Подпись:Depo-medroxyprogesterone acetate (DMPA, or Depo-Provera; DEP-poe PRO-vair – uh) was approved for use in the United States in 1992 and today is the most popular form of nonoral contraceptive (Hatcher et al., 2004). Depo-Provera is injected into the muscle of a woman’s arm or buttock once every 3 months, and each injection costs $30 to $125. Depo-Provera begins working within 24 hours after the injection, and fertility resumes approximately 10 months after the last injection (Hatcher et al., 2004; Kaunitz et al., 1998).

In 2004, the FDA issued a “black box warning” that long-term use of Depo may re­sult in the loss of bone density (U. S. Food and Drug Administration, 2004). This was a concern for female adolescents because they develop most of their bone mass between the ages of 15 to 19 and losing bone density could put a woman at risk for bone fractures or osteoporosis later in life. However, newer research has found that bone loss is re­versible after a woman stops using Depo-Provera (Scholes et al., 2005).

Other injectable contraceptive devices have been available in several countries over the past few years. Noristerat, a long-acting drug, provides circulating levels of hormones to suppress ovulation and to make the endometrium inhospitable to the ovum.

How It Works Depo-Provera is an injectable form of contraception that contains synthetic progesterone, and it works chiefly by preventing ovulation and thickening cer­vical mucus. Supporters of Depo-Provera cite the fact that it does not contain estrogen (like some birth control pills), so it can be used by lactating and postpartum women or those who have adverse reactions to estrogen.

Effectiveness Similar to oral contraceptives, Depo-Provera has a 97% (typical use) to 99.7% (perfect use) effectiveness rate (Hatcher, 2004).

Advantages Depo-Provera is a highly effective method of birth control, and one injection lasts for 3 months. It is only moderately expensive, reversible, does not con­tain estrogen, and does not restrict spontaneity. Users of Depo-Provera often notice de­creased cramping and pain during menstruation, and lighter periods. In fact, 30% to 50% of users have no menstrual periods at all (Hatcher, 2004). Depo use also reduces the risk of endometrial and ovarian cancer (Hatcher, 2004).

Disadvantages Women who use Depo-Provera must schedule office visits every 3 months for their injections, and they often experience irregular bleeding and spotting. Other potential side effects include fatigue, dizzy spells, weakness, headaches, appetite in­crease (it is estimated that a woman will gain an average of 5.4 pounds in the first year of Depo use), and a decrease in bone density (Hatcher, 2004). Use may increase risk of cer­vical, liver, and/or breast cancers, and Depo-Provera cannot be used by women with a his­tory of liver disease, breast cancer, or unexplained vaginal bleeding or blood clots. A re­turn to fertility may take approximately 10 months after discontinuing the injections.

Подпись: ReviewQuestion Differentiate between the estrogen- based and progestin-only hormonal methods of birth control, providing information on how the methods work, effectiveness rates, advantages and disadvantages, and cross-cultural use. Подпись:Подпись:Cross-Cultural Use Depo-Provera has been approved for use in more than 80 countries, including Botswana, Denmark, Finland, Great Britain, France, Sweden, Mexico, Norway, Germany, New Zealand, South Africa, and Belgium (Hatcher et al., 2004; Francoeur & Noonan, 2004). It has not been approved for contraceptive use in Australia, although it has been used for many years for other medical treatments (Coates, 2004). It has not been widely used in a variety of countries, including Brazil, Canada, China, Columbia, Croatia, Cuba, Czech Republic, Ireland, Japan, Kenya, and Spain (Francoeur & Noonan, 2004). Low usage rates may be due to a lack of marketing or religious prohibition.