Endometriosis as a prognostic factor for cancer survival

Studies have shown an increased risk of malignancies in women with endometriosis. Little is known about the impact of endometriosis on cancer survival. We investigated whether the survival after a diagnosis of a malignancy differs in women with a previously diagnosed endometriosis compared to other women. Women with a first time diagnosis of a malignancy in 1969-2005, were identified using the National Swedish Cancer Register (NSCR). By use of the National Swedish Patient Register (NSPR) we identified all women with a diagnosis of endometriosis during the same period and linked these patients with the data from the NSCR. The cohort comprised 4,278 women with endometriosis and a malignancy, and 41,831 randomly selected matched women without endometriosis. Cox regression was used for all calculations to obtain crude and adjusted cause specific mortality rates, measured as hazard ratios (HR) with 95% confidence intervals (CI). A total of 46,109 women entered the study. There was a statistically significant better survival for women with endometriosis for all malignancies combined (HR=0.92) and for breast cancer (HR=0.86) and ovarian cancer (HR=0.81) specifically. For breast cancer the survival enhancing effect in women with endometriosis decreased with increasing parity. There was poorer survival in malignant melanoma for women with endometriosis (HR=1.52). The survival in a malignancy is better in women with a previously diagnosed endometriosis compared to women without endometriosis especially for breast and ovarian cancers. The prognosis of malignant melanoma is poorer in women with endometriosis.

Human chorionic gonadatropin (hCG) during third trimester pregnancy

OBJECTIVE

Separate reference values were recently established for routine blood samples during last trimester pregnancy. Previously, these were based on blood samples from healthy men or non-pregnant women. Normal changes in variation in the levels of steroid hormones in the last weeks of pregnancy before delivery are also incompletely investigated. This study of the preterm hormone levels was carried out in the search for events leading to increased contractility that might occur in the predelivery weeks and potentially influence the initiation of delivery.

MATERIAL AND METHODS

Blood samples during pregnancy weeks 33, 36 and 39 as well as 1-3 h postpartum were collected from pregnant women (19-39 years, mean age 30) with at least one previous pregnancy without hypertension or pre-eclampsia. All women (n = 135) had had a vaginal delivery and spontaneous start of labour. The blood samples were analysed for serum hCG, oestradiol and progesterone. Postpartum, the values were retrospectively rearranged to correspond with the actual week before the day of delivery.

RESULTS

During the last trimester of normal pregnancy, a gradual increase was found in oestradiol (median 45980 to 82410 pmol/L), progesterone (median 341 to 675 nmol/L) and a gradual decrease in hCG (median 31833 to 19494 IU/L). Furthermore, a significant (p<0.03) decrease in hCG was found from the third to the second week before delivery, while oestradiol and progesterone continued to increase.

CONCLUSIONS

Hormone levels during third-trimester pregnancy have not previously been systematically investigated. Recent data suggest that hCG may have a role as an endogenous tocolytic in normal pregnancy by directly promoting relaxation of uterine contractions. In the present study a significant decrease in serum hCG level was found 2-3 weeks before the spontaneous start of labour. This might contribute to increasing the contractility in the uterine muscle and gradually initiate the onset of labour.

The effect of non-steroidal anti-inflammatory drugs on medical abortion with mifepristone and misoprostol at 13–22 weeks gestation

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit the biosynthesis of prostaglandins and concerns have been expressed that they might attenuate the effects of exogenous prostaglandins. This randomized study was conducted to evaluate whether NSAID given during medical abortion with mifepristone/misoprostol in the second trimester has a negative effect on the efficacy of the abortifacient by prolonging the induction-to-abortion interval.

METHODS

Seventy-four women were treated with the anti-progesterone mifepristone, followed by repeated doses of misoprostol 36-48 h later. They were randomized to receive a prophylactic pain treatment of either paracetamol and codeine or diclofenac with the first dose of misoprostol.

RESULTS

Co-treatment of NSAID with misoprostol did not attenuate the efficacy of mifepristone and misoprostol. There was no significant difference between the NSAID and the non-NSAID group in the induction-to-abortion interval (5.4 versus 6.5 h) or the total doses of misoprostol needed (2 versus 3). The frequency of surgical intervention was similar (55.6 versus 52.6%). Women in the group treated with NSAID required significantly less opiates (P = 0.042).

CONCLUSION

Co-treatment with NSAID and misoprostol does not interfere with the action of mifepristone and/or misoprostol to induce uterine contractions and pregnancy expulsion in medical abortion. Prophylactic NSAID administration reduces the need for opiate injections.

Insulin lispro therapy in pregnancies complicated by type 1 diabetes mellitus

OBJECTIVE

To compare the efficacy and safety of preprandial administration of rapid-acting lispro analogue with regular short-acting insulin to pregnant women with type 1 diabetes.

STUDY DESIGN

Open randomised multicentre study. Women were treated with multiple insulin injections aiming at normoglycaemia. Blood glucose was determined six times daily, HbA(1c) every 4 weeks. Diurnal profiles of blood glucose were analysed at gestational week 14 and during the study period at weeks 21, 28 and 34.

PARTICIPANTS

33 pregnant women with type 1 DM were randomised to treatment with lispro insulin (n=16) or regular insulin (n=17).

