When preventing breast cancer with tamoxifen, dosing guidelines call for a starting dose of 20 mg a day. The dosage can range from 20 to 40 mg a day when used to treat the condition. Tamoxifen dosing guidelines are also affected by the stage and severity of breast cancer, if other medications are being taken, and if other medical conditions are present.
Tamoxifen Dosing: An IntroductionThe dose of tamoxifen citrate (Nolvadex®) that your healthcare provider recommends will vary, depending on a number of factors, including:
- The severity of your breast cancer (see Breast Cancer Stages)
- Whether you are using tamoxifen to treat or prevent breast cancer
- Other medications you may be taking
- Other medical conditions you may have.
As is always the case, do not adjust your tamoxifen dosage unless your healthcare provider specifically instructs you to do so.
Tamoxifen Dosing for Breast Cancer TreatmentThe recommended dose of tamoxifen for treating breast cancer is tamoxifen 20 to 40 mg daily. Doses larger than 20 mg per day should be split up into two smaller doses.
Tamoxifen Dosing for Breast Cancer Prevention or Ductal CarcinomaThe recommended dose of tamoxifen for preventing breast cancer or for treating ductal carcinoma in situ (DCIS) is tamoxifen 20 mg, taken once daily for five years.
General Information on Tamoxifen DosingConsiderations for people taking tamoxifen include the following:
- The medication comes in tablet form and is taken by mouth once or twice a day.
- Tamoxifen can be taken with or without food. If it bothers your stomach, try taking it with food.
- The medication should be taken at the same time(s) each day to maintain an even level in your blood.
- For the medication to work properly, it must be taken as prescribed. Tamoxifen will not work if you stop taking it.
- If you are unsure about anything related to tamoxifen or tamoxifen dosing, talk to your doctor, nurse, or pharmacist. Do not stop taking the drug without discussing it with your healthcare provider.