FIRMAGON 80MG POWDER

What is this medicine for?

FIRMAGON is a hormone therapy for prostate cancer. Prostate cancer often grows in response to the male hormone testosterone. FIRMAGON blocks the signal that tells your body to make testosterone, causing testosterone levels to drop very quickly to 'castrate levels' — levels low enough to slow or stop prostate cancer growth.

Unlike older hormone injections (GnRH agonists like triptorelin or leuprolide), FIRMAGON does NOT cause an initial testosterone surge ('tumour flare') that can temporarily worsen symptoms. It works immediately — testosterone drops within 3 days.

How is it given?

First month (loading doses):

Two injections are given on day 1 — one on each side of your abdomen (subcutaneously). These larger starting doses rapidly bring testosterone down to castrate levels (240 mg administered as two 120 mg (3 mL) injections).

Every month after that (maintenance doses):

Subcutaneous: 80 mg administered as one 4 mL injection every 28 days (beginning 28 days after initial loading dose).

This keeps testosterone suppressed long-term. Keep all monthly injection appointments — missing a dose allows testosterone to rise, which can allow the cancer to progress.

What side effects might I notice?

Very common:

•       Injection site reactions — redness, swelling, pain, or a lump at the injection site (very common after starting doses; usually resolves in a few days)

•       Hot flushes — caused by low testosterone; a sign the treatment is working

•       Weight gain

Common:

•       Fatigue, mild fever (especially at the start)

•       Night sweats and muscle/joint pain

•       Reduced sex drive and erectile difficulties — expected due to low testosterone

•       Mild breast tenderness or enlargement

Long-term effects of testosterone suppression:

•       Bone thinning (osteoporosis) — take calcium and Vitamin D supplements as prescribed; bone density scans will be arranged

•       Metabolic changes — weight gain, raised blood sugar, changes in cholesterol

•       Possible effects on heart rhythm — your doctor will monitor your ECG

Important safety information

Frequently Asked Questions

❓ How is FIRMAGON different from other prostate cancer hormone injections?

Older hormone injections (GnRH agonists) initially cause a testosterone surge for 1–2 weeks before suppressing it — this can temporarily worsen bone pain or other symptoms. FIRMAGON blocks the hormone signal immediately, so testosterone drops within 3 days with no initial surge. This means no anti-androgen tablets are needed at the start, which is simpler and safer.

❓ Why were two injections given on the first day?

The two larger starting injections rapidly fill up and block the hormone receptors, bringing testosterone down quickly. After that, one smaller monthly injection is enough to keep testosterone suppressed. Think of the starting doses as filling a tank, and the monthly doses as keeping it full.

❓ What can I do about hot flushes?

Hot flushes are common on hormone therapy. Helpful approaches include: wearing light clothing, keeping environments cool, and avoiding triggers like spicy food and alcohol. Acupuncture has good evidence for this specific side effect. Your doctor can also prescribe medicines such as low-dose venlafaxine if flushes are severe.