A luteolytic effect of a prostaglandin F2 alpha analogue in non-pregnant women?

Four healthy non-pregnant volunteers with regular cycles were exposed to vaginal suppositories containing a PGF2 alpha analogue (ICI 81.008, 500-600 microgram) twice at 24-hour intervals in the early or mid-luteal phase. In comparison to serum progesterone levels of ovulatory control cycles, this treatment caused a significant decrease of serum progesterone combined with a shortening of the length of the luteal phase by 1.4 days. No gastrointestinal or other adverse effects were noticed during this treatment. Administration of ICI 81.008 in the follicular phase interfered neither with ovulation nor with the length or shape of the following luteal phase. Although limited, these data suggest a luteolytic effect of ICI 81.008 in women.