Key points in androgens and antiandrogens:
- Testosterone and dihydrotestosterone (DHT) are the most important androgens. Other less potent androgens include androstenedione and Dehydroepiandrosterone (DHEA).
- Androgens are used for various purposes, such as compensating for decreased endogenous secretion in hypogonadal men, reducing breast engorgement during the postpartum period, stimulating growth in boys with delayed puberty, and treating osteoporosis. They are also frequently abused by athletes due to their anabolic properties.
- Adverse effects of androgens include masculinizing actions in females, increased risk of atherosclerosis, under-masculinization of the male fetus, sodium retention and edema, cholestatic jaundice, erythrocytosis, gynecomastia, and azoospermia. Androgens are contraindicated in pregnant females, infants, carcinoma of the male breast and prostate, and patients with cardiac and renal diseases.
- Danazol is a compound with weak androgenic, progestational, and glucocorticoid activities. It is used to treat endometriosis, fibrocystic disease of the breast, hemophilia, Christmas disease, ITP, and angioneurotic edema. Adverse effects of danazol include weight gain, edema, acne, increased hair growth, hot flushes, changes in libido, and mild to moderate hepatocellular damage.
- Anti-androgens can act by inhibiting the synthesis, activation, or action of androgens. Examples include steroid synthesis inhibitors (ketoconazole and abiraterone), 5-α reductase inhibitors (finasteride and dutasteride), and androgen receptor antagonists (cyproterone, cyproterone acetate, flutamide, bicalutamide, enzalutamide, nilutamide, and apalutamide). Spironolactone, an aldosterone antagonist, can also be used for the treatment of hirsutism.
GnRH Agonist and Antagonists
- Gonadotropins and gonadotropin-releasing hormone (GnRH) are hormones involved in reproductive functions.
- The anterior lobe of the pituitary gland secretes gonadotropins, including Follicle stimulating hormone (FSH) and luteinising hormone (LH).
- FSH is involved in spermatogenesis and estrogen secretion, while LH stimulates progesterone and testosterone secretion.
- The mid-cycle LH surge triggers ovulation.
- GnRH, secreted by the hypothalamus, controls the secretion of these hormones in a pulsatile manner.
- Deficiency or excess of gonadotropins can lead to various reproductive disorders.
- Synthetic GnRH (gonadorelin) is used to diagnose pituitary or hypothalamic defects in patients with hypogonadotropic hypogonadism.
- GnRH analogues are more potent and longer-acting than natural GnRH and can be used in a pulsatile or continuous manner to stimulate or inhibit gonadotropin secretion, depending on the medical condition being treated.
- GnRH antagonists like buserelin, goserelin, leuprolide, nafarelin, deslorelin, triptorelin, and histrelin are used to prevent premature spontaneous ovulation during controlled ovarian stimulation in in-vitro fertilization and for the treatment of uterine fibroids and endometriosis.
- GnRH agonists and antagonists can cause hot flushes, loss of libido, and osteoporosis as side effects.
Disclaimer: This article is for informational purposes only and should not be taken as medical advice. Always consult with a healthcare professional before making any decisions related to medication or treatment.