Histrelin - Subcutaneous

Histrelin is used for children to treat central precocious puberty. It is a condition in which a child's physical signs of sexual maturity (e.g. breast growth, appearance of underarm or pubic hair, menstruation) develop at an unusually early age.

Histrelin is available as an implant (contained inside a tiny cylinder that looks like a small, thin and flexible tube) that is usually inserted into the inner part of the upper arm.

The doctor will insert the implant for your child through minor surgery. Your child will be given a local anaesthetic before his/her doctor makes a small cut and places the implant under the skin. The cut may be closed with stitches or surgical strips and covered with a bandage.

After implant insertion, you should keep your child's arm clean and dry and should avoid bathing and swimming for 24 hours. Your child must also avoid heavy lifting or any activity that may affect the implant in the arm for 7 days.

It may take some time for Histrelin to take effect. This is because the medicine is being released slowly from the site of insertion. This slow release means that the implant lasts longer and there will be no need to replace it so often. Your child's doctor will advise you on the course of treatment or when to remove or replace the implant.

Ensure that you keep all your child's appointments with his/her doctor so that the implant is replaced on time. The doctor also needs to regularly monitor your child's response to Histrelin.

If your child misses an appointment, alert your doctor. A new appointment should be scheduled as soon as possible.

Alert the doctor immediately if your child is pregnant or may be pregnant.

Inform your doctor if your child has the following conditions:

• mood disorders
• depression
• history of fits or seizures
• brain disease or tumour
• osteoporosis

If your child needs to undergo diagnostic tests for certain hormones, inform the doctor that he/she is on Histrelin treatment.

Why is it important to keep my child's appointments with the doctor?

Keep your child's appointments with his/her doctor. The doctor needs to monitor your child's condition and check his/her response to the medication regularly.

• Certain diagnostic tests to confirm central precocious puberty may be needed before treatment, to know if this medicine is suited for your child.
• The implant may be accidentally expelled from the insertion site with or without your child knowing it. The doctor may need to occasionally check on the implant site.
• Routine tests (e.g. certain hormone levels) may be done while your child is being treated with Histrelin. The doctor will advise you about how often your child needs to have these tests.
• Regular monitoring of height and assessment of bone age may also be needed.

Histrelin may cause any of the following side effects: implant site reactions such as bruising, soreness, redness, pain, tingling, itching, or swelling.

Some side effects may need immediate medical help. Alert your child's doctor quickly if your child experiences any of the following:

• fits or seizures
• unusual changes in mood or behaviour (being too depressed, agitated, restless, irritable, angry, aggressive, or having thoughts of self-harm)
• dizziness, headache, upset stomach, eye pain, blurred or double vision, loss of eyesight, ringing in the ears

Inform your child's doctor if any of these side effects do not go away or are severe, or if he/she experienced other side effects.

Always notify your child's doctor and pharmacist if he/she is taking or using any other medicines, including herbal tonics such as traditional Chinese medicines, supplements, and medicines that you buy without a prescription.

Store in the refrigerator, between 2-8°C. Do not allow Histrelin to freeze. If frozen, this medicine will become ineffective and should not be used.

Keep the implant in their original package to protect from light.

Medicines must not be used past the expiry date.