Oral micronized progesterone beneficial for perimenopausal vasomotor symptoms

CHICAGO — Perimenopausal women treated with once-daily oral micronized progesterone experienced reductions in vasomotor symptoms and intensity, with no serious adverse effects, compared with placebo, leading researchers to call for further research on the potential of this therapy in the perimenopausal population.

“Perimenopausal women experience more hot flushes than do menopausal women on a population basis, almost 80%, and they also tend to have a higher prevalence of intense vasomotor symptoms, meaning more than 50 moderate-to-severe intensity hot flushes in a given week,” Jerilynn C. Prior, MD, professor in the department of medicine, division of endocrinology and metabolism, University of British Columbia in Vancouver, Canada, said during a presentation at the Endocrine Society Annual Meeting. “The natural history of hot flushes in perimenopause is a confusing one.”

Prior and colleagues evaluated perimenopausal women aged 35 to 58 years in Canada. Ninety-eight percent of participants reported night sweats more than twice per week and nearly two-thirds had skipped a period. Overall, 189 women were randomly assigned to receive treatment with once-daily placebo or oral micronized progesterone 300 mg at bedtime for 12 weeks. The primary outcome was vasomotor symptom score at 3 months.

“[We chose perimenopausal women because] we already studied menopause and there isn’t any randomized controlled trial data for hot flushes only in perimenopause,” Prior said. “There was a gap in the literature, almost 23% of North American women are now in the perimenopausal age range, so it’s a major problem.”

Women were stratified by “early” (no skipped menstrual flow) or “late” (skipped menstrual flow) perimenopause.

The mean vasomotor symptom score was 12.2 at baseline. At 3 months, vasomotor symptom scores decreased in both groups, but the decrease was more pronounced with oral micronized progesterone vs. placebo (mean score, 5.5 vs. 7.1; P = .191).

“In general, women in late perimenopause had a larger improvement, but they also had higher [baseline vasomotor symptom] scores,” Prior said.

Women assigned oral micronized progesterone exhibited significantly greater self-reported, perceived decreases in vasomotor symptom intensity during the day (P = .014) and night (P < .001) and for total night sweats (P = .023) and number (P = .015).

No serious adverse events occurred and adherence was high. Ninety-three percent of women completed the study and most were very likely to take the oral medication (91.4% of progesterone group vs. 84.4% of placebo group).

“Results of this trial are mixed,” Prior said. “The primary outcome was not statistically significant and we were probably underpowered despite our best efforts. I think there is a clinically important benefit based on what women said. It was well-tolerated and likely to be safe. I think that this is a beneficial study that needs to be repeated with larger numbers but is likely to be helpful now for our patients.” – by Amber Cox

Reference:

Prior JC, et al. OR25-7. Presented at: The Endocrine Society Annual Meeting; March 17-20, 2018; Chicago.

Disclosure: Prior reports no relevant financial disclosures.