Estrogens
Indications
Estrogens is used for:
Breast cancer, Prostate cancer, Hormone replacement therapy, Oral contraceptives
Adult Dose
Menopausal Vasomotor Symptoms, Atrophic Vaginitis/Kraurosis Vulvae
0.3 mg PO once daily in either continuous daily regimen or cyclic regimen (25 days on, 5 days off); adjusted PRN; use lowest dose that control symptoms; may be given daily if medical assessment warrants it
Female Hypogonadism
0.3-0.625 mg PO once daily in cyclic regimen (3 weeks on, 1 week off); may be titrated every 6-12 months; adjusted PRN; add progestin treatment should be added to maintain bone mineral density once skeletal maturity achieved
Osteoporosis
Prophylaxis
0.3 mg PO once daily in cyclic regimen (25 days on, 5 days off); adjusted PRN based on clinical response; may be given daily if medical assessment warrants it; administer lowest effective dose
May also be used in combination with medroxyprogesterone acetate
Prostate Cancer
Palliation only
1.25-2.5 mg PO q8hr
Abnormal Uterine Bleeding
10-20 mg/day PO divided q4hr
May administer low dose medroxyprogesterone acetate with therapy or following therapy
Cyclic therapy: 25 days on, 5 days off; either 3 weeks on, 1 week off
Female Castration/Primary Ovarian Failure
1.25 mg PO once daily in cyclic regimen (25 days on, 5 days off); adjusted PRN; administer lowest effective dose
Breast Cancer Palliation
Metastatic disease in selected patients (males and females):10 mg PO q8hr for ?3 months
Child Dose
Renal Dose
Administration
Contra Indications
Severe liver impairment; breast carcinoma; thromboembolic disorders; CV disease; undiagnosed vag bleeding; estrogen-dependent neoplasms; hypersensitivity; pregnancy.
Precautions
Asthma, epilepsy, migraine; heart or kidney dysfunction; CV disease; cerebrovascular disorders; diabetes, hypercalcaemia; gall bladder disease; porphyria. Childn. Lactation.
Lactation: Use controversial; estrogens are excreted into breast milk in small quantities; use with caution
Pregnancy-Lactation
Pregnancy Category: X
Lactation: Controversial; estrogens are excreted into breast milk in small quantities, use caution
Interactions
Rifampicin, barbiturates increase rate of metabolism.
Potentially Fatal: May reduce the efficacy of anticoagulants.
Adverse Effects
Side effects of Estrogens :
>10%
Abdominal pain (15-17%), Back pain (13-14%), Breast enlargement, Breast tenderness (7-12%), Headache (26-32%), Arthralgia (7-14%), Pharyngitis (10-12%), Sinusitis (6-11%), Diarrhea (6-7%)
1-10%
Depression (5-8%), Dizziness (4-6%), Nervousness (2-5%), Flatulence (6-7%), Vaginitis (5-7%), Leukorrhea (4-7%), Leg cramps (3-7%), Increased cough (4-7%), Pruritus (4-5%)
Frequency Not Defined
Amenorrhea, Breakthrough bleeding, Corneal curvation change, Melasma, Spotting, Vaginal moniliasis, Weight changes
Potentially Fatal: Unopposed replacement therapy in postmenopausal women associated with increased risk of endometrial and breast cancer.
Mechanism of Action
Estrogens modulate pituitary secretion of gonadotropins, leutinising hormones and follicle-stimulating hormones through -ve feedback mechanism, thus reducing elevated levels of hormones in postmenopausal women during oestrogen replacement therapy.