Considerations in the choice of oral vs. transdermal hormone therapy: a review.

The benefit/risk profile of postmenopausal hormone therapy has been under greater scrutiny since Women's Health Initiative study data were published in July 2002. A nominal analysis showed the study drug, a combination of 0.625 mg conjugated equine estrogens (CEE) and 2.5 mg medroxyprogesterone acetate (MPA), to be associated with decreased risks of colorectal cancer and osteoporotic hip fractures but increased risks of coronary heart disease, stroke and venous thromboembolic events. This same profile was not seen in the estrogen-only arm of the study, and the trial investigators cautioned that the results observed with CEE/MPA might not apply to other dosages of combined hormone therapy, other types of estrogens and progestins, or other routes of administration. However, the unexpected results cast a long shadow of doubt over the safety of all hormone therapy, making it difficult for reproductive health care professionals to counsel women on the selection of appropriate treatment of vasomotor symptoms. A review of the literature suggests that not all estrogens and progestins are alike, and alternative drugs, doses and delivery systems may exhibit better safety profiles than CEE/MPA, with no loss of efficacy. Selection of therapy should be individualized, based on patients' specific needs and global health risks. When there is a compelling need for relief of climacteric symptoms, using the lowest effective dose of hormonal therapy remains a prudent recommendation.