Estrogen Replacement Therapy in Menopause
Hormone replacement therapy (HRT) should primarily be used for management of menopausal symptoms rather than for prevention of chronic conditions, using the lowest effective dose for the shortest possible time. 1
Indications and Approach to HRT
- HRT is most effective for treating vasomotor symptoms (hot flashes) and genitourinary symptoms, reducing vasomotor symptoms by approximately 75% 1, 2
- Consider initiating HRT at the onset of menopausal symptoms, typically around the median age of 51 years (range 41-59 years) 1, 3
- The benefit-risk profile is most favorable for women under 60 years of age or within 10 years of menopause onset 1
- For short-term symptom management (4-5 years), HRT is reasonable for recently menopausal women with moderate to severe symptoms who are in good cardiovascular health 4
Hormone Selection and Regimen
- For women without a uterus, estrogen-alone therapy can be used 1, 3
- For women with an intact uterus, combination estrogen and progestin therapy is required to prevent endometrial cancer, reducing the risk by approximately 90% 1, 3
- 17-β estradiol is the preferred estrogen for replacement therapy over ethinylestradiol or conjugated equine estrogens 3
- Transdermal routes of administration are preferred as they have less impact on coagulation factors and may be safer for cardiovascular health 1, 3, 5
- Low-dose vaginal estrogens are highly effective for genitourinary atrophy symptoms with minimal systemic absorption 4
Risk-Benefit Assessment
- Based on WHI data, for every 10,000 women taking estrogen and progestin for 1 year, there might be 7 additional CHD events, 8 more strokes, 8 more pulmonary emboli, and 8 more invasive breast cancers, balanced against 6 fewer cases of colorectal cancer and 5 fewer hip fractures 1, 6
- Estrogen therapy increases bone density and reduces risk for fractures by approximately 30-50% 3
- Risks appear to increase with longer-term HRT use, particularly beyond 5 years 3, 4
- Initiation of estrogen many years after menopause is associated with excess coronary risk, whereas initiation soon after menopause may not carry the same risk 4
Absolute Contraindications
- History of breast cancer 1, 7
- Coronary heart disease 1
- Previous venous thromboembolic event or stroke 1
- Active liver disease 1
- Antiphospholipid syndrome 1
- Hormone-sensitive cancers 1, 7
Duration of Therapy
- Expert groups recommend using the lowest effective dose for the shortest possible time 1, 4
- Short-term therapy is considered to be not more than 4-5 years because symptoms typically diminish after several years, whereas the risk of breast cancer increases with longer duration of HRT 4
- For women with persistent severe symptoms after stopping HRT, consider nonhormonal alternatives such as gabapentin, selective serotonin reuptake inhibitors, or serotonin norepinephrine reuptake inhibitors before returning to estrogen 4
Monitoring
- Annual clinical review is recommended, with particular attention to compliance 3
- Assess symptom control and side effects at follow-up visits 3
- Consider bone density testing if osteoporosis is a concern 3
Common Pitfalls to Avoid
- Initiating HRT solely for prevention of chronic conditions like osteoporosis or cardiovascular disease 8, 1
- Failing to distinguish between different HRT regimens and routes of administration, which can have varying risk profiles 1
- Using HRT routinely for the specific purpose of preventing chronic disease without considering individual risk-benefit profile 8, 3
- Continuing HRT beyond 5 years without reassessing the risk-benefit ratio 4