Shot makes its mark in contraceptive options
When it comes to choosing an effective contraceptive, many women look to the contraceptive injection depot medroxyprogesterone acetate (DMPA, Depo-Provera Pfizer; New York City, Medroxyprogesterone Acetate Injection, Teva Pharmaceuticals USA; North Wales, PA), say respondents to the 2008 Contraceptive Technology Update Contraception Survey. The shot remains a popular option for younger women. About 91% of survey respondents say they would prescribe the injectable for young teens, up from 2007's 87% statistic.
In November 2004, the Food and Drug Administration added a "black box" warning to the drug's labeling to highlight that prolonged use may result in loss of bone mineral density (BMD). The warning advised that bone loss in women who use Depo-Provera is greater with increased duration of use and might not be completely reversible. The injectable contraceptive should be used as a long-term birth control method (longer than two years) only if other birth control methods are inadequate, the updated label advised.
The "black box" warning has made its impact on providers: According to results of a survey of Florida physicians, 46% of those surveyed said they place a time limit on DMPA use, and 66% stated that the limit was based on the label warning.1 Sixty-five percent of respondents ordered BMD testing solely due to the use of DMPA, with 58% indicating that this decision was based on the black box warning.
Concerns about the effects of the contraceptive injection on BMD should not prevent clinicians from prescribing the method, nor should its use be limited to two years, according to a committee opinion released in 2008 by the American College of Obstetricians and Gynecologists (ACOG).2
The ACOG opinion falls in line with a similar review issued by the World Health Organization (WHO) in 2005.3
As with pregnancy and lactation, use of DMPA is associated with loss of bone mass in current users, says Andrew Kaunitz, MD, professor and associate chair in the Obstetrics and Gynecology Department at the University of Florida College of Medicine — Jacksonville. "Fortunately, declines in bone mass with DMPA use, as with pregnancy and lactation, are reversible," he notes. "Of interest, bone mass recovers more rapidly when teens discontinue DMPA, or wean their baby, than with adult women."
About 57% of survey respondents say they only inform patients that DMPA may diminish bone mass. About 30% use other methods, such as counseling on calcium supplementation and weight-bearing exercise, to encourage bone health.
What is your facility's protocol for late DMPA re-injections? A woman may return after 13 weeks plus a four-week grace period (17 weeks from her last injection), indicate findings from a 2008 study.4
New guidance issued by WHO states: "A woman may have an injection of the progestin-only depot-medroxyprogesterone acetate (DMPA) up to four weeks late (17 weeks after the last injection). There is no need for other indications that she is not pregnant. Her next appointment still should be planned for three months. (Previous guidance said that she could have her DMPA reinjection up to two weeks late.)"5 The WHO still recommends that women be rescheduled for injections at 13 weeks. It does not recommend that women routinely return at 17 weeks.
References
- Paschall S, Kaunitz AM. Depo-Provera and skeletal health: A survey of Florida obstetrics and gynecologist physicians. Contraception 2008; 78:370-376.
- ACOG Committee Opinion No. 415: Depot medroxyprogesterone acetate and bone effects. Obstet Gynecol 2008; 112:727-730.
- World Health Organization. Technical Consultation on the Effects of Hormonal Contraception on Bone Health. Geneva; 2005. Accessed at www.who.int/reproductive-health.
- Steiner MJ, Kwok C, Stanback J, et al. Injectable contraception: What should the longest interval be for reinjections? Contraception 2008; 77:410-444.
- World Health Organization Department of Reproductive Health and Research (WHO/RHR) and Johns Hopkins Bloomberg School of Public Health/Center for Communication Programs (CCP), INFO Project. Family Planning: A Global Handbook for Providers (2008 update). Baltimore and Geneva: CCP and WHO; 2008.
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