RESULTS

Blood glucose was significantly lower (P<0.01) after breakfast in the lispro group, while there were no significant group differences in glycemic control during the rest of the day. Severe hypoglycaemia occurred in two patients in the regular group but biochemical hypoglycaemia (blood glucose <3.0 mmol/l) was more frequent in the lispro than in the regular group (5.5 vs. 3.9%, respectively). HbA(1c) values at inclusion were 6.5 and 6.6% in the lispro and regular group respectively. HbA(1c) values declined during the study period and were similar in both groups. There was no perinatal mortality. Complications during pregnancy, route of delivery and foetal outcome did not differ between the groups. Retinopathy progressed in both groups, one patient in the regular group developed proliferative retinopathy.

CONCLUSION

The results suggest that it is possible to achieve at least as adequate glycemic control with lispro as with regular insulin therapy in type 1 diabetic pregnancies.

Balloon catheter for induction of labor in nulliparous women with prelabor rupture of the membranes at term. A preliminary report

The balloon catheter method has been described as an effective method for cervical ripening hitherto used exclusively before rupture of the membranes. We found it of interest to perform a pilot study of the balloon catheter method after rupture of the membranes. In 18 nulliparous women, with an unripe cervix (Bishop score < or = 5) 48 h after prelabor rupture of the membranes at term, cervical ripening was performed using a 26-gauge balloon catheter. Seventy six percent of these women delivered vaginally. Clinical and neonatal outcome data did not differ as compared with term pregnant women who entered labor spontaneously or had a ripe cervix (Bishop score >5) and labor induced with oxytocin within 48 h after prelabor rupture of the membranes. Despite visualization of a pool of amniotic fluid in the vagina on speculum examination on admission, there was a high proportion of patients with an intact forebag observed during the birth process. This preliminary report indicates that the balloon catheter method might be a well-tolerated, safe, and effective method for induction of labor after rupture of the membranes at term.

Contraceptive efficacy of daily administration of 0.5 mg mifepristone

The antiprogestin mifepristone has shown potential to be used as a contraceptive. If 200 mg mifepristone is administered immediately after ovulation, the endometrium shows sufficient impairment of secretory development to prevent implantation. Low daily doses of mifepristone have been shown to reduce several of the local factors regarded as crucial for implantation in human endometrium. To find out if this regimen is sufficient to prevent pregnancy, 32 women were recruited for a study where 0.5 mg mifepristone was administered daily. A total of 141 cycles were studied. Five pregnancies occurred, which was significantly less than if no contraceptive method had been used. However, the dose chosen did not seem sufficient to act as a contraceptive although it is probably not possible to increase the dose without disturbing ovulation and bleeding pattern.

Contraceptive use of antiprogestin

OBJECTIVES

To study the effect of antiprogestin on ovarian function and endometrial development during the menstrual cycle and the possibility of using these compounds for contraceptive purposes.

METHODS

Administration of different doses of the antiprogestin mifepristone during the menstrual cycle; intermittent measurements of luteinizing hormone, progestin and estrogen in blood and/or urine; endometrial morphology and concentration of markers for endometrial receptivity; efficacy trials of the contraceptive effect of mifepristone.

RESULTS

A high dose of mifepristone administered in the follicular phase will inhibit follicular development. If mifepristone is given immediately after ovulation, the secretory development of the endometrium and the expression of, for instance, leukemia inhibitory factor and integrins will be inhibited. Similar effects on the endometrium are obtained with small weekly doses (2.5 or 5.0 mg) or small daily doses (0.5 mg) of mifepristone, which do not inhibit ovulation. Once-monthly administration of 200 mg mifepristone on the day after ovulation, and emergency postcoital treatment, are highly effective methods for preventing pregnancy. Even 5 mg once weekly has a significant contraceptive effect.

CONCLUSIONS

The antiprogestin mifepristone has a number of effects during the menstrual cycle which makes the compound suitable for contraceptive use. Treatment after a single act of unprotected intercourse, and once-a-month treatment immediately after ovulation, have shown high contraceptive efficacy. A low-dose regimen which does not influence ovulation also has a contraceptive effect, but the efficacy needs to be improved before routine clinical use.

Once-a-month treatment with a combination of mifepristone and the prostaglandin analogue misoprostol

In this two centre study, the efficacy of 200 mg mifepristone orally followed 48 h later by 0.4 mg misoprostol orally for menstrual regulation was investigated. The dose of mifepristone was taken the day before the expected day of menstruation. Each volunteer was planned to participate for up to 6 months. A plasma beta human chorionic gonadotrophin (HCG) was measured on the day of mifepristone intake. The study was disrupted prematurely due to low efficacy. In 125 treatment cycles the overall pregnancy rate was 17.6% (22 pregnancies) and the rate of continuing pregnancies (failure) was 4.0%. Eight women discontinued the study due to bleeding irregularities which were seen in 15 cycles (12%). These effects on bleeding pattern made the timing of treatment day difficult. Late luteal phase treatment with a combination of mifepristone and misoprostol is not adequately effective for menstrual regulation.

Contraceptive efficacy of low doses of mifepristone

OBJECTIVE

To determine whether a 5-mg dose of mifepristone is sufficient to prevent pregnancy.

DESIGN

Clinical study.

SETTING

Academic research center.

SUBJECT(S)

Healthy, fertile, sexually active female volunteers.

INTERVENTION

Volunteers received a 5-mg dose of mifepristone once weekly, starting on cycle day 2, for up to 6 months. This was their only contraceptive method.

