Hormonal Oncology

Tamoxifen Citrate Tablets (10mg, 20mg) is a selective estrogen receptor modulator (SERM) on the WHO Model List of Essential Medicines. In breast tissue, it competitively antagonizes estrogen binding to estrogen receptors (ER), halting ER-mediated transcription and arresting breast tumor cells in the G0/G1 phase. In bone and cardiovascular tissues, it acts as an estrogen agonist (preserving bone density and lipid profiles), but in the endometrium, its partial agonism stimulates endometrial proliferation. Indicated for adjuvant and metastatic treatment of estrogen receptor-positive (ER+) breast cancer in premenopausal and postmenopausal women, ductal carcinoma in situ (DCIS), and breast cancer chemoprevention in high-risk women.

Tamoxifen Citrate Tablets (10mg, 20mg) is a selective estrogen receptor modulator (SERM) on the WHO Model List of Essential Medicines. In breast tissue, it competitively antagonizes estrogen binding to estrogen receptors (ER), halting ER-mediated transcription and arresting breast tumor cells in the G0/G1 phase. In bone and cardiovascular tissues, it acts as an estrogen agonist (preserving bone density and lipid profiles), but in the endometrium, its partial agonism stimulates endometrial proliferation. Indicated for adjuvant and metastatic treatment of estrogen receptor-positive (ER+) breast cancer in premenopausal and postmenopausal women, ductal carcinoma in situ (DCIS), and breast cancer chemoprevention in high-risk women.

Megestrol Acetate Tablets (40mg) is a synthetic oral derivative of progesterone on the PMBI formulary. It downregulates luteinizing hormone secretion, exerts antiestrogenic activity in hormone-sensitive tumors, and centrally stimulates neuropeptide Y (NPY) and downregulates catabolic cytokines (TNF-alpha, IL-1, IL-6) in the hypothalamus, powerfully stimulating appetite and promoting non-fluid body weight gain. Indicated for treatment of anorexia, cachexia, and unexplained significant weight loss in patients with advanced cancer or AIDS, and palliative treatment of advanced endometrial and recurrent breast carcinoma.

Anastrozole Tablets (1mg) is a potent and selective non-steroidal third-generation aromatase inhibitor on the WHO Model List of Essential Medicines. It inhibits aromatase (CYP19A1) by competitive binding, suppressing serum estradiol concentrations by >80-85% in postmenopausal women without affecting cortisol, aldosterone, or thyroxine synthesis. Indicated for adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer and first-line treatment of locally advanced or metastatic HR+ breast cancer.

Bicalutamide Tablets (50mg) is an oral non-steroidal antiandrogen on the WHO Model List of Essential Medicines. It competitively antagonizes androgen binding to nuclear androgen receptors (AR) in the prostate gland and peripheral target tissues, preventing DHT-induced gene expression and cellular proliferation without displaying progestational or glucocorticoid agonist activity. Indicated in combination with a luteinizing hormone-releasing hormone (LHRH / GnRH) analogue for treatment of stage D2 metastatic prostate carcinoma (complete androgen blockade) and to prevent initial tumor flare upon LHRH agonist initiation.

Letrozole Tablets (2.5mg) is an oral non-steroidal third-generation aromatase inhibitor on the WHO Model List of Essential Medicines. It competitively binds to the heme group of the CYP19A1 aromatase enzyme, inhibiting the peripheral conversion of androgens (androstenedione and testosterone) to estrogens (estrone and estradiol) in adipose and peripheral tissues by >98.8%. In postmenopausal women, peripheral aromatization is the primary estrogen source. Indicated for adjuvant and first-line treatment of postmenopausal women with hormone receptor-positive (HR+) breast cancer, extended adjuvant therapy after 5 years of tamoxifen, and off-label ovulation induction in polycystic ovary syndrome (PCOS).

Leuprolide Acetate Depot Injection (3.75mg) is a synthetic nonapeptide gonadotropin-releasing hormone (GnRH / LHRH) superagonist on the WHO Model List of Essential Medicines. Following an initial transient surge in LH and FSH release (the "tumor flare" phenomenon lasting 1-2 weeks), continuous non-pulsatile administration profoundly downregulates pituitary GnRH receptors. Within 2 to 4 weeks, pituitary LH and FSH secretion is extinguished, suppressing testicular testosterone synthesis to surgical castration levels (<=50 ng/dL) in men and ovarian estradiol production to postmenopausal levels in women. Indicated for palliative treatment of advanced prostate cancer, central precocious puberty, endometriosis, and uterine leiomyomata (fibroids).

