad or empty

irritability

itching in genital area

lack of appetite

loss of interest or pleasure

pain

pinpoint red spots on skin

stomach or pelvic discomfort, aching or heaviness

swelling

trouble concentrating

trouble sleeping

unusual bleeding or bruising

For males only

Less common

decreased interest in sexual intercourse

inability to have or keep an erection

loss in sexual ability, desire, drive, or performance

This medicine may infrequently cause hair thinning or partial loss of hair.

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