MAIN OUTCOME MEASURE(S)

Number of pregnancies.

RESULT(S)

The treatment resulted in a significant decrease in pregnancy rate without affecting the menstrual cycle or causing disturbing side effects.

CONCLUSION(S)

A low dose of mifepristone, which does not inhibit ovulation, reduces fertility significantly by affecting the endometrium. However, the contraceptive effect needs to be improved for the drug to compete with other contraceptive methods.

The effect of various doses of mifepristone on endometrial leukaemia inhibitory factor expression in the midluteal phase--an immunohistochemical study

Leukaemia inhibitory factor (LIF) is a cytokine which plays an obligatory role in mouse blastocyst implantation. In human endometrium, LIF expression is significantly increased in the mid-luteal phase indicating that LIF may also play an important role in the human. We have previously shown that a single dose of 200 mg of mifepristone immediately post-ovulation is an effective contraceptive method, probably due to inhibition of endometrial development and function. The purpose of this study was to investigate the effect of various doses of mifepristone on endometrial LIF expression. A total of 22 fertile, regularly-menstruating women were studied during control and treatment cycles. The subjects were divided into four groups: group I received a single dose of 200 mg of mifepristone on cycle day LH + 2 (n = 7). The subjects in groups II and III were treated with either 5 mg (n = 5) or 2.5 mg (n = 5) once a week for 2 months. Group IV subjects received 0.5 mg per day (n = 5) of mifepristone for 3 months. LIF was measured immunohistochemically in endometrial tissue specimens taken on the corresponding day (cycle day LH + 6 to LH + 8) in hormonally-characterized control and treatment cycles. LIF immunostaining was observed in all controls and located to the cytoplasm of the luminal and glandular epithelial cells and stromal cells. In the treatment cycles the staining of luminal epithelium and stroma was similar to controls, while the glandular staining was reduced in all treatment groups. This study reveals that early luteal phase treatment as well as intermittent or daily low dose treatment with mifepristone reduces endometrial glandular LIF expression at the expected time of implantation. The results further support the contraceptive potential of mifepristone in low doses.

Effect of low daily doses of mifepristone on ovarian function and endometrial development

The effects of low daily doses of the antiprogestin mifepristone (RU 486) on ovarian and endometrial function were studied. The study included one control cycle, three treatment cycles and one follow-up cycle. During the treatment cycles, either 0.1 (n = 5) or 0.5 (n = 5) mg of mifepristone was administered once daily. Urine samples were collected three times weekly during the control and treatment cycles and pregnanediol glucuronide and oestrone glucuronide and luteinizing hormone (LH) were quantified by radioimmunoassay. Blood samples for cortisol measurement were collected once weekly and for serum glycodelin at the onset of menstruation. An endometrial biopsy was obtained in the mid-luteal phase in the control cycle and in the first and third treatment cycles and analysed by morphometric and histochemical methods. Binding of Dolichus biflorus agglutinin (DBA) lectin was measured and expression of progesterone and oestrogen receptors and glycodelin were analysed immunohistochemically. All cycles studied were ovulatory with an LH peak and elevated pregnanediol glucuronide concentrations. Follicular development seemed normal as judged by ultrasound examination. The length of the menstrual cycle and the menstrual bleeding were not significantly altered. Following administration of 0.5 mg mifepristone/day, endometrial development appeared to be slightly retarded and glandular diameter was significantly reduced. Furthermore, significant decreases in DBA lectin binding and endometrial expression of glycodelin were observed. Daily doses of 0.1 mg did not have any significant effect on the endometrium. No differences in oestrogen or progesterone receptor immunoactivity between control and treatment cycles were seen. This study provides further evidence that endometrial function is sensitive even to doses of antiprogestin that are low enough not to disturb ovulation. It remains to be established whether these effects are sufficient to prevent implantation.

The possible use of antiprogestins for contraception

BACKGROUND

A number of compounds, antiprogestins, e.g. mifepristone, onapristone and lilopristone, have been developed which compete with progesterone at the receptor level. One of these, mifepristone, is in combination with a prostaglandin analogue currently in use for termination of early pregnancy. The possibility to use these compounds for contraceptive purposes is presently under evaluation.

METHODS

The possible contraceptive effect of antiprogestins has been evaluated in both clinical and experimental studies.

RESULTS

Administration of antiprogestin during the follicular phase has an inhibitory effect on follicular development and ovulation, and on endometrial development and function if administered during the secretory phase of the menstrual cycle. A high dose of mifepristone, 200 mg, administered immediately following ovulation is highly effective in preventing implantation, most likely due to an effect on endometrial receptivity. It seems that the endometrium is more sensitive to antiprogestin than is the ovulatory process. Low weekly, 2.5 mg to 5 mg, and daily doses, 0.5 mg, of mifepristone did not inhibit ovulation, but a significant effect on endometrial development and especially endometrial function judged from measurement of the expression of a number of markers for endometrial receptivity could be demonstrated.

CONCLUSION

The effect of mifepristone on the endometrium may be sufficient to prevent implantation, and if so, an oral contraceptive method could be developed which has no effect on ovarian function.

Effect of post-coital contraceptive methods on the endometrium and the menstrual cycle

STUDY OBJECTIVE

To evaluate the effect of treatment with ethinylesteradiol-levonorgestrel or danazol on ovarian function, gonadotrophin release and endometrial development during the time when a pregnancy may occur following unprotected intercourse.

