1. Clinical Overview
Human chorionic gonadotropin (hCG) is a glycoprotein hormone structurally and functionally similar to luteinizing hormone (LH). It is produced by the syncytiotrophoblast cells of the placenta during pregnancy. Therapeutically, it is derived from the urine of pregnant women or produced via recombinant DNA technology. In the Indian market, urinary-derived hCG is more common and cost-effective. The 10,000 IU strength is a high-dose formulation used for specific induction protocols in fertility treatment and for stimulating testosterone production in hypogonadism.
| Onset | Duration | Bioavailability |
|---|---|---|
| Following intramuscular (IM) injection, onset of action is typically within 6-12 hours, with peak steroidogenic effects (testosterone rise) occurring within 24-72 hours. | The biological effect persists for approximately 5-7 days post-injection, necessitating dosing regimens of 1-3 times per week. | Approximately 40-50% following intramuscular administration. Subcutaneous administration has comparable bioavailability. |
2. Mechanism of Action
hCG acts as an agonist at the luteinizing hormone (LH) receptor due to its structural homology with LH. In females, it mimics the mid-cycle LH surge, triggering the resumption of meiosis in the oocyte, rupture of the ovarian follicle (ovulation), and transformation of the residual follicle into the progesterone-secreting corpus luteum. In males, it stimulates Leydig cells in the testes to synthesize and secrete testosterone.
3. Indications & Uses
- Induction of ovulation and pregnancy in anovulatory infertility (e.g., PCOS) where the cause is functional and not due to primary ovarian failure.
- Preparation of oocytes for retrieval in Assisted Reproductive Technology (ART) like IVF/ICSI cycles.
- Treatment of hypogonadotropic hypogonadism (male hypogonadism) to stimulate spermatogenesis and testosterone production.
4. Dosage & Administration
Adult Dosage: **Female (Ovulation Induction):** 5,000-10,000 IU as a single IM/SC dose after adequate follicular development. **Female (ART):** 5,000-10,000 IU or 250 mcg recombinant hCG as a single dose. **Male (Hypogonadism):** 1,000-4,000 IU IM 2-3 times per week. Dosage adjusted based on testosterone response.
Administration: For intramuscular (IM) or subcutaneous (SC) injection only. Reconstitute the lyophilized powder with the provided sterile water for injection. Gently swirl to dissolve; do not shake vigorously. Inject into a large muscle (gluteus, thigh) for IM or into abdominal fat for SC. Rotate injection sites. Administer at the precise time instructed in fertility cycles (often at night for a morning retrieval).
5. Side Effects
Common side effects may include:
- Headache
- Irritability, restlessness
- Fatigue
- Injection site pain, redness, or swelling
- Mild fluid retention/edema
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Gonadotropins (Menotropins, FSH preparations) | Additive/synergistic effect; increases risk of ovarian hyperstimulation and multiple ovulation. | Major |
| Danazol, GnRH agonists (Leuprolide) | May interfere with the therapeutic response to hCG. | Moderate |
| Testosterone, Anabolic Steroids | Concurrent use in males may suppress endogenous LH/FSH; hCG is often used to counteract this suppression. | Moderate (Therapeutic interaction) |
| Corticosteroids | May enhance the androgenic effects of hCG in males. | Minor |
7. Patient Counselling
- **DO** administer the injection at the exact time instructed by your fertility specialist.
- **DO** rotate injection sites to prevent tissue hardening.
- **DO** store the unmixed vials in the refrigerator (2-8°C). Protect from light.
- **DO NOT** shake the vial vigorously after reconstitution; swirl gently.
- **DO NOT** use the medication if the solution is discolored or contains particles.
- **DO NOT** attempt to adjust the dose without consulting your doctor.
8. Toxicology & Storage
Overdose: Symptoms are an extension of pharmacological effects: severe OHSS in females (with massive ovarian enlargement, ascites, hydrothorax, hemoconcentration, thromboembolism). In males: excessive androgen effects (aggression, severe acne, polycythemia, excessive gynecomastia). Fluid retention can lead to hypertension and edema.
Storage: Store unopened vials (lyophilized powder and diluent) in a refrigerator between 2°C and 8°C. Do not freeze. Protect from light. After reconstitution, use immediately. If not used immediately, it may be stored refrigerated for up to 24 hours. Discard any unused solution. Keep out of reach of children.