Choriogonadotropin Alpha

Approved Indications:

• Assisted Reproductive Technology (ART):
• Induction of final follicular maturation and ovulation in infertile women who have been pretreated with follicle-stimulating hormone (FSH) or human menopausal gonadotropin (hMG) as part of ART cycles (e.g., IVF, ICSI).
• Ovulation Induction in Anovulatory or Oligo-ovulatory Women:
• For women with ovulatory dysfunction who are candidates for gonadotropin therapy.
• Male Infertility (Delayed Puberty, Hypogonadotropic Hypogonadism) – off-label:
• As a part of treatment regimen to stimulate spermatogenesis (used in conjunction with FSH or hMG).

Off-Label / Clinically Accepted Uses:

• Cryptorchidism in Prepubertal Males:
• Used in select cases to stimulate testicular descent.
• Assessment of Leydig Cell Function:
• Single dose of hCG used diagnostically to assess testosterone response.

Dosage must be individualized based on indication, treatment phase, and prior ovarian stimulation protocol.

Women Undergoing Ovulation Induction or ART:

• Single subcutaneous injection of 250 mcg (equivalent to ~6,500–10,000 IU of urinary hCG) given 24–48 hours after last dose of FSH or hMG.
• Ovulation typically occurs 36–48 hours after injection. Intercourse or oocyte retrieval should be timed accordingly.

Off-Label Use in Men (Hypogonadotropic Hypogonadism):

• Choriogonadotropin Alpha is not typically used; instead, urinary hCG (e.g., 1,000–2,000 IU IM 2–3 times per week) is preferred.
• If used off-label: dosage conversion from IU to mcg must be carefully calculated under specialist supervision.

Administration Route:

• Subcutaneous injection only.
• Inject into abdomen or thigh; rotate injection sites.

Special Populations:

• Pediatrics: Use not approved for pediatric indications.
• Elderly: Not indicated.
• Renal/Hepatic Impairment: No dosage adjustment provided; use with caution.

Choriogonadotropin alpha is a recombinant form of human chorionic gonadotropin (hCG) produced using recombinant DNA technology in Chinese hamster ovary (CHO) cells. It mimics the natural luteinizing hormone (LH) surge by binding to LH/hCG receptors in the ovary, thereby triggering final maturation of ovarian follicles, resumption of meiosis, and luteinization. In men, hCG stimulates Leydig cells in the testes to produce testosterone, which indirectly supports spermatogenesis and sexual maturation.

• Absorption: Rapid after subcutaneous injection; peak plasma levels occur in approximately 12–24 hours.
• Bioavailability: High; comparable to urinary hCG (~40%–60% systemic exposure).
• Distribution: Vd not well characterized; binds to LH/hCG receptors primarily in ovaries and testes.
• Metabolism: Slowly degraded in the liver and kidneys; metabolism similar to endogenous hCG.
• Elimination: Excreted primarily via urine.
• Half-life: ~30–33 hours (longer than endogenous LH); supports prolonged biological activity.

• Pregnancy: Contraindicated in pregnancy. Category X under old FDA system due to no benefit and potential to harm fetal development.
• Lactation: Not intended for use during breastfeeding. There are no data on the excretion of choriogonadotropin alpha in human milk or effects on the breastfed infant.
• Caution: Confirm absence of pregnancy before administering; discontinue if pregnancy occurs during treatment cycle.

• Primary Class: Gonadotropin Hormone
• Subclass: Recombinant Human Chorionic Gonadotropin (rhCG)

• Hypersensitivity to choriogonadotropin alpha or any component of the formulation
• Known or suspected pregnancy
• Ovarian enlargement or ovarian cyst not due to polycystic ovary syndrome
• Primary ovarian failure (non-responsive ovaries)
• Uncontrolled thyroid or adrenal dysfunction
• Hormone-sensitive tumors (e.g., breast, ovarian, uterine cancer)
• Pituitary or hypothalamic tumors
• Uterine bleeding of unknown etiology

• Ovarian Hyperstimulation Syndrome (OHSS): Can be life-threatening; monitor patients for early signs (abdominal pain, weight gain, ascites, dyspnea).
• Multiple Gestations: Increased risk of twins or higher-order pregnancies.
• Thromboembolic Events: Higher risk in patients with OHSS or those predisposed to thrombosis.
• Ectopic Pregnancy: Especially in patients with tubal abnormalities; confirm intrauterine pregnancy via ultrasound.
• Ovarian Cyst or Torsion: May occur due to enlarged ovaries; avoid strenuous activity post-treatment.
• HCG Cross-Reactivity: Can interfere with pregnancy tests and serum hormone assessments for days after administration.
• Monitor Serum Estradiol and Ovarian Response regularly during stimulation cycles.

Common (≥1%):

• Injection site reactions: redness, swelling, pain
• Abdominal discomfort or bloating
• Nausea
• Headache
• Fatigue
• Breast tenderness

Serious:

• Ovarian Hyperstimulation Syndrome (OHSS)
• Mild: abdominal distension, nausea
• Severe: ascites, pleural effusion, oliguria, thromboembolism, respiratory distress
• Thromboembolism
• Ovarian torsion
• Multiple pregnancies (twins or more)
• Hypersensitivity reactions (rare)

Timing: Most side effects occur within a few days post-injection; OHSS may present later in the luteal phase or early pregnancy.

• No known major drug interactions. However, use cautiously with:
• Other fertility agents (FSH, LH, clomiphene): Increases risk of OHSS.
• Pregnancy tests: May cause false-positive for several days after injection.
• No CYP450 involvement. No data suggest enzyme induction or inhibition.

Drug-Food and Drug-Alcohol Interactions:

• None reported; avoid alcohol during fertility treatment for optimal outcomes.

• 2023 ASRM and ESHRE Fertility Guidelines: Continue to recommend choriogonadotropin alpha for final oocyte maturation in ART cycles; equivalent efficacy and safety compared to urinary hCG.
• 2024 FDA Safety Advisory: Emphasized patient education on signs of OHSS and appropriate timing of intercourse or oocyte retrieval post-injection.
• EMA (2023): Reaffirmed the benefit-risk balance of recombinant hCG over urinary preparations due to better purity and lower immunogenic potential.

• Unreconstituted Powder or Prefilled Syringe:
• Store at 2°C to 8°C (refrigerated) or at room temperature up to 25°C (check manufacturer’s specific instructions).
• Protect from light and moisture.
• Reconstituted Solution (if applicable):
• Use immediately after preparation.
• Discard any unused solution.
• Handling:
• Do not freeze.
• Visually inspect for particulate matter or discoloration before administration.
• Administer subcutaneously only with sterile technique.