METHODS

Women with regular menstrual cycles were followed during one control, one treatment and one follow-up month. The women obtained either a combination of 0.5 mg levonorgestrel and 0.1 mg ethinylestradiol (Yuzpe regimen: n = 16) or 600 mg danazol orally and repeated after 12 hours (n = 16). The treatment was administered on either cycle day (cd) 12 or day LH +2. An endometrial biopsy was obtained once on cd LH +6 to +8 in the subjects treated on cd LH +2 both in control and treatment cycles, and morphometric analysis was performed. The concentrations of LH, pregnandiol (P2G), and estrone (EIG) glucuronide were followed daily in morning urine during control and treatment cycles.

RESULTS

Following treatment with the Yuzpe regimen on cd 12 the LH surge was either undetectable (three subjects), postponed to cd 16 to 22 (three subjects) or cd 38 to 39 (two subjects) with lower P2G and LH levels than in the control cycle. Following preovulatory treatment with danazol, no LH peak could be detected in four subjects and in the remaining four subjects the LH peak varied between cd 13 and cd 24. The mean area under the curve for LH was significantly lower, the levels of EIG were slightly higher and the P2G levels were unaffected in comparison with the control cycle. Neither of the two treatments administered on cd LH +2 affected the hormonal pattern and only a discreet effect on the development of the endometrium was seen after the EE/LNG treatment.

CONCLUSION

The findings indicate that the contraceptive effect of postcoital treatment with EE/LNG and danazol is mainly due to an inhibition or delay of ovulation and insufficient corpus luteum function. The direct effect on the endometrium is limited, if any.

Replens versus dienoestrol cream in the symptomatic treatment of vaginal atrophy in postmenopausal women

OBJECTIVES

This study was designed to evaluate the efficacy of Replens, a non-hormonal moisturizing vaginal gel, on symptoms of vaginal atrophy in postmenopausal women, in comparison with Dienoestrol (Cilag), an oestrogenic vaginal cream.

METHODS

Thirty-nine patients were randomly allocated to either of the two treatments. Replens was given three times a week during the 12 weeks of the study, while Dienoestrol was administered daily during the first 2 weeks and thereafter three times a week. Vaginal dryness index, itching, irritation, dyspareunia, pH and safety were evaluated every week the first month and every month thereafter.

RESULTS

Both treatments had a significant increase on vaginal dryness index as soon as the first week of treatment, and the hormonal compound was significantly better than the non-hormonal one. All symptoms such as itching, irritation and dyspareunia significantly decreased or disappeared without any difference between the two treatments. For pH, no significant difference was seen either in each group or between the two groups. No adverse events related with the two drugs were found.

CONCLUSION

This study shows that Replens applied vaginally three times a week, is a full therapy for all symptoms of vaginal atrophy as well as local estrogen. No serious adverse event was related. Replens is an alternative treatment to local estrogen and perhaps a good complement of systemic HRT in patient suffering from vaginal dryness.

Contraception with anti-progesterone

Anti-progesterones have potential as contraceptives, acting either by the inhibition of ovulation or the inhibition of endometrial development. Clinical studies have shown that once-a-month treatment with Mifepristone in the early luteal phase is an effective contraceptive method, and that emergency post-coital contraception with Mifepristone is at least as effective as other methods currently used. Recent studies indicate that the endometrium is more susceptible to Mifepristone than are the hypothalamic and pituitary regions, and it may therefore be possible to develop a new contraceptive method based on low daily or once-weekly doses of Mifepristone that does not influence ovarian function.

Effect of low weekly doses of mifepristone on ovarian function and endometrial development

The effect of a low dose of mifepristone (RU486) on ovarian and endometrial function was studied in 14 healthy women. The study included one control and two treatment cycles. During the treatment cycles, either 2.5 mg (n = 9) or 5 mg (n = 5) of mifepristone was administered once weekly. The concentration of ovarian steroids and luteinizing hormone (LH) in urine was measured daily, cortisol in blood once weekly and glycodelin (placental protein 14; PP14) at the time of menstruation. Ovarian function was monitored by vaginal ultrasound. An endometrial biopsy was taken in each cycle in the mid-luteal phase, based on self-measurement of the LH peak, or on cycle day 22 if no LH peak could be detected. In the evaluation of the results, the outcome of the enzyme immunoassay of LH was used to date the biopsy. Endometrial progesterone and oestrogen receptors and Dolichus biflorus agglutinin (DBA) lectin binding were measured. Ovulation was not inhibited by treatment with mifepristone, and an LH peak could be determined in all control and treatment cycles. However, in four subjects (one with the higher and three with the lower dose) the follicular phase was prolonged by 6-13 days. The duration of the luteal phase and the concentrations of pregnanediol and oestrone glucuronide were not affected by treatment. A dose of 5 mg, and to a lesser extent 2.5 mg, mifepristone once weekly caused desynchronization of endometrial development. Endometrial progesterone receptor, but not oestrogen receptor, concentration was significantly increased by the higher dose. A significant reduction in DBA-lectin binding and in serum glycodelin concentrations was also found. Thus, low doses of mifepristone do not inhibit ovulation but delay endometrial development and impair secretory activity. Whether these effects are sufficient to prevent implantation remains to be established.

