Description and Brand Names

Drug information provided by: IBM Micromedex

US Brand Name

  1. Nolvadex
  2. Soltamox

Descriptions


Tamoxifen is used to treat certain types of breast cancer (eg, estrogen receptor-positive breast cancer that has spread to other parts of the body [metastatic], early stage estrogen receptor-positive breast cancer after surgery and radiation treatment). It is also used to reduce the risk of invasive breast cancer in adult women with ductal carcinoma in situ (DCIS) after breast surgery and radiation treatment.

Tamoxifen is also used to reduce the risk for breast cancer in women with a high chance of getting it. The following are risk factors that may increase 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.

Female hormones called estrogen, that occur naturally in the body can increase the growth of some breast cancers. Tamoxifen works by blocking the effects of estrogen in the body.

This medicine is available only with your doctor's prescription.

This product is available in the following dosage forms:

  • Solution
  • Tablet

Before Using

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.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of tamoxifen in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of tamoxifen in the elderly.

Breastfeeding

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.

Drug Interactions

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 this medicine, 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 this medicine 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.

  • Acenocoumarol
  • Bepridil
  • Cisapride
  • Dronedarone
  • Fluconazole
  • Ketoconazole
  • Mesoridazine
  • Nelfinavir
  • Phenprocoumon
  • Pimozide
  • Piperaquine
  • Posaconazole
  • Saquinavir
  • Sparfloxacin
  • Terfenadine
  • Thioridazine
  • Warfarin
  • Ziprasidone

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.

  • Abametapir
  • Abiraterone Acetate
  • Amiodarone
  • Amisulpride
  • Anagrelide
  • Apomorphine
  • Aripiprazole
  • Aripiprazole Lauroxil
  • Arsenic Trioxide
  • Buprenorphine
  • Buserelin
  • Capecitabine
  • Carbamazepine
  • Ceritinib
  • Chloroquine
  • Cinacalcet
  • Clarithromycin
  • Clobazam
  • Clofazimine
  • Clozapine
  • Conivaptan
  • Crizotinib
  • Cyclophosphamide
  • Dabrafenib
  • Darunavir
  • Dasatinib
  • Degarelix
  • Delamanid
  • Deslorelin
  • Deutetrabenazine
  • Domperidone
  • Donepezil
  • Doxepin
  • Doxifluridine
  • Efavirenz
  • Encorafenib
  • Entrectinib
  • Enzalutamide
  • Escitalopram
  • Fingolimod
  • Fluoroestradiol F 18
  • Fluorouracil
  • Fluoxetine
  • Fluvoxamine
  • Formoterol
  • Foscarnet
  • Fosnetupitant
  • Fosphenytoin
  • Fostemsavir
  • Genistein
  • Glasdegib
  • Gonadorelin
  • Goserelin
  • Histrelin
  • Hydroxychloroquine
  • Hydroxyzine
  • Inotuzumab Ozogamicin
  • Ipriflavone
  • Ivabradine
  • Ivosidenib
  • Lefamulin
  • Lenvatinib
  • Levofloxacin
  • Lofexidine
  • Lumacaftor
  • Macimorelin
  • Methadone
  • Methotrexate
  • Metronidazole
  • Mitomycin
  • Mitotane
  • Moclobemide
  • Moxifloxacin
  • Nafarelin
  • Netupitant
  • Nilotinib
  • Ondansetron
  • Osilodrostat
  • Osimertinib
  • Oxaliplatin
  • Ozanimod
  • Panobinostat
  • Paroxetine
  • Pasireotide
  • Pazopanib
  • Phenytoin
  • Pimavanserin
  • Pitolisant
  • Quetiapine
  • Quinine
  • Red Clover
  • Ribociclib
  • Rifampin
  • Rolapitant
  • Selpercatinib
  • Sertraline
  • Sevoflurane
  • Siponimod
  • Solifenacin
  • Sotalol
  • St John's Wort
  • Sulpiride
  • Sunitinib
  • Tacrolimus
  • Tegafur
  • Trazodone
  • Triclabendazole
  • Triptorelin
  • Vandetanib
  • Vemurafenib
  • Vinflunine
  • Zuclopenthixol

Using this medicine 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

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 clots (eg, deep vein thrombosis, pulmonary embolism) or history of—Should not be used in patients with this condition.
  • Eye or vision problems (eg, cataracts) or
  • Hypercalcemia (high calcium levels in the blood) or
  • Hyperlipidemia (high cholesterol levels in the blood) or
  • Liver disease or
  • Stroke, history of—Use with caution. May make these conditions worse.

Proper Use

Use this medicine only as directed by your doctor. Do not use more of it, do not use it more often, and do not take it for a longer time than your doctor ordered.

Medicines used to treat cancer are very strong and can have many side effects. Before using this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.

This medicine comes with a Medication Guide. Read and follow these instructions carefully. Ask your doctor if you have any questions.

Shake the oral liquid well before each use. Measure the medicine with a marked medicine cup. The average household teaspoon may not hold the right amount of liquid.

Swallow the tablets whole with a glass of water. Do not break, divide, crush, or chew it. You can take the tablets with or without food.

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.

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 (solution, tablets):
    • For breast cancer:
      • Adults—20 to 40 milligrams (mg) per day. Doses greater than 20 mg are given as 2 divided doses per day (morning and evening).
      • Children—Use and dose must be determined by your doctor.
    • For breast cancer as additional treatment:
      • Adults—20 milligrams (mg) per day for 5 to 10 years.
      • 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) per day for 5 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) per day for 5 years.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

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.

