Source: Medicines & Healthcare Products Regulatory Agency (GB) Revision Year: 2018 Publisher: Generics [UK] Ltd t/a Mylan, Station Close, Potters Bar, Herts, EN6 1TL
As an orally active anti-oestrogen in the treatment of breast cancer. Also used to stimulate ovulation in anovulatory infertility.
It is also indicated for the primary prevention of breast cancer in women at moderate or high risk (see section 5.1).
Women aged less than 30 years old were excluded from primary prevention trials so the efficacy and safety of tamoxifen treatment in these younger women is unknown.
The recommended daily dose of Tamoxifen is normally 20 mg. No additional benefit, in terms of delayed recurrence or improved survival in patients, has been demonstrated with higher doses. Substantive evidence supporting the use of treatment with 30-40 mg per day is not available, although these doses have been used in some patients with advanced disease.
The possibility of pregnancy must be excluded before the commencement of treatment, whether initial or subsequent. In women with regular menstruation but with anovular cycles, treatment should commence with 20 mg daily in either one or two doses administered on the second, third, fourth and fifth days of the menstrual cycle. In unsuccessful cases further courses may be given during subsequent menstrual periods, increasing the dosage to 20 mg then 40 mg twice daily.
In women with irregular menstruation, the commencement of treatment may take place on any day. If this initial course is not successful then a further course may be initiated after an interval of 45 days with the higher dosage level (20 mg to 40 mg twice daily).
If a patient responds with menstruation then the next course of treatment should be initiated on the second day of the cycle.
Tamoxifen treatment for the primary prevention of breast cancer should only be initiated by a medical practitioner experienced in prescribing for this indication, and as part of a shared care pathway arrangement, with appropriate patient identification, management and follow up.
The recommended dose is 20 mg daily for 5 years for those women at moderate or high risk. There are insufficient data to support a higher dose or longer period of use.
Before commencing treatment, an assessment of the potential benefits and risks is essential, including calculating a patient’s risk of developing breast cancer according to local guidelines and risk assessment tools. Validated algorithms are available that calculate breast cancer risk based on features such as age, family history, genetic factors, reproductive factors and history of breast disease.
The use of Tamoxifen should be as part of a program including regular breast surveillance tailored to the individual woman, taking into account her risk of breast cancer.
The adult dosage range has been used in elderly patients with breast cancer and in some of these patients it has been used as sole therapy.
The use of tamoxifen is not recommended in children and adolescents, as safety and efficacy have not been established (see sections 5.1 and 5.2).
For oral administration (use) only.
An overdosage would be expected to cause enhancement of the anti-oestrogenic side effects.
Animal studies have demonstrated that extremely high dosage (greater than 100 times the recommended daily dose) may cause oestrogenic effects.
There have been reports in the literature that tamoxifen given at several times the standard dose may be associated with prolongation of the QT interval of an ECG.
There is no specific antidote to overdosage and treatment should be carried out symptomatically.
60 months for polypropylene pots and blisters; 48 months for HDPE.
Do not store above 25°C.
Pots: Keep the pot tightly closed in order to protect from light and moisture.
Blisters: Store in the original package in order to protect from light and moisture.
Polypropylene tablet container with white polyethylene caps and polyethylene ullage filler; and PVC/Aluminium Blister Pack; and High density polyethylene (HDPE) containers with polyethylene snap closures in packs of 5, 7, 10, 14, 20, 21, 25, 28, 30, 50, 56, 60, 100 and 250 tablets.
Not all pack sizes may be marketed.
No special requirements.
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