RESUMO
A comparative study was undertaken involving 21 Mexican women who discontinued the use of medroxyprogesterone acetate 25 mg plus oestradiol cypionate 5 mg (Cyclofem) and norethisterone enanthate 50 mg plus oestradiol valerate 5 mg (Mesigyna) to assess the time required for the return to menses and ovulation. All subjects were exposed to once-a-month injectable contraceptives for two years and were followed for 120 days after the last injection. The urinary concentration of oestrone glucuronide and pregnanediol glucuronide was determined daily in all subjects beginning one month after the last injection. The results disclosed that ovulatory cycles were documented after 120 days of the last injection in six women of each studied group. Similar endometrial bleeding patterns were observed in both groups, indicating that the two drugs have alike pharmacokinetic and pharmacodynamic effects.
PIP: At the family planning clinic of the medical school in Coahuila, Mexico, providers recruited 11 volunteers requesting an injectable contraceptive into Group I (Mesigyna: 50 mg norethisterone enanthate + 5 mg estradiol valerate) and 10 similar volunteers into Group II (Cyclofem: 25 mg medroxyprogesterone acetate + 25 mg estradiol cypionate). After they used the injectables continuously for two years, researchers followed them for 120 days after the last injection. Early morning urine samples were taken every day between day 30 and day 120 after the last injection to measure estrone glucuronide and pregnanediol glucuronide. Researchers also measured the urinary luteinizing hormone level. Normal ovulatory cycles returned within the first to third month after injection in six users from each group. In fact, all but one woman in the Group I had a normal ovulatory cycle during the first month. The other woman had a normal cycle during the second month. During months 1, 2, and 3, the numbers of women in group II who had a normal ovulatory cycle were 3, 2, and 1, respectively. The two groups did not have significant differences in the first bleeding-free interval (51 for Group I vs. 43 for Group II) and in the total number of bleeding/spotting days (11 vs. 14). These findings suggest that long-term use of these injectable contraceptives did not cause chronic inhibition of the hypothalamus-pituitary-ovarian axis and that the ovarian function and the endometrial bleeding patterns returned to normal similarly in both groups. Thus, national family planning programs in developing and developed countries may want to consider offering them as part of the contraceptive mix.