Effects of raloxifene hydrochloride on the endometrium of postmenopausal women.
OBJECTIVE
We evaluated subtle endometrial morphologic changes in postmenopausal women assigned to placebo, raloxifene hydrochloride 200 or 600 mg/day, or conjugated estrogens (Premarin 0.625 mg/day) according to a new estrogenicity scoring system. Raloxifene, a new selective estrogen receptor modulator, was not expected to stimulate the endometrium.


METHODS
Baseline and end point endometrial biopsies were performed during this double-blind, placebo-controlled 8-week study. A scoring system that was based on standard glandular and stromal morphologic criteria was used to quantitate estrogen-induced effects. Baseline, end point, and baseline-to-end point changes were analyzed for treatment differences.


RESULTS
Treatment groups were similar at baseline with most women showing no estrogenic effects. At end point, statistically significant moderate and marked estrogenic effects were noted in 77% of estrogen-treated women versus 15% of placebo-treated women versus 0% of raloxifene-treated women.


CONCLUSIONS
As expected, estrogen treatment stimulated postmenopausal endometrium. In contrast, raloxifene did not induce histopathologic evidence of endometrial stimulation in healthy postmenopausal women.
Boss
S M
SM
Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285, USA.
Huster
W J
WJ
Neild
J A
JA
Glant
M D
MD
Eisenhut
C C
CC
Draper
M W
MW
D001706:Biopsy; D004311:Double-Blind Method; D004717:Endometrium / Q000187:drug effects* / Q000473:pathology; D004958:Estradiol / Q000097:blood; D004965:Estrogen Antagonists / Q000627:therapeutic use*; D004966:Estrogens, Conjugated (USP) / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008875:Middle Aged; D010880:Piperidines / Q000627:therapeutic use*; D017698:Postmenopause / Q000097:blood / Q000502:physiology*; D020849:Raloxifene Hydrochloride; D013268:Stimulation, Chemical
D004965:Estrogen Antagonists; D004966:Estrogens, Conjugated (USP); D010880:Piperidines; D020849:Raloxifene Hydrochloride; D004958:Estradiol