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a synthetic compound derived from, and an antagonist to, gonadotropin-releasing hormone; used as the acetate salt to inhibit premature luteinizing hormone (LH) surges in women undergoing ovarian hyperstimulation in the treatment of female infertility, administered subcutaneously.


(ga-ni-rell-ix) ,


(trade name)


Therapeutic: hormones
Pregnancy Category: X


As a component of infertility regimens (with recombinant follicle stimulating hormone [FSH], and human chorionic gonadotropin) to inhibit premature luteinizing hormone (LH) surges in patients undergoing controlled ovarian hyperstimulation.


Induces a rapid, reversible suppression of gonadotropin (FSH and LH) secretion, which suppresses surges in LH. Ganirelix is a gonadotropin-releasing hormone antagonist.

Therapeutic effects

Suppression of LH surges increases the implantation and pregnancy rates in patients undergoing in vitro fertilization.


Absorption: Well absorbed following subcutaneous administration.
Distribution: 44 L.
Metabolism and Excretion: Metabolized to two primary metabolites; 18% excreted unchanged in urine.
Half-life: 16 hr.

Time/action profile (blood levels)

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Contraindicated in: Hypersensitivity to ganirelix, gonadotropin releasing hormone or any of its analogs; Obstetric: Known or suspected pregnancy.
Use Cautiously in: None noted.

Adverse Reactions/Side Effects


  • ovarian hyperstimulation syndrome (life-threatening)
  • abdominal pain
  • nausea


  • pelvic pain
  • vaginal bleeding


  • hypersensitivity reactions (life-threatening)
  • injection site reactions


Drug-Drug interaction



Subcutaneous (Adults) 250 mcg once daily during the mid-to-late follicular phase of menstrual cycle after initiating FSH on day 2 or 3 of cycle. Treatment with ganirelix should be continue daily until day of administration of human chorionic gonadotropin (when adequate follicular response achieved).


Injection: 250 mcg/0.5 mL in prefilled syringes

Nursing implications

Nursing assessment

  • Assess patient for pregnancy prior to therapy. Therapy should not be initiated if patient is pregnant.
  • Lab Test Considerations: May cause elevated neutrophil counts and decreased hematocrit and total bilirubin concentrations.

Potential Nursing Diagnoses

Deficient knowledge, related to medication regimen (Patient/Family Teaching)


  • Subcutaneous: Administer via subcutaneous injection only.

Patient/Family Teaching

  • Instruct patient on correct technique for subcutaneous injection. Most convenient sites are in the abdomen around the navel and in the upper thigh.

Evaluation/Desired Outcomes

  • Successful in vitro fertilization procedure.


/gan·i·re·lix/ (gan″ĭ-rel´iks) a synthetic decapeptide derived from, and an antagonist to, gonadotropin-releasing hormone; used as the acetate salt in the treatment of female infertility.


a gonadotropin-releasing hormone antagonist.
indications It is used to inhibit premature luteinizing hormone surges in women undergoing controlled ovarian hyperstimulation.
contraindications Pregnancy, lactation, latex allergy, and known hypersensitivity to this drug prohibit its use.
adverse effects Fetal death is a life-threatening consequence of this drug's use. Other adverse effects include headache, ovarian hyperstimulation syndrome, gynecological abdominal pain, nausea, and pain on injection. Common side effects include spotting and breakthrough bleeding.
References in periodicals archive ?
Polycystic ovarian syndrome (PCOS) patients have a favorable response to ganirelix acetate during controlled ovarian hyperstimulation (COH) for in vitro fertilization (IVF)-embryo transfer (ET).
Serono (virt-x SEO and NYSE: SRA) - In the first clinical trial to directly compare gonadotropin releasing hormone (GnRH) antagonists, patients using Cetrotide(R) (cetrorelix acetate for injection) required fewer injections compared to patients using Ganirelix Acetate (formerly known as Antagon(TM) Injection) to prevent premature ovulation during infertility treatment.
Cetrotide(R) offers patients a similar safety profile as well as similar efficacy compared to Ganirelix Acetate, but Cetrotide(R) has the added benefit of significantly fewer injections.
7%) required one injection while most of the patients who used Ganirelix Acetate (62.
Currently approved treatments for infertility: clomiphene citrate, follicle-stimulating hormones, human menopausal hormones, Schering-Plough's Ganirelix, Merck Serono's Ovidrel.
First established pregnancy after controlled ovarian hyperstimulation with recombinant follicle stimulating hormone and the gonadotrophin releasing hormone antagonist ganirelix (Org 37462).
At a leading follicle diameter of 14 mm, ganirelix administration was resumed until the final oocyte maturation was induced by 10,000 IU hCG.
A randomized prospective study of microdose leuprolide versus ganirelix in in vitro fertilization cycles for poor responders.
Ganirelix for luteolysis in poor responder patients undergoing IVF treatment: a Scandinavian multicenter 'extended pilot study'.
The agreement follows a period of preliminary research to confirm that Syntex's investigational drug, ganirelix is compatible in the ATRIGEL(TM) System and that the System will provide sustained release of the drug for up to one month.