Histrelin Implant

Histrelin implant is used to treat children with central precocious puberty (CPP; a condition causing children to enter puberty too soon, resulting in faster than normal bone growth and development of sexual characteristics). Histrelin implant is in a class of medications called gonadotropin-releasing hormone (GnRH) agonists. It works by decreasing the amount of certain hormones in the body.

Histrelin comes as an implant to be inserted subcutaneously (under the skin) in the upper arm by a doctor or nurse in a medical office or clinic. It is inserted every 12 months. After 12 months, the implant is removed and may be replaced with another implant to continue treatment.

The doctor will use a medication to numb the arm, make a small cut in the skin, then insert the implant just under the skin. The cut will be closed with stitches or surgical strips and covered with a bandage. Keep the area around the implant clean and dry for 24 hours after insertion. Do not swim or bathe during this time. Leave the bandage in place for at least 24 hours. If surgical strips are used, leave them on until they fall off on their own. Avoid heavy lifting and physical activity (including heavy play or exercise for children) with the treated arm for 7 days after receiving the implant. Avoid bumping the area around the implant for a few days after insertion.

Sometimes histrelin implant is hard to feel under the skin so the doctor may have to use certain tests, such as ultrasound or MRI scans (radiology techniques designed to show the images of body structures) to find the implant when it is time to remove it. Occasionally, histrelin implant may come out through the original insertion site on its own. You may or may not notice this happening. Call your doctor right away if you think this may have happened to you.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Before receiving histrelin implant,

• tell your doctor or pharmacist if you are allergic to this drug, any part of this drug, or any other drugs, foods or substances. Tell your doctor or pharmacist about the allergy and what symptoms you had.
• Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take.
• tell your doctor if you have or have ever had skin problems, seizures, brain or blood vessel problems or tumors, or mental illness.
• you should know that histrelin is not to be used in women who are pregnant or can become pregnant. Tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you think you have become pregnant while receiving histrelin implant, call your doctor immediately. Histrelin implant can harm the fetus.

Unless your doctor tells you otherwise, continue your normal diet.

If you miss an appointment to receive an implant of histrelin or to have histrelin implant removed, call your healthcare provider right away to reschedule your appointment.

Histrelin implant may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• bruising, pain, soreness, tingling, itching, or swelling at or around the place where implant was inserted
• scarring at the place where implant was inserted
• crying, irritability, impatience, anger, or aggressive behavior

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

• bleeding at the place where implant was inserted
• rash; itching; acne; blisters of sores in your mouth; dry, peeling, or blistering skin; muscle or joint aches; redness or swelling of your face, hands, or soles of your feet; fever; or swollen glands
• headache; ringing in the ears; eye pain, blurred vision, double vision, decreased vision, or other eye problems; dizziness; nausea
• seizures

Histrelin implant may cause new or worsening symptoms of sexual development during the first few weeks after the insertion of the implant. In girls receiving histrelin implant, light vaginal bleeding or breast enlargement may occur during the first month of treatment.

Histrelin implant may cause other side effects. Call your doctor if you have any unusual problems while receiving this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (https://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests and take certain measurements to check your body's response to histrelin implant.

Before having any laboratory test, tell your doctor and the laboratory personnel that you have a histrelin implant.

Ask your pharmacist any questions you have about histrelin implant.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.

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