This information from Lexicomp® explains what you need to know about this medication, including what it’s used for, how to take it, its side effects, and when to call your healthcare provider.
APO-Tamox; Nolvadex D; TEVA-Tamoxifen
- This drug may raise the chance of very bad and sometimes deadly side effects like stroke, blood clots, or endometrial or uterine cancer.
- It is used to treat breast cancer.
- It is used to lower the chance of breast cancer in people with a higher chance of getting it. It may lower the chance of getting cancer in the other breast after one has cancer.
- It may be given to you for other reasons. Talk with the doctor.
- If you have an allergy to tamoxifen or any other part of this drug.
- If you are allergic to this drug; any part of this drug; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
- If you have blood clots or have had blood clots in the past.
- If you are taking any of these drugs: Anastrozole, letrozole, or warfarin.
- If you are taking any of these drugs: Carbamazepine, phenobarbital, phenytoin, rifabutin, rifampin, or St. John’s wort.
- If you are breast-feeding. Do not breast-feed while you take this drug or for 3 months after your last dose.
This is not a list of all drugs or health problems that interact with this drug.
Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this drug with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
- Tell all of your health care providers that you take this drug. This includes your doctors, nurses, pharmacists, and dentists.
- Have blood work checked as you have been told by the doctor. Talk with the doctor.
- This drug may affect certain lab tests. Tell all of your health care providers and lab workers that you take this drug.
- Low blood cell counts have happened with this drug. If blood cell counts get very low, this can lead to bleeding problems, infections, or anemia. Call your doctor right away if you have signs of infection like fever, chills, or sore throat; any unexplained bruising or bleeding; or if you feel very tired or weak.
- Call your doctor right away if you have signs of a blood clot like chest pain or pressure; coughing up blood; shortness of breath; swelling, warmth, numbness, change of color, or pain in a leg or arm; or trouble speaking or swallowing.
- This drug may raise the chance of getting cataracts or the need to have cataract surgery. Talk with the doctor.
- Be sure to have regular breast exams. Your doctor will tell you how often to have these. You will also need to do breast self-exams as your doctor has told you. Talk with your doctor.
- Be sure to have regular gynecology check-ups. Your doctor will tell you how often to have these.
- Other cancers have been reported with this drug. It is not known if this drug was the reason for the other cancers. If you have questions, talk with your doctor.
- This drug may stop you from having a period (menstrual bleeding) for some time. This is not a method of birth control.
- This drug may cause harm to an unborn baby. A pregnancy test will be done before you start this drug to show that you are NOT pregnant.
- Use birth control that does not have hormones in it like a condom. Do this for as long as you take this drug and for 2 months after you stop taking it.
- If you get pregnant while taking this drug or within 2 months after your last dose, call your doctor right away.
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Signs of high calcium levels like weakness, confusion, feeling tired, headache, upset stomach and throwing up, constipation, or bone pain.
- Signs of a urinary tract infection (UTI) like blood in the urine, burning or pain when passing urine, feeling the need to pass urine often or right away, fever, lower stomach pain, or pelvic pain.
- Weakness on 1 side of the body, trouble speaking or thinking, change in balance, drooping on one side of the face, or blurred eyesight.
- Change in eyesight.
- A lump in the breast or breast soreness.
- Low mood (depression).
- Swelling in the arms or legs.
- Any skin change.
- Very bad headache.
- A burning, numbness, or tingling feeling that is not normal.
- Rarely, liver problems have happened with this drug. This includes some cases of liver cancer. Sometimes, liver problems have been deadly. Call your doctor right away if you have signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
- If you are female, call your doctor right away if you have pain when passing urine, pelvic pain or pressure, period (menstrual) changes like no period, vaginal bleeding that is not normal, or vaginal discharge.
- Some males have had sexual problems when taking this drug. These include lowered interest in sex and not able to get an erection. Call your doctor right away if you have sexual problems when taking this drug.
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Hot flashes.
- Upset stomach or throwing up.
- Weight gain or loss.
- Feeling dizzy, tired, or weak.
- Back, bone, joint, or muscle pain.
- Diarrhea or constipation.
- Trouble sleeping.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to your national health agency.
Use this drug as ordered by your doctor. Read all information given to you. Follow all instructions closely.
- Take with or without food.
- Keep taking this drug as you have been told by your doctor or other health care provider, even if you feel well.
- If you are able to get pregnant, start taking this drug during your period (menstrual) cycle. If you are not sure when to start taking this drug, talk with your doctor.
- Swallow whole with some water or other drink.
- Only use the measuring device that comes with this liquid drug.
- Take a missed dose as soon as you think about it.
- If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
- Do not take 2 doses at the same time or extra doses.
- If you are not sure what to do if you miss a dose, call your doctor.
- Store at room temperature in a dry place. Do not store in a bathroom.
- Store at room temperature. Do not refrigerate or freeze.
- Store in a dry place. Do not store in a bathroom.
- Store in original container.
- Keep lid tightly closed.
- Throw away any part not used 90 days after opening.
- Protect from heat and light.
- Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
- Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
- If your symptoms or health problems do not get better or if they become worse, call your doctor.
- Do not share your drugs with others and do not take anyone else’s drugs.
- Some drugs may have another patient information leaflet. If you have any questions about this drug, please talk with your doctor, nurse, pharmacist, or other health care provider.
- This drug comes with an extra patient fact sheet called a Medication Guide. Read it with care. Read it again each time this drug is refilled. If you have any questions about this drug, please talk with the doctor, pharmacist, or other health care provider.
- If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
© 2022 UpToDate, Inc. and its affiliates and/or licensors. All rights reserved.