Tamoxifen citrate

What is Tamoxifen citrate?

Tamoxifen, an anticancer drug, is given to treat breast cancer in women and men. It also has been proven to be effective when cancer has spread to other parts of the body.

Tamoxifen is also used to help lower the chance of getting breast cancer in women with a higher than normal risk of getting breast cancer in the next five years (high-risk women).

In addition, tamoxifen is used to reduce the risk of breast cancer spreading in women who have ductal carcinoma in situ (DCIS) (breast cancer located in the milk ducts which has not spread) and have already undergone breast cancer surgery and radiation therapy

What is the most important information I should know about Tamoxifen citrate?

Although tamoxifen reduces the risk of breast cancer, it may increase the possibility of developing endometrial (uterine) cancer in women. It is important for women to have annual gynecological exams while on tamoxifen and after discontinuing therapy with tamoxifen. Women should notify their physician immediately, if they develop abnormal vaginal bleeding, changes in vaginal discharge, or an increase in pelvic pain or pressure.

Tamoxifen may also cause other types of cancer in addition to uterine cancer.

Tamoxifen may cause women to develop non-malignant changes in their uterus. This includes endometriosis, fibroids in the uterus, menstrual cycle irregularities or the absence of menstrual periods.

Tamoxifen may increase the chances of developing a blood such as a clot in the lung or a blood clot in the leg.

Tamoxifen may increase the chance of developing liver cancer and liver abnormalities such as hepatitis.

Tamoxifen may cause eye problems. This includes vision changes, damage to the retina of the eye, clots within the blood vessels of the eye, and cataracts.

Tamoxifen may cause fetal harm if used during pregnancy. Women should not take tamoxifen if they are pregnant or planning to become pregnant. They should also not become pregnant for two months following discontinuation of tamoxifen. Women who have not gone through menopause and are sexually active, should use an effective nonhormonal contraceptive (e.g., condoms, diaphragm) while on tamoxifen and for two months after discontinuing tamoxifen.

Tamoxifen may affect components of your blood. This includes: very low platelet counts (thrombocytopenia), very low white blood cell counts (leukopenia), and low neutrophil counts (neutropenia).

Who should not take Tamoxifen citrate?

Do not take tamoxifen if you are allergic to it or any of its components. Do not take tamoxifen if you are pregnant, planning to become pregnant, or are nursing. Also, women who are on coumarin-type anticoagulant therapy (such as warfarin), have a history of deep-vein thrombosis (such as a blood clot in the leg), or have a history of a blood clot developing in their lung, should not take tamoxifen.

What should I tell my doctor before I take the first dose of Tamoxifen citrate?

Tell your doctor about all prescription, over-the-counter, and herbal medications you are taking before beginning treatment with tamoxifen. Also, talk to your doctor about your complete medical history, especially if you are a women who is on coumarin-type anticoagulant therapy (such as warfarin), has a history of deep vein thrombosis (such as a blood clot in your leg), or a pulmonary embolus (blood clot in your lung). In addition, notify your physician if you are pregnant, planning to become pregnant, or are nursing.

What is the usual dosage?

The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.

Breast Cancer Prevention

The usual starting dose is 20 mg once a day for up to 5 years.

Breast Cancer Treatment

The usual dosage ranges from 20 to 40 milligrams (mg) daily. If you are taking more than 20 milligrams (mg) a day, your doctor will have you divide the total into two smaller doses taken in the morning and evening.

Ductal Carcinoma in Situ

The usual dose is 20 milligrams (mg) daily for 5 years.

To Reduce the Incidence of Breast Cancer in High Risk Women

The usual dose is 20 milligrams (mg) daily for 5 years.

How should I take Tamoxifen citrate?

Swallow the tamoxifen tablet(s) whole, with water or another non-alcoholic liquid. You can take tamoxifen with or without food. Take your medicine every day. It may be easier to remember if you take it at the same time each day. Take tamoxifen tablets for 5 years, unless your doctor tells you otherwise.

What should I avoid while taking Tamoxifen citrate?

Do not become pregnant while taking tamoxifen or for 2 months after you stop taking tamoxifen. Tamoxifen can prevent hormonal birth control methods (e.g., birth control pills, patches, injections, rings and implants) from working. Therefore, while taking tamoxifen, use birth control methods that don't use hormones, such as condoms, diaphragms with spermicide, or plain intrauterine devices (IUDs). If you get pregnant, stop taking tamoxifen right away and call your doctor. Do not breast feed if you are using tamoxifen.

What are possible food and drug interactions associated with Tamoxifen citrate?

If tamoxifen is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining tamoxifen with the following: aminoglutethimide, anastrazole, bromocriptine, coumarin-type anticoagulants (such as warfarin), cytotoxic agents, letrozole, medroxyprogesterone, rifampin, and phenobarbital.

What are the possible side effects of Tamoxifen citrate?

Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking this drug.

Side effects may include: cataracts, changes in menstrual period, constipation, diarrhea, fluid retention, flushing, hot flashes, edema (swelling), fatigue, headache, high blood pressure levels, muscle pain, nausea, shortness of breath, vaginal discharge, vomiting, weight loss

Can I receive Tamoxifen citrate if I am pregnant or breastfeeding?

Avoid taking tamoxifen if you are pregnant, planning to become pregnant, or are breastfeeding.

What should I do if I miss a dose of Tamoxifen citrate?

If you miss a dose of tamoxifen, take it when you remember, then take the next dose as usual. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take a double dose.

How should I store Tamoxifen citrate?

Store at room temperature in a tightly closed, light-resistant container.