Short-term urogenital effects of raloxifene, tamoxifen, and estrogen

OBJECTIVE

The purpose of this study was to assess the urogenital effects of raloxifene, tamoxifen, conjugated equine estrogen, and placebo in healthy postmenopausal women.

STUDY DESIGN

This randomized, double-blind, placebo-controlled study compared the urogenital effects of 0.625 mg of conjugated equine estrogen (n = 15 women), 20 mg of tamoxifen (n = 14 women), 60 mg of raloxifene, (n = 15 women), and placebo (n = 13 women). Evaluations at baseline and evaluations after 20 weeks receiving the drug included a pelvic examination with cytologic evaluation of vagina and urethra, pelvic organ prolapse quantitation, and urethral axis deflection by cotton swab test (only in patients with incontinence [33%]).

RESULTS

Conjugated equine estrogen increased the maturation value of both urethral and vaginal cytologic condition (P =.002, P =.032, respectively). There was a decrease in vaginal maturation value in the raloxifene group (not significant). Two of 8 women in the conjugated equine estrogen group showed evidence of worsening prolapse by pelvic organ prolapse quantitation; the condition of 2 of 8 women improved. In the raloxifene, tamoxifen, and placebo groups 8 of 12 women, 4 of 13 women, and 2 of 11 women had worsening in prolapse scores, respectively, whereas none of the women had improvement. Increased cotton swab deflection was found in 3 of 5 women in the raloxifene group, in 5 of 8 women in the tamoxifen group, in 0 of 4 women in the placebo group, and in 0 of 2 women in the conjugated equine estrogen group. Seventy-five percent of the patients who received raloxifene and 60% of the patients who received tamoxifen had increases in prolapse by any measure (ie, pelvic organ prolapse quantitation or cotton swab or clinical assessment) compared with 18% of the patients in the placebo group and 22% of the patients in the conjugated equine estrogen group (P =.015), although symptoms did not differ among groups.

CONCLUSION

Neither raloxifene nor tamoxifen improve cytohormonal effects in the vagina or urethra, whereas conjugated equine estrogen does. Raloxifene and tamoxifen appear to show worsening prolapse compared with conjugated equine estrogen and placebo. The clinical relevance of these effects is unknown and requires investigation.

Urogenital effects of selective estrogen receptor modulators: a systematic review

OBJECTIVE

Selective estrogen receptor modulators (SERMs) include a relatively large number of compounds, each with different profiles of estrogenic/antiestrogenic actions on the genital tract. The aim of this review was to systematically evaluate all the available data from randomized, controlled studies on the effects of these compounds on pelvic organ prolapse and urinary incontinence.

METHODS

Literature searches were performed using three computerized databases to identify the result of all randomized, controlled trials performed with SERMs having any effects on pelvic floor as an outcome. A manual search was performed on all related articles.

RESULTS

We have identified only one randomized, placebo-controlled trial specifically designed to assess the effect of raloxifene and tamoxifen on the urogenital tract. Most of the data on genitourinary effects of various compounds derive from either questionnaires or adverse events reported during phase III clinical trials. Both tamoxifen and raloxifene appear to increase the incidence of pelvic floor prolapse in one trial, although this was not apparent from the licensing studies data for either of the drugs. Raloxifene does not appear to increase the incidence of urinary incontinence. Levormeloxifene and idoxifene, on the contrary, were noted to increase uterine prolapse and incontinence during phase III trials that prematurely terminated. No data are available on the genitourinary effect of toremifene and on the newer SERMs currently undergoing phase III trials: basedoxifene, lasofoxifene, and arzoxifene.

CONCLUSION

Contrary to their effects in bone, SERMs do not have a class-specific effect on the genitourinary tract. In fact, compounds that are more estrogenic on the uterus such as levormeloxifene and idoxifene also increase the risk of prolapse and incontinence. SERMs can adversely affect the pelvic floor and incontinence but data from urodynamic studies are not yet available. Data on prolapse are contradictory. Given the increased incidence of prolapse and incontinence observed in several licensing trials, more focused research on the effect of these molecules on pelvic floor function is needed.

Extracellular matrix integrity: a possible mechanism for differential clinical effects among selective estrogen receptor modulators and estrogens?

Recent gene microarray studies have illustrated heterogeneity in gene expression changes not only between estrogens and selective estrogen receptor modulators (SERMs), but also across different SERM molecules. In ovariectomized rats, this phenomenon was observed with respect to a number of genes involved in collagen turnover and extracellular matrix (ECM) integrity in the uterus and vaginal tissues. Preliminary mechanistic data suggest that these effects on ECM integrity may have relevance in the context of the effect of estrogens and some SERMs to increase the risk of pelvic organ prolapse and the incidence of urinary incontinence in postmenopausal women. Given the pivotal role of ECM integrity and collagen turnover in other tissues and disease states, these processes may provide a fruitful target for future research into the mechanisms for the heterogeneous pharmacology of estrogens and SERMs across different cell types and target tissues.

Adverse effects of a SERM (Levormeloxifene). Safety parameters and bone mineral density 12 months after treatment withdrawal

OBJECTIVE

Levormeloxifene is a selective estrogen receptor modulator (SERM). The development of the drug was discontinued due to intolerable adverse effects. This paper follow-up on the adverse events in a group of 234 women that was followed for 12 months without treatment after 12 months of treatment with levormeloxifene.

METHODS

Adverse events were recorded at all clinical visits. The double-layer thickness of the uterine endometrium was determined by transvaginal ultrasonography. Endometrial biopsies were obtained by pipelle. The biopsies taken at the entrance to the follow-up phase were taken under hysteroscopy-guidance. Bone mineral density of the total body, lumbar spine (L1-L4), hip and forearm was measured by dual-energy X-ray absorptiometry.

RESULTS

The most prominent adverse event was increased endometrial thickness over the pre-defined threshold of 8 mm. No cases of proliferative endometrium were reported. Following withdrawal of treatment the mean endometrial thickness approached baseline levels in a dose dependent manner. Hysteroscopic examinations showed that levormeloxifene was related to increased incidence of edema, vascularization and cysticity. In the levormeloxifene groups, a total of eight women had utero-vaginal prolapse and five women reported urinary incontinence (including worsening of a previously existing condition). Bone density in the spine and hip approached baseline levels during the 12 months of follow-up without treatment.

CONCLUSION

Endometrial thickening, seen in association with the use of some SERM's, may lead to harmful adverse effects more than 12 months after treatment is initiated. Levormeloxifene prevents the postmenopausal bone loss, but the lowest effective dose is unknown.

Zearalenone intoxication of pigs

Mycotoxicosis due to ingestion of zearalenone was detected on 2 pig farms on the Atherton Tableland in northern Queensland. In one herd of 200 pigs, this resulted from feeding maize which had been stored with a high moisture content. In the other herd of 1400 pigs, it resulted from feeding sorghum grain which was rain affected before harvest. Concentrations of zearalenone in the feeds ranged up to 8 mg/kg. Most prepubertal gilts in the herds displayed enlarged teats and signs of oestrus such as having red, swollen vulvas. In several cases both rectal and vaginal prolapses occurred. On one of the farms, 25 pigs died as a direct result of prolapses. Autopsy of a 3-month-old gilt revealed apparently enlarged ovaries and uterine horns. Sows and boars seemed to be unaffected. Four gilts failed to conceive following mating during the period of zearalenone ingestion, but apart from this and the deaths from prolapses, production of the herds appeared to be unaffected.