How does this medication work? What will it do for me?

Ganirelix belongs to the class of medications known as gonadotropin-releasing hormone (GnRH) antagonists. It is used to prevent premature ovulation in women undergoing ovarian stimulation as part of fertility treatment. It blocks the effects of gonadotropin-releasing hormone (GnRH).

GnRH controls the secretion of another hormone, called luteinizing hormone (LH), a hormone that starts ovulation (release of an egg) during the menstrual cycle. Ganirelix allows the release of an egg to be controlled so it is released at the best time for pregnancy to occur.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Each prefilled syringe of clear, colourless, sterile, ready-to-use solution contains ganirelix 250 µg. Nonmedicinal ingredients: acetic acid and/or sodium hydroxide to adjust pH, glacial acetic acid, mannitol, and water for injection.

How should I use this medication?

The usual dose of ganirelix is 250 µg injected once daily under the skin. The length of treatment is usually about 5 days, but can range from 1 to 19 days. Ganirelix should be injected under the skin of the upper thigh, as directed by your doctor.

A health care professional will show you how to use this medication properly. Read the patient information leaflet carefully and ask your doctor any questions you may have.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to use this medication exactly as prescribed by your doctor. If you miss a dose, administer it as soon as possible. If you are more than 6 hours late (i.e., the time between 2 injections is longer than 30 hours), give the dose as soon as possible and contact your doctor for further instruction. Do not inject a double the dose to make up for a missed dose. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature between 15°C and 30°C, protect it from light, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not use this medication if you:

  • are allergic to ganirelix, gonadotropin-releasing hormone (GnRH), other GnRH-related hormones, or any of the ingredients of the medication or the container (such as latex)
  • are or may be pregnant
  • have moderate-to-severe liver or kidney function impairment

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • dizziness
  • generally unwell feeling
  • headache
  • lack or loss of strength or energy
  • nausea
  • redness, swelling, or irritation at the place of injection

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • abdominal discomfort or pain, nausea, diarrhea, difficulty breathing

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Allergic reactions: If you have active allergies, talk to your doctor about the risks and benefits of using this medication.

Latex allergy: The packaging of this medication contains rubber latex. If you have a latex allergy, talk to your doctor before using this medication.

Ovarian Hyperstimulation Syndrome (OHSS): During or following treatment with ganirelix, a rare condition called ovarian hyperstimulation syndrome (OHSS) may develop. With OHSS, too many follicles grow and can cause abdominal discomfort or pain, nausea, diarrhea, rapid weight gain, decreased urination, and sometimes difficulty breathing. If you experience any of these symptoms, contact your doctor immediately.

Pregnancy: This medication should not be used during pregnancy. See the section, "Who should not take this medication."

Breast-feeding: It is not known if ganirelix passes into breast milk. Women who are breast-feeding should not take ganirelix.

Children: The safety and effectiveness of using this medication has not been established for children.

Seniors: The safety and effectiveness of using this medication has not been established for seniors.

What other drugs could interact with this medication?

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.