Effects of a single post-ovulatory dose of RU486 on endometrial maturation in the implantation phase

The effect of a single post-ovulatory dose of RU486 on endometrial maturation was studied in the implantation phase. A total of 11 healthy women were followed for one control and one or two treatment cycles. In treatment cycles, a dose of 200 or 400 mg RU486 was administered on day luteinizing hormone (LH)+2. In both control and treatment cycles, an endometrial biopsy was obtained on LH+6 to LH+8. These biopsies were assessed by morphometric and immunohistochemical analyses. The treatment with RU486 did not disturb the normal menstrual rhythm but caused a significant inhibition in the endometrial development. Glandular progesterone receptor staining was significantly more pronounced after RU486 treatment, while there was a reduction in the Dolichos biflorus agglutinin lectin binding, indicating inhibition of the normal secretory transformation of the endometrium. It is likely that these effects on endometrial development and secretory activity represent the basis of the contraceptive effect of post-ovulatory RU486 treatment.

The use of progesterone antagonists in combination with prostaglandin for termination of pregnancy

Antiprogestin alone is not sufficiently effective in terminating early pregnancy to be clinically useful. The only exception seems to be immediate post-ovulatory administration which inhibits endometrial development to an extent that prevents implantation of the fertilized ovum. During early pregnancy the uterus is inactive. Treatment with antiprogestin with result in an increased uterine contractility and a significant increase of myometrial sensitivity to prostaglandin. The effect is probably mainly due to the release of the inhibitory effect of progesterone. Antiprogestin not only activates the uterus, it also causes a ripening of the cervix. The combination of RU486 and either vaginal administration of gemeprost or i.m. injections of nalador provide a safe and effective medical abortion in the first 8 weeks of pregnancy. Recent clinical studies indicate that it may be possible to replace the prostaglandin analogues in current use by the orally active analogue misoprostol. Misoprostol is inexpensive and stable at room temperature and would facilitate the provision of medical abortion with mifepristone. Experimental data also indicate that a combination of RU486 and misoprostol may be developed into an effective once-a-month late luteal method to regulate fertility. Pre-treatment with RU486 is also useful in later stages of gestation. A combination of RU486 and the vaginal administration of gemeprost is a highly effective, safe and simple non-invasive method for terminating both early and late second trimester pregnancy.

Termination of early pregnancy with ZK 98,734: pharmacokinetic behaviour and clinical effect

The antiprogestin RU 486 (mifepristone) is highly effective in inducing early abortion in women only if the compound is combined with a prostaglandin analogue. A new related antiprogestin, ZK 98,734, has been reported in animal studies to be much more potent as an abortifacient than mifepristone, concomitant with less antiglucocorticoid activity. The aim of the present two-centre study was to explore the abortifacient efficacy and plasma concentrations of ZK 98,734 in women seeking abortion. A total of 96 pregnant women with amenorrhoea of < 49 days were treated with oral doses of 12.5, 25, 50 or 100 mg ZK 98,734 twice daily for 4 days. The overall rate of complete abortion and continuing live pregnancies was 68 and 20% respectively, i.e. results comparable with treatment with mifepristone alone. No dose-response relationship was noted. In patients with complete abortion, signs of luteal dysfunction in terms of oestradiol and progesterone production were evident on the fourth treatment day, in contrast to patients with failures. Increased amounts of cortisol and prolactin were found during treatment both in successfully treated patients and failures, whereas aldosterone values remained unaffected. The effect on cortisol may indicate some antiglucocorticoid activity in the human. The concentrations of ZK 98,734 in peripheral blood after 25, 50 and 100 mg twice daily for 4 days were similar. The values were slightly above 0.5 mumol/l on the second day of treatment. Maximal concentrations of 0.7 mumol/l were seen on treatment day 4. Plasma concentrations of ZK 98,734 did not differ in cases of complete abortion and failures.(ABSTRACT TRUNCATED AT 250 WORDS)

Early luteal phase treatment with mifepristone (RU 486) for fertility regulation

Mifepristone (RU 486) is an antiprogestin which interacts with progesterone at the receptor level. Administration of mifepristone immediately after ovulation does not upset the menstrual cycle. However, the maturation and function of the endometrium is inhibited and uterine contractility is changed. To test if these effects are sufficient to prevent implantation, 21 women agreed to use one single treatment with 200 mg mifepristone on day luteinizing hormone (LH) + 2 monthly as their only contraceptive method. The women were treated for 1-12 months. The time of the LH peak was determined in the urine by the women themselves using a rapid LH test (Ovu-quick, Organon). The overall number of cycles studied was 169. In 12 cycles the women were unable to detect the LH peak. In these cycles no treatment was given and the women advised to use barrier methods during the time to menstruation. The remaining 157 cycles with a detectable LH peak were all ovulatory based on plasma progesterone measurement. One pregnancy occurred. On the basis of the time of the LH peak, it was retrospectively calculated that in 124 cycles at least one act of intercourse occurred during the period 3 days before to 1 day after ovulation. The probability of pregnancy in this period of the menstrual cycle is thus 0.008. The women did not complain of any treatment-related side-effects apart from slight bleeding for 2-3 days starting a few days after the day of treatment in 35% of the cycles.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of antihormones on endometrial receptors and protein secretion

The antiestrogen tamoxifen and the antiprogestin RU 486 both interact with respective hormones at the receptor level, RU 486 as a pure antagonist which inhibits endometrial development, the downregulation of estrogen and progesterone receptors and the production of endometrial protein, such as PP14, during the secretory phase of the menstrual cycle. Tamoxifen, on the other hand, has both agonistic and antagonistic action.