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

Do not store the oral liquid in the refrigerator or freezer. Throw away any unused liquid after 3 months of first opening the bottle.

Precautions

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Do not use this medicine together with blood thinners (eg, warfarin).

Your doctor will give you a pregnancy test before you use this medicine to make sure you are not pregnant. Using this medicine while you are pregnant can harm your unborn baby. Birth control pills may not work as well to prevent pregnancy when used with this medicine. Use another form of birth control (eg, condoms, spermicide) along with your pills during treatment and for 2 months after the last dose. If you think you have become pregnant while using the medicine, tell your doctor right away.

This medicine may increase your risk for other cancers, including endometrium, liver, or uterus cancer. Tell your doctor if you have any changes in your menstrual period, such as irregular menstrual periods or no menstrual periods, or abnormal vaginal bleeding. It is important for women to have regular gynecologic check-ups while using this medicine. Talk to your doctor if you have concerns.

This medicine may increase your risk of developing blood clots. Check with your doctor right away if you have swelling and pain in your arms, legs, or stomach, chest pain, shortness of breath, loss of sensation, confusion, or problems with muscle control or speech.

This medicine may lower the number of some types of blood cells in your body. Because of this, you may bleed or get infections more easily. To help with these problems, avoid being near people who are sick or have infections. Wash your hands often. Stay away from rough sports or other situations where you could be bruised, cut, or injured. Brush and floss your teeth gently. Be careful when using sharp objects, including razors and fingernail clippers.

Check with your doctor right away if blurred vision, difficulty with reading, or any other change in vision occurs during or after treatment. Your doctor may want your eyes be checked by an ophthalmologist (eye doctor).

Make sure any doctor or dentist who treats you knows that you are using this medicine. This medicine may affect the results of certain medical tests.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects

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:

More common

  1. Absent, missed, or irregular menstrual periods
  2. bladder pain
  3. blindness
  4. bloating or swelling of the face, arms, hands, lower legs, or feet
  5. bloody or cloudy urine
  6. blurred vision
  7. chills
  8. confusion
  9. cough
  10. decrease in the amount of urine
  11. decrease in height
  12. decreased vision
  13. difficult or labored breathing
  14. difficult, burning, or painful urination
  15. dizziness
  16. fainting
  17. fast heartbeat
  18. fever
  19. frequent urge to urinate
  20. heavy non-menstrual vaginal bleeding
  21. hoarseness
  22. increased clear or white vaginal discharge
  23. lower back or side pain
  24. noisy, rattling breathing
  25. pain in the back, ribs, arms, or legs
  26. painful or difficult urination
  27. pale skin
  28. rapid weight gain
  29. rapid, shallow breathing
  30. stopping of menstrual bleeding
  31. tightness in the chest
  32. tingling of the hands or feet
  33. troubled breathing at rest
  34. troubled breathing with exertion
  35. unusual bleeding or bruising
  36. unusual tiredness or weakness
  37. unusual weight gain or loss

Less common

  1. Abnormal growth filled with fluid or semisolid material
  2. black, tarry stools
  3. bleeding gums
  4. bloating
  5. blurred vision
  6. breast pain, redness, or swelling
  7. chest pain
  8. clear or bloody discharge from the nipple
  9. cough producing mucus
  10. dimpling of the breast skin
  11. feeling of warmth or heat
  12. flushing or redness of the skin, especially on the face and neck headache
  13. inverted nipple
  14. joint pain or stiffness
  15. large amount of cholesterol in the blood
  16. lump in the breast or under the arm
  17. nervousness
  18. persistent crusting or scaling of the nipple
  19. pinpoint red spots on the skin
  20. pounding in the ears
  21. skin rash or itching over the entire body
  22. slow heartbeat
  23. sore on the skin of the breast that does not heal
  24. stomach or pelvic discomfort, aching, or heaviness

Rare

  1. Anxiety
  2. bluish color of the skin
  3. tenderness

Incidence not known

  1. Blistering, peeling, loosening of the skin
  2. constipation
  3. dark urine
  4. diarrhea
  5. general feeling of discomfort or illness
  6. indigestion
  7. muscle pain
  8. large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or genitals
  9. loss of appetite
  10. nausea
  11. pains in the stomach, side, or abdomen, possibly radiating to the back
  12. red skin lesions, often with a purple center
  13. red, irritated eyes
  14. sore throat
  15. sores, ulcers, or white spots in the mouth or on the lips
  16. thickening of bronchial secretions
  17. vomiting
  18. yellow eyes or skin

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

  1. Back pain
  2. belching
  3. body aches or pain
  4. bone pain
  5. congestion
  6. depression
  7. difficulty in moving
  8. dryness of the throat
  9. hair loss or thinning of hair
  10. heartburn
  11. joint swelling
  12. lack or loss of strength
  13. mood changes
  14. muscle cramps or stiffness
  15. passing of gas
  16. redness of the face, neck, arms, and occasionally, upper chest
  17. runny nose
  18. shivering
  19. skin changes
  20. stomach upset, fullness, or pain
  21. sudden sweating
  22. tender, swollen glands in the neck
  23. trouble in swallowing
  24. trouble sleeping
  25. voice changes

Less common

  1. Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  2. itching of the vagina or genital area
  3. pain during sexual intercourse

Incidence not known

  1. Decreased interest in sexual intercourse
  2. inability to have or keep an erection
  3. loss in sexual ability, desire, drive, or performance

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.