Orgalutran (Ganirelix)

Orgalutran is a GnRH antagonist that acts within the reproductive hormone pathway to control ovulation timing during assisted reproduction.

• Controlled ovarian stimulation (COS): prevents premature LH surge, allowing scheduled oocyte retrieval.
• In vitro fertilisation (IVF) cycles: supports synchronized follicular development for optimal embryo collection.
• Intracytoplasmic sperm injection (ICSI) cycles: aids timing of egg maturation to improve procedural success.

• Ganirelix competitively binds to pituitary gonadotropin‑releasing hormone (GnRH) receptors, blocking endogenous GnRH from stimulating the gland. This inhibition suppresses the release of luteinising hormone (LH) and follicle‑stimulating hormone (FSH), preventing an untimely LH surge during controlled ovarian stimulation and allowing precise control of follicular development.

Adverse reactions to Ganirelix are generally mild and reversible.

Common Side Effects

• Injection site erythema: redness at the injection site.
• Injection site pain: mild to moderate discomfort.
• Headache: transient headache.
• Nausea: occasional mild nausea.
• Fatigue: feeling of tiredness.
• Vaginal spotting: light spotting after administration.

Serious or Rare Side Effects

• Allergic reaction: rash, pruritus, or anaphylaxis.
• Severe abdominal pain: persistent or worsening abdominal discomfort.
• Ovarian hyperstimulation syndrome (OHSS): signs of fluid shift or rapid weight gain.
• Thromboembolic events: rare clot formation.
• Hypersensitivity: systemic allergic response requiring medical attention.

When using Ganirelix, clinicians should assess patient history and monitor response throughout treatment.

• Pregnancy testing: confirm absence of pregnancy before initiating therapy.
• Ovarian reserve assessment: evaluate baseline ovarian function.
• Monitoring LH levels: ensure adequate suppression during stimulation.
• OHSS risk evaluation: identify patients at high risk for ovarian hyperstimulation syndrome.
• Drug‑interaction review: check concomitant medications that may affect gonadotropin response.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Ganirelix may interact with other agents that influence the hypothalamic‑pituitary‑gonadal axis.

Major Interactions (Avoid)

• GnRH agonists: concurrent use can counteract antagonist effect.
• Hormonal contraceptives: may alter suppression dynamics.

Moderate Interactions (Monitor Closely)

• Gonadotropins (FSH, hMG): dose adjustments may be needed.
• Steroids used in IVF protocols: monitor for additive effects on hormone levels.
• Anticoagulants: observe for any changes in bleeding risk during oocyte retrieval.
• CYP‑mediated drugs: although Ganirelix is not extensively metabolised by CYP enzymes, observe for unexpected pharmacodynamic changes.
• Herbal supplements: assess for any impact on ovarian response.