Zoladex

About Zoladex

Zoladex contains a medicine called goserelin. This belongs to a group of medicines called GnRH analogues (synthetic hormones).

In women, Zoladex works by reducing the amount of oestrogen (a hormone) produced by the body. It does this by bringing on a temporary medical menopause.

Why we recommend it

We recommend Zoladex for the following reasons.

• To shrink fibroids before surgery for fibroids. (This can be open or keyhole surgery.)
• To shrink the size of your womb (uterus) before a hysterectomy.
• To control symptoms of heavy painful periods until surgery (when all other medical treatment has been unsuccessful).
• To treat endometriosis. This is a condition where cells normally only found in the lining of your womb (uterus) are found elsewhere in your body. For example, on other structures near your womb.
• To treat PMS (premenstrual syndrome).
• To treat infertility.
• To treat breast cancer.
• For any other gynaecological condition where inducing a temporary medical menopause may be considered beneficial by your doctor.

Your gynaecological team will have told you the reason why we recommend Zoladex for you. Speak to them if you have further questions.

Restrictions on using Zoladex

We do not give Zoladex to patients who are:

• allergic to goserelin or the other ingredients (lactide/glycolide copolymer) contained in this medicine
• pregnant or breastfeeding (see ‘Pregnancy and breastfeeding’ below)
• trying to get pregnant (unless we recommend Zoladex as part of infertility treatment).

Pre-existing conditions

You must let us know if you have any of the following conditions.​​​​

• High blood pressure. Zoladex can raise or lower blood pressure.
• Any heart or blood vessel conditions including heart rhythm problems (arrhythmia or QT prolongation), or are being treated with medicines for these conditions. Zoladex can heighten the risk of heart rhythm problems and cause increased palpitations or dizziness and fainting. 
• Any condition that affects the strength of your bones. This is especially important if you:
  • are a heavy drinker
  • are a smoker
  • have a family history of osteoporosis (a condition that affects the strength of your bones)
  • have a poor diet
  • take anticonvulsants (medicines for epilepsy or fits) or corticosteroids (steroids).
• Depression, for which you are taking medicines. Zoladex can cause severe depression. 
• A tumour of the pituitary gland. Zoladex can make the tumour bleed or collapse, causing severe headaches, sickness, loss of eyesight and unconsciousness. This side effect is rare. Go to your nearest Emergency Department (A&E) if this happens.
• Diabetes. Zoladex can raise blood sugar levels. Check your blood sugar levels and speak to your GP if they are higher, so they can adjust your medicine levels.

Use with other medicines

Let us know about any medicines you are taking, or are about to start taking. This includes anything you buy without a prescription, and herbal medicines.

• Zoladex can interfere with some heart rhythm medicines (for example quinidine, procainamide, amiodarone and sotalol).
• Zoladex can increase the risk of heart rhythm problems when used with other drugs. These include methadone (for pain relief and drug addiction detoxification), moxifloxacin (antibiotic), and some antipsychotics (for serious mental illnesses).

About treatment with Zoladex

How we give it

Each Zoladex implant comes as a small cylindrical pellet in a special syringe and needle. The pellet is about the size of a grain of rice and contains 3.6mg of goserelin. 

The pellet slowly dissolves and releases the medicine. This takes about 28 days.

We inject it under the skin on your belly (stomach), usually below your belly button, on the right or left side. We do this every 28 days, until we have given you your prescribed number of doses.

Doses

The number of doses depends on the condition we are treating.

Pre-surgery use

For use before surgery, the usual dose is 2 or 3 injections.

Control of symptoms

For use to control symptoms, the dose is anything between 6 to 18 injections. If we recommend more than 6 doses, we will explain the possible side effects to you (for example thinning of bones) and discuss preventative treatment.

• We often recommend hormone replacement therapy (HRT), and we will discuss this with you. HRT is particularly recommended if you take Zoladex for more than 6 months, because it protects against bone loss and osteoporosis (weak bones).

Follow-up appointments between doses

We will offer you a follow-up appointment every 28 days. This will take place by telephone or in clinic. During this appointment, we will review any symptoms that you experience.

It is important that you attend these follow-up appointments between every dose.

Rescheduling your follow-up

If you cannot make your scheduled appointment, contact us to move your appointment to a date before or after the scheduled one. This must take place a maximum or 3 days before or after the scheduled appointment.

• If you make an appointment that is 3 days earlier, it is safe to take your Zoladex. (There is no risk of overdose).
• If you delay your appointment for longer than than 3 days, your symptoms may return and you may experience vaginal bleeding.

Side effects

Many of the common side effects listed below will be mild and go away after a short time.

If they continue, or you experience other side effects that are worrying you, get in touch with the Gynaecology Admin Team. They can arrange a follow-up appointment. 

Common

• Your periods will stop. The timing of this varies, but it often happens after the second injection. You may have some irregular bleeding before they stop completely.
• Many patients experience symptoms of menopause. These include:
  • hot flushes and sweats
  • mood changes including low mood
  • headaches
  • change in libido (sexual drive)
  • change in breast size
  • dry vagina
  • hair loss
  • acne
  • weight gain
  • joint pain.​​​

These side effects often happen after 3 or 4 doses, so are more common in women who have a longer duration of treatment. 

Rare