Effect of antiprogestin, hCG and a prostaglandin analogue on human uterine contractility

In the present study, the effect of hCG and RU 486 on non-pregnant uterine contractility and the sensitivity of the myometrium to the prostaglandin analogue misoprostol (GD Searle, Chicago, IL, USA) was evaluated. Seven healthy female volunteers participated in the study. Uterine contractility was recorded on cycle day LH+13 in two cycles. After recording the spontaneous contractility, 200 micrograms and 400 micrograms of misoprostol were administered orally at an interval of 45-60 minutes. In the second month, 5,000 IU hCG was administered on cycle day LH+8 and 10,000 hCG on cycle days LH+10 and LH+12, and 200 mg RU 486 on cycle day LH+11, 48 hours prior to the recording. In three women, a third month was included in which the same treatment, except for RU 486, was given. Treatment with hCG delayed menstrual bleeding and resulted in a significant increase in the concentration of plasma progesterone. Following hCG, the degree of uterine contractility was reduced, while after hCG and RU 486 the uterus was significantly more active. In the control cycle and following hCG alone, misoprostol had a slight stimulatory effect. When RU 486 was added, the degree of contractility following misoprostol was 4 to 9 times greater than that found if RU 486 was not given. Late luteal administration of RU 486 is not an effective method of fertility regulation. The results of the present study indicate that a combination of RU 486 and misoprostol will be more suitable for this purpose.

Mode of action of RU 486

RU 486 is a 19-norsteroid which has a specific high affinity binding to the progesterone and glucocorticoid receptor. It is generally accepted that RU 486 acts as a pure progesterone antagonist almost without agonistic activity. RU 486 acts mainly directly on the target organ, such as the endometrium, but also to some extent indirectly through an effect on the pituitary gonadotrophin secretion. The effect of RU 486 during the menstrual cycle is dependent on time of treatment. Treatment before ovulation will result in a prolongation of the proliferative phase of the menstrual cycle, while treatment during the mid- and late luteal phase will invariably induce bleeding, often followed by a second bleeding episode at the expected time of menstruation. The only treatment period which does not influence the menstrual cycle is treatment immediately following ovulation. Treatment during the proliferative phase has no effect on endometrial morphology but inhibits follicular development and delays oestrogen and LH surge. Treatment on the first days following ovulation has no effect on ovarian steroid concentration, but will significantly delay endometrial development, cause a change in the concentration of oestrogen and progesterone receptor concentration enzyme activity and production of substances thought to be progesterone dependent. The change in endometrial development is sufficient to prevent implantation. In mid- and late luteal phase, treatment with RU 486 will result in endometrial shedding in spite of normal progesterone levels. Post-ovulatory treatment with RU 486 will also significantly change uterine contractility. In early pregnancy, withdrawal of progesterone inhibition will result in uterine contractility and a significant increase in the sensitivity of the myometrium to prostaglandin.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of tamoxifen alone and in combination with RU 486 on the endometrium in the mid-luteal phase

The effects of RU 486 combined with tamoxifen and tamoxifen alone on hormonal parameters and endometrial development at the time of implantation were studied. Measurements of cytosolic oestrogen and progesterone receptors in endometrium and placental protein 14 (PP14) in plasma were also included. Three dosage schedules were used: single oral dose of 40 mg tamoxifen alone and in combination with 200 mg RU 486, and 40 mg tamoxifen for three consecutive days starting on the first day after the luteinizing hormone (LH) surge. The combined treatment prolonged the luteal phase (P < 0.05) and increased the plasma levels of progesterone. A single dose of tamoxifen did not affect the bleeding pattern and plasma hormone levels, but raised plasma oestradiol and LH with the 3-day treatment. The endometrium was retarded after the combined and the 3-day treatment with tamoxifen. Concentrations of cytosolic progesterone receptors were higher after the combined therapy, but were unaffected after tamoxifen only. PP14 levels were higher (P < 0.05) after repeated tamoxifen doses than in controls, but were lower with combined treatment. Progesterone and oestrogen are evidently necessary for endometrial maturation during the secretory phase of the menstrual cycle. PP14 levels in plasma cannot be used for clinical assessments of endometrial function because high levels coincide with disturbed endometrial development.

Antiprogestin drugs: research and clinical use in Sweden

The Swedish experience indicates that the combination of RU 486 and vaginal or intramuscular administration of different prostaglandin analogues such as Cervagem, Sulprostone, and 15- methyl PGF2 alpha is a highly effective and safe non-surgical method to terminate early pregnancy. The combined treatment may also be used during the second trimester. In mid- and late second trimester abortion this procedure represents a simple, non-invasive, highly effective method. There are several possibilities by which RU 486 can be used as a contraceptive. We have shown that post-ovulatory administration of RU 486 will effectively inhibit implantation. If the preliminary results are confirmed, treatment with RU 486 once a month on day LH+2 may be an attractive alternative to present contraceptive technology.

