Ganirelix injection essentially prevents premature ovulation from occurring. By blocking the release of luteinizing hormone (LH) in the body, the medicine stops an egg from releasing too soon from the ovary, allowing it time to properly develop.
Using this medicine may also reduce the need for follicle-stimulating hormone (FSH), a hormone that controls egg production in the ovaries.
While this medicine treats certain causes of infertility in women, it must not be used to treat a woman who is already pregnant.
Ganirelix is supplied as a solution for injection. In the US, it is sold under the brand name, Antagon, and is sold to patients through a doctor's prescription only.
Most, if not all, prescription medicines cause side effects. Ganirelix may cause side effects which are expected and required as the medicine works in the body. Other side effects are unwanted and may or may not require medical attention.
Serious allergic reaction
The medicine may cause a serious type of allergic reaction called anaphylaxis. Call your doctor immediately if this occurs. Symptoms of this condition are as follows:
A condition known as ovarian hyperstimulation syndrome (OHSS) may result from using this injection. It may occur during or after treatment.
Though rare, a serious case of OHSS causes the following side effects that may be life-threatening. Seek urgent medical attention if you experience any of them.
Call your doctor immediately if you notice any of the side effects on the following list:
Less commonly occur
The following side effects may occur, but do not usually require medical attention. They tend to go away on their own as the body gets used to the medicine. Tell your doctor if any of them occur but gets worse, bothers you, or does not go away.
Less commonly occur
All of the listed side effects may not occur, or may not occur all at the same time. Some patients may experience other side effects which are not listed here.
Also check with your doctor if you notice any unusual symptom that becomes bothersome or does not go away. You can ask your doctor or health care professional about ways to prevent or reduce side effects.
You may also call the FDA at 1-800-FDA-1088 to report side effects
Ganirelix is supplied as a disposable, pre-filled glass syringe containing 250 mcg/0.5 mL of solution for injection. A sterilized needle is attached and covered with a rubber cap.
Ganirelix injection may be given to you by a nurse or healthcare professional at a hospital or medical clinic. You may also be given the medicine to inject at home.
Carefully read the patient information leaflet that should be given to you, as well as the prescription label.
Your doctor will instruct you on how to prepare and take the injection. If you are not clear on what to do, ask your doctor, pharmacist or healthcare professional to explain.
The following guide may be helpful:
The following is an average dosage guide. You should not change your dose to suit this guide. All changes in your dose must be done by your doctor.
For treatment of infertility in women
Adults: After treatment with follicle-stimulating hormone (FSH), and on day 2 or 3 of your menstrual period, inject 250 micrograms (mcg) of Ganirelix under your skin.
Take this dose once a day during the mid to late follicular phase. This will be around Day 7 or 8 up to Day 12 or 13 of your menstrual cycle.
Children: Ganirelix is not indicated for use in children.
If you missed your dose of Ganirelix injection, call your doctor or healthcare professional for instructions.
No data is available relating to overdose in patients using this medicine.
Food, alcohol, and tobacco
Eating during the time of taking a medicine or eating certain foods may cause interaction. The use of alcohol or tobacco may also cause interaction. Your doctor may caution you on the use of foods, alcohol or tobacco if necessary.
Adequate studies have not been done to determine if Ganirelix interacts with other medicines used by patients during treatment with the injection.
This does not mean that no other medicines may interact. Necessary precautions still need to be taken when patients are taking the injection and using other medications.
Tell your doctor about all prescription or over-the-counter medicines (OTC's), vitamins, or herbal supplements you take or plan to take.
Certain medical conditions may affect or be affected by the use prescription medicines. You must tell your doctor if you are pregnant. Due to the risk of harm to an unborn baby, your doctor should not treat you with this medicine during pregnancy.
Keep the medicine in a closed container, away from heat, moisture, and direct light. Keep from freezing.
Keep the medicine out of the reach of children.
Throw away medicine that is expired or no longer needed.
Used syringes and needles should be placed in a hard container. Close the container and keep it away from children and pets.
You may ask your healthcare professional or local waste disposal agency how to safely dispose of unused medicine, needles, and syringes.
Ganirelix is a safe and effective medicine for preventing premature ovulation in adult women receiving controlled ovarian hyperstimulation fertility therapy.
However, this medicine is not safe for use in pregnant women due to the risk of harm to an unborn child.
There are not many side effects caused by using the injection. There is also no known adverse interaction caused by using Ganirelix together with other medicines. It does not mean that there is no possibility for adverse interaction. Therefore, precautions may still need to be taken when treating patients with this fertility medicine.
While side effects are few, the medicine is known to cause a serious, possibly life-threatening, allergic condition known as anaphylaxis. In addition, and although rare, another life-threatening condition called ovarian hyperstimulation syndrome (OHSS) has occurred in patients.
Despite the potential for these adverse effects, patients have become pregnant by using Ganirelix. Multiple births have occurred in some case.