Cetrotide

• Prevention of Premature LH Surge:
  Used in controlled ovarian stimulation during assisted reproductive technology (ART) cycles such as in vitro fertilization (IVF) to prevent premature luteinizing hormone (LH) surges and ovulation.
• Assisted Reproduction Protocols:
  Employed to improve oocyte retrieval rates by controlling timing of ovulation.
• Off-label Uses:
  Occasionally considered in managing hormone-sensitive cancers or other conditions requiring GnRH antagonism under specialist supervision.

• Route: Subcutaneous injection.
• Controlled Ovarian Stimulation:
  Typical dosage is 0.25 mg daily starting on day 5 or 6 of ovarian stimulation and continued until the day of human chorionic gonadotropin (hCG) administration.
• Alternate Protocol:
  Single-dose regimens of 3 mg or 3.75 mg may be used in some protocols.
• Pediatric and Elderly:
  Safety and efficacy not established.
• Renal/Hepatic Impairment:
  No dosage adjustments recommended; however, use caution due to limited data.

Cetrorelix acetate is a synthetic decapeptide GnRH (gonadotropin-releasing hormone) antagonist that competitively binds to pituitary GnRH receptors, immediately blocking endogenous GnRH action. This results in rapid suppression of pituitary secretion of LH and follicle-stimulating hormone (FSH), preventing premature LH surges during ovarian stimulation cycles. By controlling gonadotropin release, it allows synchronization of follicular development and optimizes timing of ovulation induction.

• Absorption:
  Rapid absorption after subcutaneous injection; peak plasma concentrations reached within 1 to 2 hours.
• Distribution:
  Volume of distribution approximately 80–100 L.
• Metabolism:
  Metabolized by peptide cleavage; no significant CYP450 involvement.
• Elimination:
  Primarily excreted by kidneys.
• Half-life:
  Approximately 5 to 10 hours, supporting once-daily dosing.

• Pregnancy:
  Category X — contraindicated due to its pharmacologic suppression of gonadotropins which can disrupt pregnancy maintenance.
• Lactation:
  Unknown if excreted in human milk; breastfeeding is not recommended during treatment.

• Gonadotropin-releasing hormone (GnRH) antagonist.

• Known hypersensitivity to cetrorelix or any excipients.
• Pregnancy or breastfeeding.
• Undiagnosed abnormal vaginal bleeding.

• Monitor for hypersensitivity reactions including anaphylaxis.
• Use with caution in patients with renal impairment.
• Possible local injection site reactions including erythema and swelling.
• Not intended for long-term use.
• Careful monitoring of ovarian response recommended to avoid ovarian hyperstimulation syndrome (OHSS).

Common:

• Injection site reactions (pain, erythema, swelling)
• Headache
• Nausea
• Abdominal pain

Less Common:

• Hot flashes
• Fatigue
• Dizziness

Rare/Serious:

• Hypersensitivity/anaphylactic reactions
• Ovarian hyperstimulation syndrome (OHSS)

• No significant CYP450 interactions known.
• Possible additive effects with other hormone-modulating agents; use caution.
• No known interactions with food or alcohol.

• Recent ART guidelines endorse cetrorelix as a first-line GnRH antagonist option for preventing premature LH surge in controlled ovarian stimulation.
• Emphasis on individualized dosing protocols and monitoring to reduce risk of OHSS.

• Store refrigerated at 2°C to 8°C (36°F to 46°F).
• Protect from light.
• Do not freeze.
• Keep vial in original packaging until use.
• After reconstitution (if applicable), use immediately or follow manufacturer’s specific instructions.
• Keep out of reach of children.