I don’t have a lot of women in my jails who take estrogen. The post-menopausal women I see usually are not prescribed replacement hormones by their outside doctors very often. The main reason for this is the momentum generated by the landmark study Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women’s Health Initiative randomized controlled trial published ten years ago in JAMA which said that the risks of hormone therapy following menopause outweighed the benefits. Most of the major women’s groups (here is one example) have backed off a little from this, saying now that for some women, post-menopausal hormones are OK, but should be done for as short of a time as possible.
Nevertheless, most of the women who are taking replacement estrogen are younger women who have had a total hysterectomy. Since these women are young, it is appropriate for them to take replacement estrogen. Since they do not have a uterus (for the most part), they do not need to take progestin. But which estrogen should be on our “Preferred Drug List” (otherwise known as a Formulary)?
In many drug categories, ACE inhibitors, say, there are several options that are equally effective and equally priced. I don’t care if a patient is taking lisinopril or enalopril. They are equivalent.
That is not the case with estrogens. It turns out that in the estrogen department, there is a clear winner.
Here is the price-per-pill breakdown. The doses listed are the typical standard doses for adult women.
Estrogen | Dose | Price Per Tablet |
Esterified Estrogen (Menest) | 0.625mg | $1.11 |
Estradiol (Estrace) | 1 mg | $0.04 |
Synthetic conjugated estrogens (Cenestin, Enjuvia) | 0.625mg | $3.27 |
Conjugated equine estrogen (Premarin) | 0.625mg | $3.09 |
Estropipate (Ogen) | 1.5mg | $0.24 |
Premarin has been around since 1942 and for many years, was the only available estrogen product, to the point that “Premarin” became almost synonymous for all estrogens in the same way that people say “Kleenex” for all nose-blowing tissues. Premarin continues to be the most prescribed replacement estrogen.
In fact, however, all of the estrogens are therapeutically equivalent. The only differences are these:
1. Premarin (conjugated equine estrogen or CEE) is derived from pregnant horse urine. That is the only thing (except price) that sets it apart from the others.
2. All the others, including synthetic conjugated estrogen, are made from plant proteins.
3. 17-beta-estradiol (usually just called estradiol, brand name Estrace) is the only formulation that is “bio-identical” to human estrogen.
So there you have it. By curious happenstance, the one estrogen that is bio-equivalent to human estrogen happens to be the one that costs 4 cents a tablet.
Estradiol should be the preferred estrogen in your facility.
Do you still use Premarin in your facility? Why or why not? Please comment!