Uterine contractility and interaction between prostaglandins and antiprogestins. Clinical implications

It is generally believed that progesterone and PGF2 alpha are of major importance in the regulation of uterine contractility. The results summarized herein indicate that progesterone withdrawal is essential for the changes in uterine contractility normally observed during the secretory phase of the menstrual cycle and that the inactivity of the early pregnant uterus is progesterone dependent. Treatment with the antiprogestin RU486 will convert the inactive early pregnant uterus to an active organ and will increase the sensitivity of the myometrium to prostaglandin. These latter effects of antiprogestin have resulted in the development of highly effective, nonsurgical procedures to terminate early pregnancy based on a combined treatment with RU486 and different PG analogues administered orally, vaginally, or intramuscularly. RU486 also has a softening effect on the cervix as demonstrated in late first trimester of pregnancy. This effect may be useful as pretreatment to vacuum aspiration in late first and early second trimester abortion performed by vacuum aspiration or dilatation and curettage. In prostaglandin-induced second trimester abortions, pretreatment with RU486 will significantly reduce the induction-to-abortion interval and the dose of prostaglandin needed.

Vacuum aspiration for termination of early second trimester pregnancy after treatment with vaginal prostaglandin

Vaginal and intramuscular administration of prostaglandin analogues are routinely used for dilatation of the cervical canal prior to vacuum aspiration in first trimester abortion. Whether the same procedure is also useful during the first weeks of the second trimester has been much less investigated. In the present study, 127 women in the 13th and 14th week of pregnancy were pretreated with 3 mg 9-deoxo-16,16-dimethyl-9-methylene PGE2 administered vaginally 12 hours before surgery. At surgery the cervical canal was dilated to 9.8 mm +/- 2.5 mm (mean +/- SD) and the evacuation of the uterus was uneventful. In 21% of the patients vaginal bleeding occurred prior to the operation. The mean blood loss at surgery was 49 ml and exceeded 100 ml in only 6 patients. Gastrointestinal side effects were rare but analgesic injections were demanded by 29% of the patients during the pretreatment period. No subsequent curettage was performed during the follow-up period but 2 patients (1.6%) were readmitted because of post-abortion endometritis. It can be concluded that after pretreatment with PG, vacuum aspiration can be safely performed during the first weeks of the second trimester.

Regulation of non-pregnant human uterine contractility. Effect of antihormones

Uterine contractility was recorded on cycle day LH+6 to LH+8 in a control and treatment cycle in 14 healthy non-pregnant volunteers. In the treatment cycle the subjects received either 50 mg of the antiprogestin RU 486 daily for three days or 40 mg of the anti-estrogen tamoxifen daily for two days. The treatment started on day LH+2. During the recording, 2 to 5 micrograms PGF2 alpha was administered into the uterine cavity. The plasma levels of progesterone and estrogen were the same in both the control and treatment cycles. RU 486 caused a significant increase in uterine contractility expressed in Montevideo Units (MU) and a decrease in uterine tonus in comparison with corresponding data obtained in the control cycle. Following treatment with tamoxifen, uterine contractility was lower but the difference was not significant. PGF2 alpha invariably caused a stimulation of uterine contractility. However, treatment with the antihormones did not influence the response. The result of the present study indicates that the change in uterine contractility occurring in the latter part of the menstrual cycle and during menstruation is due to progesterone withdrawal.

Uterine contractility during pregnancy and the effect of abortifacient drugs

There are a number of compounds in clinical use for termination of pregnancy. Treatment with all of them will result in increased uterine contractility. PGF2 alpha and PGE2 as well as different prostaglandin analogues all have a direct stimulatory effect on the myometrium, while other compounds such as hypertonic saline and Rivanol seem to act mainly through a stimulation of the endogenous production of PGF2 alpha. Treatment with antiprogestins which compete with progesterone at the receptor level or which inhibit progesterone biosynthesis results in an increased uterine contractility probably through a release from progesterone inhibition. If the withdrawal of progesterone also induces an increased endogenous prostaglandin production is unclear. The medical method to induce abortion which best resembles the physiological events during a spontaneous abortion is probably treatment with antiprogestins (receptor blockers or progesterone biosynthesis inhibitors) followed by prostaglandin.

Oral administration of RU 486 and 9-methylene PGE2 for termination of early pregnancy

It has been shown that the antiprogestin RU 486 increases the sensitivity of the early pregnant human uterus to the stimulatory action of prostaglandin E analogues administered vaginally or intramuscularly. To examine if RU 486 also increases uterine sensitivity to a PGE analogue given orally, two investigative approaches were used in the present study: 1) direct registration of uterine contractions before and after administration of 9-methylene PGE2 in untreated and RU-486-treated early pregnant women; and 2) an efficacy trial involving treatment of pregnant women (amenorrhea of 49 days or less) with 25 mg RU 486 twice daily for three or four days followed by 2.5, 5.0 or 10 mg 9-methylene PGE2, or 600 mg RU486 followed by 10 mg 9-methylene PGE2 administered on day 3 and 4. The results showed that oral 9-methylene PGE2 had a clear stimulatory effect on uterine contractility which was further increased by pretreatment with RU 486. Following 2.5, 5.0 or 10.0 mg 9-methylene PGE2, the frequency of complete abortion was the same, or approximately 80%. The success rate is higher than that generally reported for RU 486 treatment alone. If 600 mg RU 486 was complemented with 10 mg 9-methylene PGE2 administered on both days 3 and 4, the frequency of complete abortion increased to 95%. Side effects were of a mild nature and generally occurred following administration of 9-methylene PGE2. The results of the present study indicate that a combined treatment based on oral administration of both the antiprogestin and the prostaglandin analogue can be developed into a highly effective and simple method to terminate early pregnancy.

