Usage
Human chorionic gonadotropin (HCG) is a hormone produced by the placenta during pregnancy. It is used medically for treating infertility in both men and women and some specific medical conditions.
- In women, HCG is used to induce ovulation and treat infertility in women who do not ovulate on their own. This helps women with anovulatory infertility or as part of assisted reproductive technology (ART) procedures like in-vitro fertilization (IVF).
- In men, it is used to treat hypogonadism (a condition where the testes do not produce enough testosterone), cryptorchidism (undescended testicles) in young boys, and delayed puberty. It can also help stimulate testosterone production for male infertility.
Pharmacological Classification: Gonadotropin
Mechanism of Action: HCG mimics the luteinizing hormone (LH) and stimulates the production of testosterone in males and progesterone in females. In women, it triggers the final maturation of the ovarian follicle and release of an egg. In men, it stimulates the Leydig cells in the testes to produce testosterone, leading to the development of secondary sexual characteristics.
Alternate Names
Human Chorionic Gonadotrophin, HCG, uHCG (urinary HCG), rhCG (recombinant HCG)
How It Works
Pharmacodynamics: HCG binds to the LH/CG receptor on the Leydig cells in the testes and theca cells in the ovaries. This binding triggers a cascade of intracellular signaling, leading to increased steroidogenesis (production of testosterone in males and progesterone in females). In women, it triggers ovulation, while in men, it promotes testosterone production, which is essential for spermatogenesis and development of secondary sexual characteristics.
Pharmacokinetics: HCG is administered intramuscularly (IM) or subcutaneously (SC). After injection, it is absorbed into the bloodstream. It is metabolized in the liver and kidneys and excreted primarily in the urine.
Receptor Binding/Enzyme Inhibition/Neurotransmitter Modulation: HCG binds to LH/CG receptors, mimicking the effects of LH. It does not directly inhibit enzymes or modulate neurotransmitters.
Elimination Pathways: HCG is eliminated primarily through renal excretion (urine).
Dosage
HCG dosing depends on the patient’s age, condition being treated, and response to the medication. It should be individualized based on patient-specific factors and monitored closely by a healthcare professional.
Standard Dosage
Adults:
- Female:
- Ovulation Induction: 5,000 to 10,000 IU IM, single dose, following the last dose of menotropins or FSH.
- Male:
- Hypogonadism: 500-1000 IU IM 3x/week for 3 weeks, followed by 500-1000 IU IM 2x/week for 3 weeks
- Hypogonadotropic Hypogonadism: 4000 IU 3x/week for 6-9 months, then 2000 IU IM 3x/week for 3 months.
Children:
- Cryptorchidism:
- Various regimens exist. (See clinical use cases)
- Dosages vary depending on age and treatment response.
Special Cases:
- Elderly Patients: Clinical experience is limited, but dosage adjustments may be necessary based on renal function and other comorbidities.
- Patients with Renal Impairment: Caution is advised. Dosage adjustment based on creatinine clearance may be necessary.
- Patients with Hepatic Dysfunction: Dosage adjustments may be necessary.
- Patients with Comorbid Conditions: Consider underlying medical conditions and potential drug interactions.
Clinical Use Cases
HCG is generally not used in clinical settings like intubation, surgical procedures, mechanical ventilation, intensive care unit (ICU), or emergency situations. Its primary uses are for infertility and hypogonadism. However, for cryptorchidism, the following pediatric regimens are used:
- Cryptorchidism (age 4 and older): 4000 IU IM three times a week for 3 weeks OR 5000 IU IM every other day for 4 injections OR 500 to 1000 units IM for 15 injections over 6 weeks OR 500 units IM 3 times a week for 4-6 weeks. If unsuccessful, an additional series using 1000 units may be given starting 1 month later.
Dosage Adjustments
Dose modifications are required based on the patient’s renal function, liver function, concurrent medications, and response to treatment. Close monitoring of serum testosterone levels (in men), estradiol levels (in women), and other hormonal parameters is necessary to individualize therapy.
