These women should have a baseline bone mineral density test to make sure that they do not have established osteoporosis. This new combination tablet is novel in that it contains a well-tolerated progestin, norgestimate. Norgestimate has been used in higher doses in OrthoTri-Cyclen, a commonly prescribed oral contraceptive pill. The sole reason for taking progestin with estrogen is to prevent endometrial cancer. Many of the commonly prescribed progestins often cause side effects such as bloating, breast tenderness, headache, mood disorder, and abnormal bleeding.
Some progestins can also reverse the benefits of estrogen on lipid and carbohydrate metabolism.
Norgestimate has been shown in several well-controlled studies to have very few side effects and has a favorable effect on lipid and carbohydrate metabolism. This regimen provides an overall lower dose of progestin throughout the month. The good news is that in well designed, placebo controlled trials, this pulsed regimen was effective in controlling uterine bleeding and provided endometrial protection. It was also shown to have a favorable lipid profile and very few side effects while effectively treating menopausal symptoms. This new regimen clearly has the benefit of reducing the monthly exposure to progestin while maximizing the benefits of estrogen therapy.