Abiraterone Acetate Tablets (250mg, 500mg) is an oral prodrug inhibitor of androgen biosynthesis on the WHO Model List of Essential Medicines. It is converted to abiraterone, which selectively and irreversibly inhibits the 17-alpha-hydroxylase and C17,20-lyase activities of the CYP17A1 enzyme in testicular, adrenal, and intratumoral prostate cancer tissues. This shuts down androgen synthesis across all three sources, depriving androgen-dependent prostate cancer cells of testosterone and DHT. Because CYP17 inhibition blocks cortisol production, secondary ACTH elevation triggers mineralocorticoid excess (hypertension, hypokalemia, edema); therefore, abiraterone MUST ALWAYS be co-administered with oral prednisone. Indicated in combination with prednisone for metastatic castration-resistant prostate cancer (mCRPC) and metastatic high-risk castration-sensitive prostate cancer (mCSPC).

Octreotide Injection (50mcg, 100mcg immediate-release; 20mg, 30mg Long-Acting Release LAR depot) is a synthetic octapeptide analogue of natural somatostatin on the WHO Model List of Essential Medicines. It binds with high affinity to somatostatin receptor subtypes sst2 and sst5, potently inhibiting the pathological hypersecretion of growth hormone (GH), insulin-like growth factor-1 (IGF-1), serotonin, gastrin, VIP, and glucagon, and causing splanchnic vasoconstriction. Indicated for symptomatic control of carcinoid syndrome (flushing, severe diarrhea), VIPomas, acromegaly, emergency management of bleeding gastroesophageal varices, and prevention of postoperative pancreatic fistula.

Octreotide Injection (50mcg, 100mcg immediate-release; 20mg, 30mg Long-Acting Release LAR depot) is a synthetic octapeptide analogue of natural somatostatin on the WHO Model List of Essential Medicines. It binds with high affinity to somatostatin receptor subtypes sst2 and sst5, potently inhibiting the pathological hypersecretion of growth hormone (GH), insulin-like growth factor-1 (IGF-1), serotonin, gastrin, VIP, and glucagon, and causing splanchnic vasoconstriction. Indicated for symptomatic control of carcinoid syndrome (flushing, severe diarrhea), VIPomas, acromegaly, emergency management of bleeding gastroesophageal varices, and prevention of postoperative pancreatic fistula.

Octreotide Injection (50mcg, 100mcg immediate-release; 20mg, 30mg Long-Acting Release LAR depot) is a synthetic octapeptide analogue of natural somatostatin on the WHO Model List of Essential Medicines. It binds with high affinity to somatostatin receptor subtypes sst2 and sst5, potently inhibiting the pathological hypersecretion of growth hormone (GH), insulin-like growth factor-1 (IGF-1), serotonin, gastrin, VIP, and glucagon, and causing splanchnic vasoconstriction. Indicated for symptomatic control of carcinoid syndrome (flushing, severe diarrhea), VIPomas, acromegaly, emergency management of bleeding gastroesophageal varices, and prevention of postoperative pancreatic fistula.

Octreotide Injection (50mcg, 100mcg immediate-release; 20mg, 30mg Long-Acting Release LAR depot) is a synthetic octapeptide analogue of natural somatostatin on the WHO Model List of Essential Medicines. It binds with high affinity to somatostatin receptor subtypes sst2 and sst5, potently inhibiting the pathological hypersecretion of growth hormone (GH), insulin-like growth factor-1 (IGF-1), serotonin, gastrin, VIP, and glucagon, and causing splanchnic vasoconstriction. Indicated for symptomatic control of carcinoid syndrome (flushing, severe diarrhea), VIPomas, acromegaly, emergency management of bleeding gastroesophageal varices, and prevention of postoperative pancreatic fistula.

Abiraterone Acetate Tablets (250mg, 500mg) is an oral prodrug inhibitor of androgen biosynthesis on the WHO Model List of Essential Medicines. It is converted to abiraterone, which selectively and irreversibly inhibits the 17-alpha-hydroxylase and C17,20-lyase activities of the CYP17A1 enzyme in testicular, adrenal, and intratumoral prostate cancer tissues. This shuts down androgen synthesis across all three sources, depriving androgen-dependent prostate cancer cells of testosterone and DHT. Because CYP17 inhibition blocks cortisol production, secondary ACTH elevation triggers mineralocorticoid excess (hypertension, hypokalemia, edema); therefore, abiraterone MUST ALWAYS be co-administered with oral prednisone. Indicated in combination with prednisone for metastatic castration-resistant prostate cancer (mCRPC) and metastatic high-risk castration-sensitive prostate cancer (mCSPC).

Enzalutamide Tablets (40mg) is a second-generation non-steroidal androgen receptor inhibitor on the WHO Model List of Essential Medicines. It exerts a triple mechanism: competitive inhibition of androgen binding to androgen receptors (with 8-fold higher affinity than bicalutamide), inhibition of androgen receptor nuclear translocation, and inhibition of androgen receptor DNA binding and coactivator recruitment, inducing prostate cancer cell apoptosis without agonistic properties. Indicated for castration-resistant prostate cancer (metastatic and non-metastatic CRPC) and metastatic castration-sensitive prostate cancer (mCSPC).