Examine use of low-and lower-dose OCs

Are 20 mcg oral contraceptives (OCs) becoming more widely used? IMS Health, a Westport, CT-based pharmaceutical market research firm, pegs new U.S. prescriptions of such pills at 14%, and Contraceptive Technology Update readers see an uptick in their use.

"I am using more 20 mcg pills in my practice for women who have estrogen side effects, women over age 40 who are nonsmokers, women who are being watched for borderline hypertension or elevated cholesterol, and short-term use [12 weeks] for women who do not need it as a birth control method but want to regulate their menses for beginning menopausal changes or vacation schedules," says Theresa Rundell, ARNP, at Klickitat County Health Department in White Salmon, WA.

Some public health facilities have not yet incorporated use of 20 mcg pills into formularies due to cost, as is the case at San Antonio Metropolitan Health District. "The 20 mcg pills are currently too expensive for us to stock," says Janet Realini, MD, MPH, director of family planning. "It is my understanding that they are increasing in popularity and market share in the private practice world, especially among older’ women taking oral contraceptives."

There are currently four 20 mcg pills:

• Alesse, an ethinyl estradiol (EE)/levonorgestrel(LNG) pill from Wyeth-Ayerst Laboratories of Philadelphia;

• Levlite, an EE/LNG formulation from Berlex Laboratories of Wayne, NJ;

• Loestrin, an EE/norethindrone acetate pill from Parke-Davis of Morris Plains, NJ;

• Mircette, an EE/desogestrel OC manufactured by Organon of West Orange, NJ.

When it comes to prescribing for "new start" patients, though, CTU readers continue to rely on a 35 mcg pill, Ortho Tri-Cyclen from Ortho-McNeil Pharmaceuticals of Raritan, NJ. Almost half of CTU readers participating in the newsletter’s 1999 contraception survey picked the pill as first-line contraception for 21-year-old women. (For more results of that survey, see CTU, September 1999, p. 97.)

Direct comparisons of different OC formulations have been limited; however, a new study examines the side effects, cycle control, and continuation rates of women using Alesse, Mircette, or Ortho Tri-Cyclen.1 A grant from Organon supported the randomized open-label multicenter clinical trial. The results? Such side effects as bloating, breast tenderness, and nausea were approximately 50% more common in women using the 35 mcg pill as compared with the 20 mcg preparations.

"The bottom line for our study was that it looks like the [20 mcg] pills have just as good cycle control, and they have statistically significantly less estrogenic side effects," says Michael Rosenberg, MD, MPH, clinical professor of obstetrics and gynecology at the school of medicine and adjunct professor of epidemiology at the school of public health, both at the University of North Carolina at Chapel Hill, and president of Health Decisions, a private research firm in Chapel Hill specializing in reproductive health. Rosenberg served as lead investigator for the trial.

A total of 463 women were randomized to use one of the three products, which were to be used for six menstrual cycles. Both "starters" and "switchers" (those who had used OCs in the previous three months before the study) were included in the investigation. Women were required to be between ages 18 and 50, have a body mass index of 18 to 35, and have regular menstrual cycles of 21 to 38 days.

"In this three-way comparison, we found fewer estrogenic side effects and equivalent cycle control and contraceptive efficacy in users of two 20 mcg EE preparations as compared to women using a 35 mcg EE OC," report the investigators. "The side effect findings were most striking, with consistent and significant elevations of approximately 50% in prevalence of estrogenic side effects in the higher-estrogen preparations."

Ortho Tri-Cyclen is the only OC with an indication for acne treatment approved by the Food and Drug Administration. In this particular study, however, when results from both starters and switchers were combined, no product-specific differences in decrease of acne achieved statistical significance. Self-reported acne decreased in starters by 19% and 43% in Alesse and Mircette users, while increasing 22% in Tri-Cyclen users. In switchers, there was less change, although Mircette users demonstrated a 16% decrease. Alesse users noted no change, and Tri-Cyclen users experienced a 22% increase.

Proper pill-taking is key

While 20-mcg OC formulations might offer fewer estrogenic side effects, the lowered estrogen dose might leave less leeway for "missed pills," says Rosenberg.

"From a clinical perspective, we are going to have to make sure that women know how to use these pills well, that they are counseled well, and that we follow up with them well," he observes.

Rundell gives her patients verbal and written instructions on proper pill use, risks, benefits, side effects, and timing of pill taking. "I especially emphasize timing on 20 mcg pills, as well as minipills, to help control breakthrough bleeding and improve effectiveness," she states.

Reference

1. Rosenberg MJ, Meyers A, Roy V. Efficacy, cycle control, and side effects of low- and lower-dose oral contraceptives: A randomized trial of 20 mcg and 35 mcg estrogen preparations. Contraception 1999; 60:321-329.