Lice Buyer's Guide: Treatment Product Reviews Go Now

tamoxifen (Oral route)

Pronunciation

ta-MOX-i-fen

Oral route(Tablet)

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 .

Commonly used brand name(s)

In the U.S.

  • Nolvadex
  • Soltamox

Available Dosage Forms:

  • Solution
  • Tablet

Therapeutic Class: Antiestrogen

Uses For tamoxifen

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.

Slideshow: 2013 Drug News Round-Up - Top 20 Stories

  • The following are risk factors that may increase your chance 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 tamoxifen 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:

  • Breast cancer, neoadjuvant treatment for hormone receptor-positive disease in postmenopausal women.
  • Cancer of the endometrium (lining of the uterus).
  • Malignant melanoma (a certain type of skin cancer).

Before Using tamoxifen

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 tamoxifen, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to tamoxifen 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.

Geriatric

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, tamoxifen 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.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking tamoxifen, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using tamoxifen with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Amifampridine
  • Fluconazole
  • Ketoconazole
  • Nelfinavir
  • Piperaquine
  • Posaconazole
  • Warfarin

Using tamoxifen 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.

  • Abiraterone Acetate
  • Acenocoumarol
  • Aprepitant
  • Carbamazepine
  • Ceritinib
  • Chlorpromazine
  • Clarithromycin
  • Clobazam
  • Cobicistat
  • Crizotinib
  • Cyclophosphamide
  • Dabrafenib
  • Delamanid
  • Desipramine
  • Dicumarol
  • Escitalopram
  • Eslicarbazepine Acetate
  • Fluorouracil
  • Fluoxetine
  • Fluphenazine
  • Fluvoxamine
  • Fosaprepitant
  • Genistein
  • Ipriflavone
  • Ivabradine
  • Methotrexate
  • Mitomycin
  • Mitotane
  • Nitisinone
  • Ondansetron
  • Paroxetine
  • Pazopanib
  • Phenprocoumon
  • Primidone
  • Quetiapine
  • Red Clover
  • Ritonavir
  • Sertraline
  • Sevoflurane
  • Siltuximab
  • St John's Wort
  • Vandetanib
  • Vemurafenib
  • Vinflunine

Using tamoxifen with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Aldesleukin
  • Aminoglutethimide
  • Anastrozole
  • Bexarotene
  • Letrozole
  • Rifampin

Interactions with Food/Tobacco/Alcohol

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 tamoxifen. Make sure you tell your doctor if you have any other medical problems, especially:

  • For all patients
  • 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.
  • When used for reducing the risk for developing breast cancer in high-risk women or in women with Ductal Carcinoma in Situ (DCIS)
  • 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 tamoxifen

Use tamoxifen 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 tamoxifen 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 tamoxifen 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 tamoxifen. 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.
      • Children—Use and dose must be determined by your doctor.
    • For reducing the risk of developing breast cancer in high-risk women:
      • Adults—20 milligrams (mg) a day for five years.
      • Children—Use and dose must be determined by your doctor.
    • 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.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of tamoxifen, 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.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions While Using tamoxifen

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

A woman should contact her doctor 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 doctor 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 tamoxifen.

tamoxifen Side Effects

Because of the way tamoxifen 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
  • Anxiety
  • blistering, peeling, or loosening of the skin and mucous membranes
  • blurred vision
  • cataracts in the eyes or other eye problems
  • change in vaginal discharge
  • chest pain
  • chills
  • confusion
  • cough
  • dizziness
  • fainting
  • fast heartbeat
  • fever
  • hoarseness
  • lightheadedness
  • lower back or side pain
  • pain or feeling of pressure in the pelvis
  • pain or swelling in the legs
  • pain, redness, or swelling in your arm or leg
  • painful or difficult urination
  • rapid shallow breathing
  • shortness of breath or trouble with breathing
  • skin rash or itching over the entire body
  • sweating
  • weakness or sleepiness
  • wheezing
  • vaginal bleeding
  • yellow eyes or skin
Incidence not known
  • Bloating
  • constipation
  • darkened urine
  • diarrhea
  • difficulty with breathing
  • indigestion
  • itching
  • joint or muscle pain
  • large, hard skin blisters
  • large hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, and sex organs
  • loss of appetite
  • nausea
  • pain in the 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 the mouth or on the lips
  • unusual tiredness or weakness
  • 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
  • Absent, missed, or irregular periods
  • decrease in the amount of urine
  • feeling of warmth
  • menstrual changes
  • noisy, rattling breathing
  • redness of the face, neck, arms and occasionally, upper chest
  • skin changes
  • stopping of menstrual bleeding
  • swelling of the fingers, hands, feet, or lower legs
  • troubled breathing at rest
  • weight gain or loss
  • white or brownish vaginal discharge
Less common or rare
  • Abdominal or stomach cramps
  • black, tarry stools
  • bleeding gums
  • blood in the urine or stools
  • bluish color changes in skin color
  • bone pain
  • decreased interest in sexual intercourse
  • discouragement
  • feeling sad or empty
  • hair loss or thinning of the hair
  • headache
  • inability to have or keep an erection
  • irritability
  • itching in the genital area
  • loss of interest or pleasure
  • loss in sexual ability, desire, drive, or performance
  • nausea or vomiting (mild)
  • pain
  • pinpoint red spots on the skin
  • skin rash or dryness
  • stomach or pelvic discomfort, aching, or heaviness
  • swelling
  • trouble concentrating
  • trouble with sleeping
  • 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.

See also: Side effects (in more detail)

The information contained in the Truven Health Micromedex products as delivered by Drugs.com is intended as an educational aid only. It is not intended as medical advice for individual conditions or treatment. It is not a substitute for a medical exam, nor does it replace the need for services provided by medical professionals. Talk to your doctor, nurse or pharmacist before taking any prescription or over the counter drugs (including any herbal medicines or supplements) or following any treatment or regimen. Only your doctor, nurse, or pharmacist can provide you with advice on what is safe and effective for you.

The use of the Truven Health products is at your sole risk. These products are provided "AS IS" and "as available" for use, without warranties of any kind, either express or implied. Truven Health and Drugs.com make no representation or warranty as to the accuracy, reliability, timeliness, usefulness or completeness of any of the information contained in the products. Additionally, TRUVEN HEALTH MAKES NO REPRESENTATION OR WARRANTIES AS TO THE OPINIONS OR OTHER SERVICE OR DATA YOU MAY ACCESS, DOWNLOAD OR USE AS A RESULT OF USE OF THE THOMSON REUTERS HEALTHCARE PRODUCTS. ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE OR USE ARE HEREBY EXCLUDED. Truven Health does not assume any responsibility or risk for your use of the Truven Health products.

Copyright 2014 Truven Health Analytics, Inc. All Rights Reserved.

Hide
(web2)