Siterone 50mg (Cyproterone)

Siterone general information

What is Siterone used for?

Siterone tablets 50mg are used to treat prostate cancer, a tumour that is dependent on androgens (male hormones like testosterone) to grow. Siterone tablets 50mg are also used to reduce sexual aggression in sex offenders. In women with severe signs of androgenisation (overproduction of androgen), Siterone tablets 50 mg are used to treat hirsutism (unwanted hair) and androgenic alopecia (hair loss) both caused by excess androgen production. Siterone 50mg can also be used, in conjunction with oestrogen supplements as part of the feminisation process for male to female transsexuals.

How does Siterone work?

Siterone tablets 50mg contain cyproterone, which is an anti-androgen that blocks the biological effects of androgens, like the male hormone testosterone, on cells containing androgen receptors. Prostate cancer is an androgen-dependent tumour, which means that it needs testosterone to grow. Cyproterone in Siterone 50mg binds to the androgen receptors on the tumour cells blocking the action of testosterone, which then cannot bind to the cells and stimulate the tumour cells to grow, thereby protecting the prostate from the effect of androgens. Siterone tablets 50mg block biological effects of androgen on other cells with androgen receptors, such as reducing the production of male hormones in the testes, which reduces aggression and increased sex drive (hypersexuality), caused by over-production of testosterone. Women also produce some androgen but in much smaller amounts. However, some women produce too much testosterone, and this can cause hirsutism (unwanted hair), acne and/or seborrhoea (greasy skin from too much sebum) and androgen-dependent alopecia. Siterone tablets 50mg inhibits testosterone production in these women, reducing these unwanted effects. Blocking the effects of androgens is also a means of promoting feminisation in transgender hormone therapy for male to female transsexuals.

What does Siterone contain?

Siterone 50 mg tablets contain the active ingredient cyproterone acetate, which is an antiandrogen and blocks the biological effects of androgens like testosterone. They also contain lactose, maize starch, povidone, colloidal silicon dioxide, magnesium stearate, purified water, pregelatinised starch.

Treating prostate cancer with Siterone

Siterone tablets 50 mg contain the active ingredient cyproterone, which is an anti-androgen that blocks the biological effects of androgens like testosterone. Prostate cancer (prostatic carcinoma) is an androgen-dependent tumour of the prostate gland, which means that it needs testosterone to grow. Cyproterone in Siterone tablets 50mg binds to the androgen receptors on the tumour cells blocking the action of testosterone and its metabolite dihydrotestosterone (DHT), which then cannot bind to the prostate cells and stimulate the tumour cells to grow. Therefore, Siterone tablets 50 mg protect the prostate from the effect of androgens and cause the tumour to stop growing and to shrink. Prostatic carcinoma cells are still inhibited by Siterone, even when they have spread to other parts of the body (metastasised), so that Siterone tablets 50 mg can help prevent the spread of the tumour, although they cannot cure the tumour.

Siterone for feminising hormone therapy

Siterone tablets 50 mg contain the active ingredient cyproterone, which is an antiandrogen that blocks the biological effects of androgens like testosterone. The feminisation process for male to female transsexuals involves achieving female characteristics as well as losing male attributes. Cyproterone works by reducing the production of male hormones in the testes and blocking the action of testosterone, like inducing body hair and beard growth so that Siterone 50 mg can be used as the anti-androgen component of feminising hormone therapy.

What are the side effects of Siterone?

The most commonly reported side effects of using Siterone tablets 50 mg in men is breast tenderness, breast pain (gynaecomastia) and inhibition of sperm production, leading to temporary infertility. In women ovulation is inhibited and there may be some breast discomfort. Other side effects include tiredness and diminished vitality, temporary inner restlessness or depressive moods, and changes in body weight.

When should Siterone not be used?

You should not use Siterone tablets 50 mg if you:

• are allergic to cyproterone or any ingredients in Siterone
• are pregnant or breastfeeding
• have liver disease or jaundice
• have deep venous thrombosis, thromboembolic disorders or cerebral vascular accident
• are a diabetic taking antidiabetics or insulin, without discussion with your doctor, as Siterone may affect your glucose tolerance

How should Siterone be taken?

You should take your Siterone 50 mg tablets once or twice a day, depending on what you are being treated for and the recommendations of your doctor and may be for several days or weeks in men. Women should take 1 or 2 tablets a day at the same time each day, for the first 21 days of the menstrual cycle, followed by 7 tablet-free days, to allow withdrawal bleeding to occur.

How long should you take Siterone?

You should take your Siterone tablets 50 mg once or twice a day after a morning and evening meal, for as long as your doctor recommends, which may be a few days or several weeks in men, depending on what you are being treated for. In women you will usually take your Siterone 50 mg tablets for the first 21 days of the menstrual cycle, followed by 7 tablet-free days, to allow withdrawal bleeding to occur.

Missed dose of Siterone

If you miss a dose of Siterone tablets 50, take it as soon as you remember, unless it is time to take the next dose, then skip the missed dose. Do not take a double dose.

How should product name be stored?

Keep your Siterone tablets 50 mg in the pack until used. Store at room temperature below 25°C, keep away from direct sunlight.