Side Effects
Common Side Effects:
- Headache
- Irritability
- Restlessness
- Fatigue
- Edema
- Depression
- Gynecomastia (in men)
- Pain or swelling at injection site
Rare but Serious Side Effects:
- Allergic reactions (hives, difficulty breathing, swelling)
- Ovarian Hyperstimulation Syndrome (OHSS) (in women) – can be life-threatening
- Blood clots
- Precocious puberty (in boys)
Long-Term Effects:
Long-term effects may include gynecomastia and increased risk of certain cancers.
Adverse Drug Reactions (ADR):
Serious ADRs include anaphylaxis, OHSS, and thromboembolic events. These require immediate medical attention.
Contraindications
- Hypersensitivity to HCG
- Precocious puberty
- Hormone-sensitive cancers (prostate, breast, ovarian, uterine)
- Undiagnosed vaginal bleeding
- Pituitary or hypothalamic tumors
- Uncontrolled thyroid or adrenal dysfunction
Drug Interactions
No severe or serious drug interactions have been noted with HCG. It can reduce the effectiveness of hormonal contraceptives so alternative methods should be used.
Pregnancy and Breastfeeding
-
Pregnancy: HCG is contraindicated during pregnancy beyond initial stages, as it’s no longer needed after placental development. Recombinant HCG should be avoided during pregnancy.
-
Breastfeeding: Caution advised. Limited data on excretion in breast milk. Use with caution if benefits outweigh potential risks to the infant.
Drug Profile Summary
- Mechanism of Action: Mimics LH, stimulating testosterone production in males and progesterone in females; triggers ovulation.
- Side Effects: Headache, irritability, edema, gynecomastia, OHSS, allergic reactions, blood clots.
- Contraindications: Hormone-sensitive cancers, precocious puberty, undiagnosed vaginal bleeding, pituitary/hypothalamic tumors.
- Drug Interactions: Can reduce effectiveness of hormonal contraceptives.
- Pregnancy & Breastfeeding: Contraindicated in established pregnancy; caution advised during breastfeeding.
- Dosage: Varies depending on indication and age, usually IM or SC. (Refer to dosage section.)
- Monitoring Parameters: Serum testosterone/estradiol levels, follicular development, pregnancy tests, signs of adverse effects.
Popular Combinations
HCG is often used in combination with other fertility medications, such as menotropins, FSH, and clomiphene.
Precautions
Screen for contraindications before starting HCG therapy. Monitor for side effects. Close monitoring required in children for precocious puberty and in women for OHSS.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Human chorionic gonadotropin?
A: HCG dosage varies depending on the indication and patient. (Refer to the dosage section for specific guidelines).
Q2: What are the primary uses of HCG in men?
A: Hypogonadism, cryptorchidism, delayed puberty, and male infertility.
Q3: How does HCG work in women experiencing infertility?
A: It triggers ovulation by mimicking LH.
Q4: What are the most serious side effects of HCG?
A: Allergic reactions, OHSS (in women), and blood clots.
Q5: Can HCG be used during pregnancy?
A: HCG is generally contraindicated in pregnancy beyond the initial stage, except for specific cases of luteal support in early pregnancy. Recombinant HCG should be avoided during pregnancy.
Q6: Is HCG safe during breastfeeding?
A: Limited information is available. Exercise caution. Consult a healthcare professional for personalized advice.
Q7: What are the contraindications for using HCG?
A: Hormone-sensitive cancers, precocious puberty, pituitary tumors, undiagnosed vaginal bleeding, uncontrolled thyroid or adrenal dysfunction.
Q8: How is HCG administered?
A: Intramuscularly (IM) or subcutaneously (SC).
Q9: How does HCG interact with other medications?
A: Limited clinically significant interactions have been noted, but it can reduce the effectiveness of hormonal birth control.
Q10: What are the common side effects of HCG for men?
A: Headache, irritability, restlessness, edema, gynecomastia, pain/swelling at the injection site.
Please note that this information is current as of February 16, 2025, and is intended for qualified medical professionals. Always refer to the latest medical guidelines and resources for the most up-to-date information.
