Evaluation and therapy of breakthrough bleeding in women using a triphasic oral contraceptive**Supported by grant MA 10428 from the Medical Research Council of Canada, Ottawa, Ontario, Canada, and by Ortho Pharmaceutical Company, Don Mills, Ontario, Canada

Triphasic oral contraceptives: review and comparison of various regimens

OBJECTIVE

To review and compare the risk-benefit profile of triphasic oral contraceptives with that of low-dose monophasic oral contraceptives.

DESIGN

Literature on currently marketed triphasics and monophasics.

PATIENT(S)

Healthy women of reproductive age.

MAIN OUTCOME MEASURE(S)

Comparison of the rationale for development, composition, mechanism, efficacy, menstrual cycle control, side effects, health benefits, and risk-benefit profile.

RESULT(S)

All triphasics contain ethinyl estradiol (0.025-0.040 mg/d) and one of several progestins in doses (0.05-1.0 mg/d) related to their relative potencies, which are substantially lower overall (total dose) than those in monophasics. The triphasics are highly efficacious. In general, menstrual cycle control and side effects are similar in both types, but triphasics containing the newer progestins (desogestrel, gestodene, and norgestimate) have better cycle control and a reduced incidence of androgenic side effects compared with those with norethindrone or levonorgestrel. Both triphasics and monophasics have minimal effects on carbohydrate and lipid metabolism and hemostasis parameters, and therefore comparable low risks of coronary heart disease. The health benefits of triphasics and monophasics are similar and include decreased incidence of unwanted and ectopic pregnancies, ovarian cysts, endometrial and ovarian cancers, benign breast disease, and acute pelvic inflammatory disease; less menstrual blood loss and iron deficiency anemia; and lower frequency of irregular bleeding and menorrhagia.

CONCLUSION(S)

The risk-benefit profiles of both triphasics and monophasics are favorable and similar.

An open-label, multicenter, noncomparative safety and efficacy study of Mircette, a low-dose estrogen-progestin oral contraceptive. The Mircette Study Group

OBJECTIVE

The primary efficacy and safety of Mircette (brand of desogestrel/ethinyl estradiol and ethinyl estradiol), an oral contraceptive containing 150 microg desogestrel and 20 microg ethinyl estradiol given for 21 days, followed by 2 days of placebo and then 5 days 10 microg ethinyl estradiol, was evaluated.

STUDY DESIGN

In a large, open-label, 18-month, multicenter trial, a total of 1143 of 1250 healthy female subjects contributed to the determination of extent of exposure, for an equivalent of 1080.8 woman-years of use.

RESULTS

Absence of withdrawal bleeding occurred in 5.5% of total cycles and intermenstrual bleeding occurred in 12.0% of total cycles. Breakthrough spotting was more common than breakthrough bleeding. The Pearl Index for total pregnancies during treatment was 1.02/100 woman-years. Fewer than 3% of subjects discontinued study participation, primarily because of menstrual problems, indicating that Mircette was an oral contraceptive acceptable to the women studied. Overall 73.6% of all subjects reported one or more adverse events, and a total of 43.9% of subjects reported drug-related adverse events. The most common drug-related adverse events reported included headache (8.5%), breast pain (7.3%), dysmenorrhea (4.2%), and menstrual disorder (4.2%). There were no reports of venous thromboembolic events or of significant changes in blood pressure, lipid metabolism, or serum glucose level.

CONCLUSION

The study confirmed that Mircette is a safe and efficacious oral contraceptive that is well tolerated and acceptable to women who have previously used oral contraceptives, as well as first-time users.