Ganirelix

Summary

Ganirelix is a synthetic decapeptide GnRH antagonist used in assisted reproductive technology (ART) to prevent premature LH surges in women undergoing controlled ovarian hyperstimulation (COH). It rapidly suppresses gonadotropins without initial flare effect, allowing precise timing of oocyte retrieval.

Mechanism of Action

Competitively and reversibly blocks GnRH receptors in the pituitary gland, suppressing the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), thereby preventing premature LH surges during controlled ovarian hyperstimulation.

Routes of Administration

Goals & Uses

• Reduction of ovarian hyperstimulation syndrome (OHSS) riskSafety In ARTModerate
• Treatment of endometriosisGynecologyLow
• Controlled ovarian hyperstimulation for IVFAssisted Reproductive TechnologyHigh
• Prostate cancer (androgen deprivation)OncologyLow
• Prevention of premature LH surge during COHReproductive EndocrinologyHigh

Contraindications

• Severe renal or hepatic impairmentOrgan ImpairmentModerate
• Hypersensitivity to ganirelix or any componentAllergyHigh
• PregnancyPopulationHighPotential fetal risk or insufficient safety data
• Known hypersensitivity to GnRH or GnRH analogsAllergyHigh

Adverse Effects

• Injection site reactionsLocalCommon
• Hypersensitivity/anaphylaxisImmunologicalRare
• HeadacheNeurologicUncommonPain in the head or upper neck
• Abdominal pain/pelvic painGastrointestinal/reproductiveCommon
• NauseaGastrointestinalUncommonFeeling of sickness or urge to vomit
• Ovarian hyperstimulation syndrome (OHSS)ReproductiveUncommon

Drug Interactions

• Human Chorionic Gonadotropin (hCG)Low
• Gonadotropins (FSH, hMG)Low
• GnRH agonistsHigh

Population Constraints

• PregnancyReproductive SafetyAbsolute
• Hepatic impairmentOrgan FunctionRelative
• Renal impairmentOrgan ImpairmentRelative
• Pediatric patientsAgeAbsolute
• Postmenopausal womenReproductive StatusAbsolute

Regulatory Status

• European UnionApprovedApproved: Prevention of premature LH surges in women undergoing controlled ovarian stimulationApproved as Orgalutran by EMA; widely used in European ART clinics.
• United StatesApprovedApproved: Inhibition of premature LH surges in women undergoing controlled ovarian hyperstimulationOriginally approved as Antagon (1999); brand discontinued but generics available.
• United KingdomApprovedApproved: Prevention of premature LH surges in women undergoing controlled ovarian stimulationAvailable as Orgalutran; approved prior to and maintained post-Brexit under MHRA.

Approved by the FDA in 1999 (Antagon) and by the EMA (Orgalutran). The original brand name Antagon was discontinued in the US market; generic formulations are available.

Evidence & Sources

No sources recorded yet.