Depo-Provera

WASHINGTON -- The latest data on Depo-Provera and weight gain indicate that, at least in the short term, use of the injectable contraceptive is not associated with weight gain.

That finding emerged from a small, randomized, placebo-controlled 8-week trial that produced good quality data, unlike previously reported studies of weight gain in DEPO-PROVERA users, Dr. Andrew M. Kaunitz said during the annual meeting of the Association of Reproductive Health Professionals.

Dr. Kaunitz is a consultant to and has conducted clinical trials for Pharmacia Corp., manufacturer of Depo-Provera (medroxyprogesterone acetate).

In the state-of-the-art metabolic study of 20 student volunteers of normal weight, 10 received one injection of Depo-Provera and 10 received a placebo injection.

After 8 weeks, no weight gain, increase in appetite, or change in basal metabolic rate was seen in either group (Am. J. Clin. Nutr. 73[1]:19-26, 2001), said Dr. Kautnitz, who was not an investigator in the trial.

Larger long-term, randomized, controlled studies that focus on weight and enroll users and nonusers who are otherwise comparable are still needed to definitively address the question of whether the high-dose progestin-only contraceptive causes weight gain, said Dr. Kaunitz, who is professor and assistant chairman of obstetrics and gynecology at the University of Florida Health Science Center, Jacksonville.

Until these data are available, he advised sharing the results of this study and other available information with patients in addition to basic advice about exercise and good nutrition.

The other data on weight gain in Depo-Provera users are of poorer quality, he added.

The patient label for Depo-Provera, which says that women may gain weight in the first year of use, refers to clinical trials in which about two-thirds of women reported a 5-pound weight gain in the first year of use.

But this statement is based on uncontrolled studies published more than 25 years ago, he noted.

No weight gain was observed in women on Depo-Provera in several studies from the United States and Thailand and an uncontrolled Chinese study published in the 1990s.

But weight gain was observed in another study published in 2000 that was conducted in a Navajo community.

Nevertheless, these studies have been observational, so they may not distinguish between Depo-Provera's impact on weight gain and a woman's intrinsic risk of weight gain.

Other unresolved issues concerning Depo-Provera are the impact the contraceptive has on bone mineral density, mood disorders, and libido, Dr. Kaunitz added.

The available data indicate that bone mineral density is reduced in current users of Depo-Provera but that it recovers once use is discontinued.

More relevant is what happens to former users, he said, noting that there does not seem to be a deficit in bone mineral density in younger women of reproductive age who were recent users or in postmenopausal women who used the contraceptive earlier in their lives.

In a cross-sectional study of menopausal women in New Zealand, where Depo-Provera has been used for decades, bone mineral density of the spine and hip were identical in women who had used Depo-Provera earlier in their lives and those who had never used it.

Use of the contraceptive is also associated with drops in bone mineral density in adolescents, but there are no data on the long-term impact in former teen users.

In Dr. Kaunitz's view, the impact Depo-Provera has on bone mineral density may correlate with the effects of lactation: Lactation is also associated with reduced estradiol levels and a transient drop in bone mineral density, which rebounds after weaning but is not a risk factor for postmenopausal osteoporosis.

"In my practice bone density concerns do not prevent me from prescribing Depo to any patient who otherwise is an appropriate user and will benefit from this very effective method," including adolescents, Dr. Kaunitz said during the conference.

He recommends encouraging adequate calcium intake in users, as with all women, and said that clinicians who are concerned about the potential for osteopenia in women on long-term Depo-Provera who are at high risk for the disorder can consider using add-back estrogen.

Although some clinicians recommend against using Depo-Provera in women with depression, Dr. Kaunitz pointed out that it is not contraindicated in women who have preexisting clinical depression or mood disorders.

According to Depo-Provera labeling information, women with a history of mental depression should be carefully observed after being given the shot and if depression recurs, it should not be readministered.

Furthermore, while some women who use Depo-Provera may experience a negative impact on mood, he referred to two recent studies showing that overall clinical depression scores improved with use.

A reduced libido has been reported in women on Depo-Provera, but this does not appear to be a common problem, he said.

As with other hormonal methods of contraception, some women may experience an increased libido because they are no longer worried about the risk of an unintended pregnancy.

In two studies of more than 1,000 women on the contraceptive for 12 months, no reduction in libido was observed, he noted.

COPYRIGHT 2002 International Medical News Group
COPYRIGHT 2002 Gale Group