From the Guidelines
Vaginal estrogen options equivalent to 0.01% estradiol vaginal cream include estriol-containing preparations, such as pessaries containing estriol, which are as effective as those containing estradiol in treating symptomatic women 1. These low-dose local estrogen preparations are designed to treat vaginal atrophy symptoms with minimal systemic absorption. Some key points to consider when choosing a vaginal estrogen option include:
- The potency of the estrogen, with estradiol being more potent than estriol 1
- The potential for systemic effects, with vaginal estrogens having minimal impact on liver metabolism compared to systemic therapy 1
- The patient's individual needs and preferences, including cost considerations and ease of use
- The potential risks and benefits, including the potential for vaginal estrogens to interfere with the efficacy of aromatase inhibitors (AIs) in breast cancer patients 1 Other options, such as Vagifem (estradiol vaginal tablets 10 mcg), Estring (estradiol vaginal ring 2 mg, releasing approximately 7.5 mcg daily), may not be suitable for all patients, particularly those with a history of breast cancer or those taking AIs, due to the potential for increased circulating estradiol levels 1. In contrast, estriol-containing preparations may be a preferable option for these patients, as estriol is less potent than estradiol and cannot be converted to estradiol in the body 1. Ultimately, the choice of vaginal estrogen option should be based on the individual patient's needs and medical history, and should be made in consultation with a healthcare provider.
From the Research
Vaginal Oestrogen Options
Vaginal oestrogen options equivalent to 0.01% estradiol vaginal cream are available in various forms, including:
- Estradiol vaginal rings
- Estradiol vaginal tablets
- Estriol vaginal ovules or creams
Comparison of Vaginal Oestrogen Preparations
Studies have compared the safety and efficacy of different vaginal oestrogen preparations, including:
- A systematic review of 75 clinical trials found that newer low-dose estradiol rings, tablets, and inserts appear to induce the least increases in serum hormones, possibly indicating greater safety 2
- A study comparing the effects of continuous combined hormone replacement therapy with norethindrone acetate and low-dose ethinyl estradiol versus conjugated equine estrogens and medroxyprogesterone acetate found that the incidence and duration of vaginal bleeding were reduced with the low-dose ethinyl estradiol therapy 3
Safety of Vaginal Oestrogen Therapy
The safety of vaginal oestrogen therapy, particularly in breast cancer patients, has been investigated in several studies:
- A study found that vaginal estriol did not change serum estradiol or estriol levels in postmenopausal breast cancer patients receiving aromatase inhibitors, but significant decreases in levels of serum follicle stimulating hormone and luteinizing hormone were observed 4
- A review of the literature suggested that preliminary data indicate that much lower doses of vaginal estrogens can alleviate urogenital atrophy without influencing serum estrogenic levels, but further research is warranted to confirm whether vaginal estrogens are safe in symptomatic breast cancer patients 5