PatientsLikeMe ™

Back to Treatment Report

What is tamoxifen?

Tamoxifen blocks the actions of estrogen, a female hormone. Certain types of breast cancer require estrogen to grow.

Tamoxifen is used to treat and prevent some types of breast cancer.

Tamoxifen may also be used for other purposes not listed in this medication guide.

Precautions

Instructions

Side-effects

Interactions

Precautions

Do not use this medication if you are allergic to tamoxifen.

Before using tamoxifen, tell your doctor if you are allergic to any drugs, or if you have:

• liver disease;
• high levels of triglycerides (fatty acids) in your blood;
• a history of stroke or blood clot;
• a history of cataract; or
• if you are receiving chemotherapy or radiation treatment.

Taking tamoxifen may increase your risk of uterine cancer, stroke, or a blood clot in the lung, which can be fatal. Talk with your doctor about your specific risks in taking this medication.

FDA pregnancy category D. This medication can cause harm to an unborn baby. Do not use tamoxifen without your doctor’s consent if you are pregnant. Tell your doctor if you become pregnant during treatment. Use a non-hormonal form of birth control (such as a condom or a diaphragm and spermicide) while you are using this medication and for 2 months after your treatment ends.

It is not known whether tamoxifen passes into breast milk or if it could harm a nursing baby. This medication may also slow breast milk production. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Follow your doctor’s instructions about any restrictions on food, beverages, or activity while you are using tamoxifen.

Back to top

Instructions

Seek emergency medical attention if you think you have used too much of this medicine.

An overdose of tamoxifen is not expected to produce life-threatening symptoms.

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

Back to top

Side-effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using tamoxifen and call your doctor at once if you have any of these serious side effects:

• sudden numbness or weakness, especially on one side of the body;
• sudden headache, confusion, problems with vision, speech, or balance;
• chest pain, shortness of breath, or coughing up blood;
• pain or swelling in one or both legs;
• unusual vaginal bleeding or discharge;
• irregular menstrual periods;
• pain or pressure in your pelvic area;
• fever, chills, body aches, flu symptoms;
• pale skin, easy bruising or bleeding;
• new breast lumps; or
• nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects may include:

• hot flashes, warmth or tingly feeling under your skin;
• bone, joint, or tumor pain;
• redness or skin changes;
• swelling in your hands or feet;
• vaginal itching or dryness;
• depressed mood, weakness;
• weight loss;
• nausea;
• cough, sore throat;
• decreased sex drive, impotence, or difficulty having an orgasm;
• headache, dizziness; or
• thinning hair.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

Back to top

Interactions

Many drugs can interact with tamoxifen. Below is just partial list. Tell your doctor if you are using any of these medications:

• aminoglutethimide (Cytadren);
• bromocriptine (Parlodel);
• cimetidine (Tagamet);
• clozapine (Clozaril, FazaClo);
• isoniazid (for treating tuberculosis);
• letrozole (Femara);
• methimazole (Tapazole);
• nicardipine (Cardene);
• pioglitazone (Actos);
• rifampin (Rifadin, Rifater, Rifamate, Rimactane);
• ropinirole (Requip);
• ticlopidine (Ticlid);
• a blood thinner (warfarin, Coumadin);
• anti-malaria medication such as chloroquine (Arelan) or pyrimethamine (Daraprim), or quinine (Qualaquin);
• HIV or AIDS medicine such as delavirdine (Rescriptor) or ritonavir (Norvir);
• an antibiotic such as terbinafine (Lamisil);
• a heart rhythm medication such as amiodarone (Cordarone, Pacerone) or quinidine (Quinidex, Quin-Release Quin-G);
• medicine to treat psychiatric disorders, such as chlorpromazine (Thorazine), haloperidol (Haldol), or thioridazine (Mellaril); or
• an antidepressant such as bupropion (Wellbutrin), clomipramine (Anafranil), desipramine (Norpramin), duloxetine (Cymbalta), fluoxetine (Prozac), imipramine (Tofranil), paroxetine (Paxil), sertraline (Zoloft), or tranylcypromine (Parnate).

This list is not complete and there may be other drugs that can interact with tamoxifen. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Back to top

Disclaimer