The effects of danazol mefanamic acid, norethistherone and a progesterone-impragnated coil on endometrial prostaglandin concentrations in women with monorrhagia

Abstract

The effects of our four medical treatments have been assessed on menstrual blood loss (MBL) and endometrial prostaglandin (PG) concentrations in 30 women with objectively confirmed menorrhagia. Patients were randomly treated with danazol, 200mg daily (n=6), mefanamic acid, 500mg three times daily during menses (n=8), norethisterone, 5mg twice daily from day 15–25 of the cyle (n=8) or a progesterone-impregnated coil releasing 65ug progesterone daily (n=8). Endometrial biopsies were obtained in the mid-luteal phase before and after treatment in 23 cases, and assayed for PG content using radioimmunoassay. Treatment with norethisterone had no effect on either MBL or the concentration of PGs in the endometrium. MBL was significantly reduced after treatment with mefanamic acid (P=0.05, n=6) and the progesterone coil (P0.05, n=6), was reduced in each of 4 cases treated with danazol in whom endometrial biopsies were available. Although there was no consistent change in endometrial PG cocentrations in either the mefamic acid or danazol groups, the lower MBL after insertion of the progesterone coil was associated with a reduced endometrial content of PGE, PGF 2α and “total” PG (6oxo PGF 1 α +PGE+PGE 2 α )−P=0.05. Wherease the cyclooxygenase inhibitor mefenamic acid is likely to exert its effect on endometrial PGs at the time of menstruation itself, the continous administration of progesterone throught the menstrual cycle could result in both an impairment in estrogen receptor generation leading to reduced estrogen-mediated cyclooxygenase activity, and an increase in endometrial PG metabolism.