Antagon Injection®
Brand Name: Antagon Injection®
Active Ingredient:   ganirelix acetate
Strength(s): 250 mcg/0.5 ml
Dosage Form(s):   Injection
Company Name:    Organon, Inc.
Availability:         Prescription only
*Date Approved by the FDA:   July 29, 1999
*Approval by FDA does not mean that the drug is available for consumers at this time.
What is Antagon? Antagon is used to inhibit premature ovulation in women undergoing fertility procedures.

Who should not use Antagon?

  • Women who have experienced a hypersensitivity reaction to gonadotropin-releasing hormone (GnRH) or any other GnRH-type drug.
  • Women who suspect or know they are pregnant.

Special Warnings with Antagon:

  • A physician specializing in fertility treatment should prescribe Antagon.
  • Before starting treatment with Antagon, pregnancy must be ruled out.

General Precautions with Antagon:

  • Patients with hypersensitivity to GnRH should be closely monitored after the first injection.
  • The packaging of Antagon contains natural rubber latex that may cause allergic reactions.
  • You will need to be examined on a regular basis when using Antagon.

What should I tell my doctor or health care provider?

Tell your doctor if you are pregnant or breast-feeding. Women who are pregnant or breast-feeding should not use Antagon.

What are some possible side effects of Antagon? (This is NOT a complete list of side effects reported with Antagon. Your health care provider can discuss with you a more complete list of side effects.)  

The most frequent side effects of Antagon are:

  • Abdominal pain
  • Fetal death
  • Headache

For more detailed information about Antagon, ask your health care provider.

Link to Antagon's label

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Posted: 5/2/00
Updated: 10/31/00, 12/29/04ghc