Detirelix

Summary

Detirelix is a synthetic decapeptide GnRH antagonist developed in the 1980s–1990s. It was investigated for suppression of gonadotropins and sex steroids in conditions such as prostate cancer, endometriosis, and uterine fibroids. Unlike GnRH agonists, it blocks GnRH receptors directly, avoiding an initial testosterone/estrogen flare. Development was largely discontinued in favor of later-generation GnRH antagonists (e.g., cetrorelix, ganirelix) due to histamine-release side effects common to early GnRH antagonists.

Mechanism of Action

Competitively blocks GnRH receptors in the anterior pituitary, suppressing the release of LH and FSH, thereby reducing sex hormone production without an initial surge (flare effect).

Routes of Administration

Goals & Uses

• Controlled ovarian stimulation / ARTReproductive MedicineLow
• Treatment of endometriosisGynecologyLow
• Suppression of sex steroids for uterine fibroidsGynecologyLow
• Suppression of testosterone in prostate cancerOncologyLow

Contraindications

• PregnancyPopulationHighPotential fetal risk or insufficient safety data
• Hypersensitivity to GnRH or GnRH analoguesAllergy/immunologyHigh
• History of systemic mast cell disordersImmunologyHigh

Adverse Effects

• Local Injection Site ReactionsDermatologicalCommon
• Histamine-mediated systemic reactionsImmunologicUncommon
• Bone mineral density reductionMusculoskeletalUncommon
• Hypogonadal symptomsEndocrineCommon

Drug Interactions

• QT-prolonging drugsModerate
• Androgen deprivation therapy agentsModerate

Population Constraints

• Pediatric patientsAgeRelative
• Patients with hepatic impairmentOrgan FunctionRelative
• Patients with renal impairmentOrgan ImpairmentRelative

Regulatory Status

• European UnionUnapprovedNo EMA approval or marketing authorization; remained in research phase.
• United StatesUnapprovedInvestigational only; never submitted for or received FDA approval.
• United KingdomUnapprovedNo MHRA approval; not marketed in the UK.

Detirelix never received regulatory approval in any major jurisdiction. It remained an investigational/research compound and was not advanced to NDA/MAA filing. Development was superseded by cleaner GnRH antagonists.

Evidence & Sources

No sources recorded yet.