DICLOFENAC SODIUM INHIBITS BONE-RESORPTION IN POSTMENOPAUSAL WOMEN

Background: The results of experimental studies with animals indicated that prostaglandins stimulate bone resorption, that skeletal producti on of prostaglandin E, is enhanced by ovariectomy and is diminished by 17 beta-estradiol, and that the nonsteroidal anti-inflammatory drug ( NSAID) naproxyn prevents bone loss after ovariectomy. Studies were car ried out to investigate the effects of the NSAID diclofenac sodium on bone and mineral metabolism in premenopausal women and to compare the effects of diclofenac sodium and conjugated estrogens on bone and mine ral metabolism in postmenopausal women. Patients and methods: Ten heal thy premenopausal women and 17 healthy postmenopausal women were studi ed while not being treated and again after 4 weeks of treatment with d iclofenac sodium, 150 mg per day in divided doses (both groups), and c onjugated estrogens, 0.625 mg per day (postmenopausal women). Cross-li nked N-telopeptides of type I collagen were measured in the urine as a n index of bone resorption. The postmenopausal women were separated in to two groups, responders and nonresponders, based on their response t o conjugated estrogens as assessed by linear discriminant analysis for groups. Conjugated estrogens lowered urinary N-telopeptides of type I collagen in responders, but not in nonresponders. Results: Urinary cr oss-linked N-telopeptides were higher in the eight postmenopausal wome n responders than in the nine postmenopausal nonresponders or in the p remenopausal women, and were not altered by diclofenac sodium in preme nopausal women. In the eight postmenopausal women with higher rates of bone resorption, diclofenac sodium and conjugated estrogens significa ntly lowered both urinary calcium concentration and urinary cross-link ed N-telopeptides. The effects of the two drugs were comparable. Concl usion: The preliminary results demonstrate that, at the dose used, dic lofenac sodium is almost as effective as conjugated estrogens for decr easing bone loss in postmenopausal women. Further studies will be need ed to determine whether diclofenac sodium can prevent postmenopausal b one loss.