1 What is Antagon?

Generic: Ganirelix (Subcutaneous Route)

Antagon is a gonadotropin-releasing hormone (GnRH) antagonist, which is used as a fertility medicine to prevent premature luteinizing hormone (LH) surges or ovulation in women undergoing fertility treatment of controlled ovarian hyperstimulation. 

This medicine may also help to reduce the need for follicle-stimulating hormone (FSH), which is also needed for ovulation. 

This drug is available in solution form only with your doctor's prescription. 

2 What to Know Before Using

Before using Antagon, you must know all about the risks and complications associated with it.

If you are about to start a drug therapy, the risk-benefit ratio of taking the drug should be considered carefully. Here, the suitable drug therapy is chosen by the doctor with active participation of the patient. 

There are some important factors such as drug interactions, metabolic impairment, hypersensitivity reaction, pregnancy, lactation etc. which may alter the desired therapeutic effects of such medications. 

Sometimes the presence of other health disorders affects the beneficial effects of this medicine and even may cause serious toxic effects. If you have had any allergic reactions to any medicine then you must inform your doctor about that. 

Further, you should tell your doctor if you have any other medical problems, especially:

Certain drugs should not be used concurrently with such medications. It is always recommended to consult with your doctor if you are in need of some other medications or even any over-the-counter medicine for another health problem in order to avoid unwanted toxic effects.

Studies in animals or pregnant women have demonstrated positive evidence of fetal abnormalities. This drug should not be used in women who are or may become pregnant because the risk clearly outweighs any possible benefit.

3 Proper Usage

You should use Antagon following the directions given by your doctor. The dosage schedule and the duration of drug therapy depend on the particular medical problem for which you are using this medicine. The therapeutic dose may also vary with the patient’s condition or requirement and the strength of the medicine as well.

For the treatment of female infertility, 250 µg of ganirelix is injected subcutaneously once a day during the mid to late follicular phase (about 7th or 8th day up to 12th or 13th day of menstrual cycle) after receiving FSH treatment on 2nd  or 3rd day of menstrual cycle. 

Sometimes ganirelix injection can be given at home. If you are using this medicine at home:

  • You should understand the proper use as well as the method of safely preparing the medicine.
  • You must wash your hands with soap and water and use a clean work area to prepare your injection.
  • Make sure you clearly understand and carefully follow your doctor's instructions on how to give yourself an injection, including using the proper needle and syringe.

Further, it is advised to store the medicine in a closed container at room temperature away from heat, moisture, and direct light. All kinds of medicines should be kept out of the reach of children. However, outdated medicines should be disposed by an appropriate way.

4 Precautions to Take

Before using Antagon, there are some precautions you must take.

Firstly, regular visits to your doctor are recommended to check that this medicine is working properly or not. Additionally, the following guidelines should be followed while receiving this medicine:

  • Serious types of allergic reactions including anaphylaxis have been reported in some individuals undergoing such drug therapy. Anaphylaxis is a life-threatening medical condition which requires immediate medical attention. Thus, you should never late to call a doctor if you have developed a skin rash, itching, hoarseness of voice, troubled breathing, difficulty in swallowing, or any swelling of your hands, face, or mouth while you are using this medicine.
  • Your doctor may ask you to record your basal body temperatures (BBTs) daily. This BBT record will help your doctor to determine the time when you are most fertile and when ovulation occurs. It is important that sexual intercourse take place around the time when you are most fertile to give you the best chance of becoming pregnant.
  • Additionally, an ultrasound examination and measurement of certain hormones can be done by your healthcare professional to assess the condition of the ovary.
  • If severe abdominal pain occurs with use of ganirelix, discontinue receiving this medicine and report the problem to your doctor immediately.

5 Potential Side Effects

As with many medications, there are several potential side effects associated with Antagon. These side effects usually go away during the treatment episode as your body adjusts to the medicine. 

Your healthcare professional may advise you about the ways how to prevent or reduce those unwanted side effects. Sometimes you may need to consult with the doctor if you notice any of the following toxic effects, especially:

  • Abdominal or stomach pain
  • Bloating
  • Cough
  • Difficulty with swallowing
  • Dizziness
  • Diarrhea
  • Fast heartbeat
  • Headache
  • Puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • Rapid weight gain
  • Redness, pain, or swelling at the injection site
  • Shortness of breath
  • Skin rash, hives, or itching
  • Tightness in the chest
  • Unusual  tiredness or weakness

Other side effects not listed may also occur in some patients. If you notice any other effects, you should check with your healthcare professional right away.

6 Related Clinical Trials