A comparative study of two low-dose combined oral contraceptives: results from a multicenter trial.

A comparative multicenter clinical trial of two low-dose combined oral contraceptives (OCs) was conducted in Malaysia, Egypt, Thailand, and Mexico. Efficacy, safety and acceptability were investigated in women taking either a norgestrel-based (NG) OC or a norethindrone acetate-based (NA) OC. This paper includes analysis of 892 women, all of whom were at least 42 days but within 26 weeks postpartum and randomly allocated to one of the above OCs. Follow-up visits were scheduled at 1, 4, 8 and 12 months after admission. Baseline sociodemographic characteristics were similar for both groups, as well as compliance. There were nine unintended pregnancies reported; eight of these occurring in the NA group. Adverse experiences were minor with headaches and dizziness being the most common complaints; frequency of reports was similar in both groups. The group taking the NG-based OC had significantly (p < .05) fewer menstrual-related complaints. Discontinuations due to menstrual problems were significantly more common among NA users (primarily amenorrhea). Discontinuations in the NG group were primarily for other personal reasons, e.g. unable to return to the clinic. There was also a significant difference between the two groups for the 11-month gross cumulative life table discontinuation rates due to menstrual problems (p < .01); the NA group had the higher rate.

A multicenter comparative trial of triphasic and monophasic, low-dose combined oral contraceptives.

A comparative multicenter clinical trial of two combined oral contraceptives (OCs) was conducted at clinics located in the Sudan, Sri Lanka, Chile, the Dominican Republic and Ecuador. The trial was designed to determine if there were differences in efficacy, safety and acceptability between a triphasic and a low-dose monophasic OC. This report includes analysis of 1088 women. At each center, subjects were randomly allocated to one of the two OCs. Follow-up visits were scheduled at 1, 4, 8 and 12 months after admission. There were two accidental pregnancies attributed to user failure reported during the study period; one in the triphasic group and one in the monophasic group. Adverse experiences were mainly minor with headaches and dizziness being the most common complaints; frequency of reports was similar in both groups. Cycle control was good in both groups with women in the triphasic group reporting fewer complaints of intermenstrual bleeding. Both OCs were safe and effective.

PIP: Researchers compared the efficacy, safety, and acceptability of a triphasic oral contraceptive (OC), Triquilar, with those of a monophasic OC, Lo-Femenal, among 1088 women attending clinics in Chile, the Dominican Republic, Ecuador, Sri Lanka, and the Sudan. Both OCs contained levonorgestrel and ethinyl estradiol. 90% of women in each group exhibited good user compliance. Only 1 unplanned pregnancy occurred in each group, and both pregnancies were attributed to user failure. The gross cumulative efficacy rates at 11 months were 0.3/100 woman-years for the triphasic OC and 0.2/100 woman-years for the monophasic OC. The continuation rate at 11 months was lower for Lo-Femenal than it was for Triquilar (80.8% vs. 84.6%), but the difference was not significant. The leading side-effect-related reason for discontinuation in both groups was headache. Another key reason for OC discontinuation in both groups was personal reasons, such as planning a pregnancy. Most women in both groups did not have menstrual complaints (78.8% for the Triquilar group and 77.1% for the Lo-Femenal group). Intermenstrual bleeding rates were low (7.6% for the Triquilar group and 9% for the Lo-Femenal group). Significant intercenter differences for women reporting intermenstrual bleeding and side effects (e.g., headaches) existed (p .05). Women from both groups at the clinic in the Sudan always had lower reports of intermenstrual bleeding than those at the other clinics. In fact, no woman discontinued OC use because of intermenstrual bleeding in the Sudan. Women in Sri Lanka reported fewer side effects than those in other countries, suggesting they could better tolerate OCs than the other women. This multicenter study's findings indicates that both Triquilar and Lo-Femenal are effective and safe. In addition, they exhibit good cycle control.

A multicenter clinical trial of a progestin-only oral contraceptive in lactating women.

A non-comparative study of a progestin-only oral contraceptive (POC) containing 75 micrograms norgestrel was conducted at 22 sites in 14 countries. This study was designed to evaluate safety, contraceptive efficacy, and the overall acceptability of a POC in breastfeeding women. A total of 4,088 women entered the study over a three-year period and 29,399 woman-months of experience was gathered. Women had follow-up visits at 2, 6, and 11 months after admission. Headaches and vaginal discharge were the medical complaints most commonly reported by women, both prior to and after admission. Menstrual problems were reported by 59% of the women after admission. Of the 3,714 women who returned for at least one follow-up visit, 1,101 (29.6%) discontinued through month 11. The 11-month total discontinuation percentage, including those lost to follow-up (25.3%) was 51.6%. The most common reason given for discontinuation was a woman's desire for a change in contraceptive method. Only 4.9% discontinued pill use for menstrual problems, a percentage far below those generally reported for POCs. Twenty-nine unintended pregnancies occurred through 11 months giving a gross cumulative life table rate of 1.2 per 100 women (Pearl Index = 1.4). The POC appears to be a safe, effective and acceptable contraceptive option for postpartum breastfeeding women.

A comparative study of 35 mcg and 50 mcg combined oral contraceptives: results from a multicenter clinical trial.

A comparative multicenter clinical trial of two combined oral contraceptives (OCs) differing only in the estrogen content (35 mcg ethinyl estradiol versus 50 mcg mestranol) was conducted at five clinics located in Yugoslavia, Egypt, Sri Lanka, Costa Rica and Mexico. The trial was designed to determine the differences between Norinyl 1+35 (Syntex) and Norinyl 1+50 (Syntex) in rates and reasons of discontinuation, and frequency of selected side effects which might contribute to method discontinuation. This report includes analysis of 1698 women, all of whom were interval patients (at least 42 days but within 26 weeks postpartum), randomly allocated to one of the above OCs between October 1982 and January 1984. Follow-up visits were scheduled at 1, 4, 8 and 12 months after admission. Significantly more women in the Norinyl 1+35 group (p less than .001) reported intermenstrual bleeding (primarily staining and spotting), as well as an increase in the occurrence of intermenstrual bleeding compared to women in the Norinyl 1+50 group. There were no significant differences between the groups for side effects with the exception of more women in the Norinyl 1+50 group (p less than .05) reporting breast discomfort. The lost to follow-up rate at 12 months was 19.3% for both the Norinyl 1+35 and the Norinyl 1+50 groups. The total discontinuation rate (including women lost to follow-up) at 12 months was 43.5% for the Norinyl 1+35 group and 41.0% for the Norinyl 1+50 group. There were no significant differences between the two groups for gross cumulative life table discontinuation rates (p greater than .05). There were six accidental pregnancies attributed to user failure reported during the study period; four in the Norinyl 1+35 group and two in the Norinyl 1+50 group.