Depo-SubQ Provera 104 is a medication that is related to the hormone progesterone. It is a contraceptive medication; that is, it is used to prevent unwanted pregnancies. The Depo-SubQ prescribing information for physicians reports that it is injected subcutaneously, or under the skin, every 12 to 14 weeks; this injection suppresses the release of hormones required for ovulation. Without ovulation, pregnancy cannot occur. Depo-SubQ Provera is associated with several side effects that are important for patients to consider before starting this type of contraceptive.
Bone Density Decrease
One of the results of Depo-SubQ injection is a decrease the levels of estrogen in the woman's body. This, in turn, causes a decrease in the density of bones throughout the body. The concern with women taking Depo-SubQ is that perhaps their lower-than-normal bone mineral density would put them at risk for developing osteoporosis, in which the bone becomes more brittle than normal and is more prone to fractures. In a review of 39 studies, however, published in the journal "Contraception" in 2006, the authors conclude that while there is an association between losing bone density and taking Depo-SubQ, there does not seem to be a major impact on the risk of bone fractures. Despite this result, the U.S. Food and Drug Administration now requires a "black box warning" label on Depo-SubQ packages, warning patients of the side effect of bone mineral density loss and the potential risk for osteoporosis. Because of this, the prescribing information for Depo-SubQ indicates that patients who may have other risk factors for developing osteoporosis, such as a strong family history of the disease, may want to consider other forms of contraception.
Weight Gain
The medical reference UpToDate reports that the side effect of weight gain depends somewhat on the group of women that are taking the medication. For example, a 2010 study published in the journal "Contraception" found that adolescent women using medications such as Depo-SubQ gained more weight than adolescents who were using contraceptives such as an oral birth control pill or used no contraceptives. The average weight gain while using Depo-SubQ is 8 lbs. during the first two years.
Changes in the Menstrual Cycle
Another side effect that can be quite unpleasant for women is that their menstrual cycle may change. UpToDate reports that more than 5 percent of women using Depo-SubQ may experience such changes, which include spotting in between cycles, unpredictable bleeding that lasts over a week, or the complete opposite effect--no menstrual cycles at all. This latter may be especially startling, as women may wonder if they are pregnant. As reported in UpToDate, however, if the physician explains to the patient that she may stop having periods, the fear of pregnancy can be minimized; the woman may find that the lack of periods is actually a benefit of this kind of contraception.
References
- Pfizer: Depo-SubQ 104
- "Contraception:'; Progestogen-only contraception and bone mineral density: a systematic review; K.M. Curtis and S.L. Martins; May 2006
- "Contraception;" Prospective study of weight change in new adolescent users of DMPA, NET-EN, COCs, nonusers and discontinuers of hormonal contraception; M.E. Beksinska et. al.; January 2010
- "UpToDate"; Depot medroxyprogesterone acetate for contraception; Andrew Kaunitz; June 2010
- "UpToDate"; Medroxyprogesterone acetate: Drug information; Lexi-Comp, Inc.; 2010