The effect of RU 486 administered during the early luteal phase on bleeding pattern, hormonal parameters and endometrium

The purpose of the present study was to investigate the effect of a single dose of RU 486 administered very early in the secretory phase on endometrial development and levels of progesterone receptors, on plasma levels of gonadotrophins and ovarian hormones and on the pattern of menstrual bleeding. Twenty-four regularly menstruating subjects participated and were studied during a control, a treatment and a follow-up cycle. In the treatment cycle, a single dose of 200 mg RU 486 was given in the evening of the second day after the urinary LH peak. Plasma was collected from cycle day 10 until menstruation in both control and treatment cycles. The lengths of the control, treatment and follow-up cycles were equal. Three of the subjects had slight vaginal bleeding in association with RU 486 intake which, however, did not disturb their normal menstrual rhythm. Plasma levels of oestradiol, progesterone and FSH were not affected in the treatment cycle, whereas LH levels increased slightly. The elimination half-life of RU 486 was 28.6 h. An endometrial biopsy was taken 12, 36 or 84 h (LH + 3, LH + 4 and LH + 6) after drug intake (eight subjects in each group) and another biopsy was taken on the corresponding day in the control cycle. The specimens were assessed by morphometric analysis and for cytosolic progesterone receptor concentrations. Endometrial biopsies taken 12 h (on LH + 3) after RU 486 intake contained significantly (P less than 0.001) lower levels of cytosolic progesterone receptors than in the control cycle, but levels at 36 and 84 h were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of tamoxifen on the function and lifespan of the corpus luteum and on subsequent ovarian function

The aim of the present study was to investigate the effects of tamoxifen on pituitary and luteal function and on the bleeding pattern when administered continuously in the secretory phase. The study included 16 women with regular menstrual cycles followed during one control, one treatment and one follow-up cycle. Each volunteer received 20 mg tamoxifen twice daily from cycle day 18 to menstruation in the treatment cycle. The luteal phase was slightly, but significantly prolonged during treatment, and FSH, progesterone, 17-hydroxyprogesterone, 20 alpha- dihydro progesterone, estrone, estrone sulphate and estradiol significantly elevated in comparison with corresponding data during the control cycle. The results indicate that estrogen may be of some importance for the regulation of the life span of the corpus luteum in the human. The significantly elevated levels of pregnanediol glucuronide and estrone glucuronide during the follow-up cycle are most likely a result of either a direct effect of remaining circulating tamoxifen levels on the ovary, or mediated through the increased release of FSH. If estrogens are of importance for the process of implantation, which has recently been suggested in sub-human primates, also in the human remains unclear. Studies on the effect of anti-estrogens on the endometrium during the secretory phase of the cycle are ongoing.

Termination of early human pregnancy with RU 486 (mifepristone) and the prostaglandin analogue sulprostone: a multi-centre, randomized comparison between two treatment regimens

A multi-centre, randomized trial was conducted to compare the efficacy and side-effects of two combination regimens of the antiprogestin RU 486 and the intramuscular PGE2 analogue sulprostone for termination of early pregnancy (amenorrhoea up to 49 days). Women in the 3-day group (n = 125) received 25 mg RU 486 twice daily for 3 days plus a single injection of 0.25 mg sulprostone in the morning of the third day of antiprogestin treatment. In the 4-day group (n = 126), RU 486 was given for 4 days and the sulprostone injection in the morning of the fourth day. Treatment outcome in the two groups was similar. Overall, 88.8% had a complete abortion, 6.8% an incomplete abortion and 2.4% were treatment failures; in the remaining 2% treatment outcome could not be determined. Only three of the six women with treatment failure still had detectable fetal heart activity when the pregnancy was terminated by vacuum aspiration two weeks after the start of treatment. Five of the 17 interventions for incomplete abortion were carried out as emergency procedures because of heavy bleeding; two of these five women were given a blood transfusion. The majority of the curettages (10/17) were performed in one centre. If the data from this centre and the women with undetermined treatment outcome were excluded, the rates for complete abortion, incomplete abortion and treatment failure in the remaining six centres were 93.6, 3.7 and 2.7%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of oral prostaglandin E2 on uterine contractility and outcome of treatment in women receiving RU 486 (mifepristone) for termination of early pregnancy

It has been shown that the antiprogestin RU 486 (mifepristone) increases the sensitivity of the early pregnant human uterus to the stimulatory action of synthetic prostaglandin E (PGE) analogues. To examine if RU 486 also increases uterine sensitivity to the naturally occurring PGE2 given orally, two investigative approaches were used in the present studies: (i) direct registration of uterine contractions before and after PGE2 administration in untreated and RU 486-treated early pregnant women; and (ii) a double-blind, randomized, controlled efficacy trial involving treatment of pregnant women (amenorrhoea of less than or equal to 49 days) with RU 486 (25 mg twice daily for 4 days) and PGE2 (1 mg once or twice) or placebo on the last day of RU 486 treatment. The results indicate that oral PGE2 at the doses employed had little or no stimulatory effect on uterine contractility and that it did not improve the rate of complete abortion achieved with RU 486 alone. Overall, 25 of 42 women (59%) had a complete abortion, 15 women (36%) did not abort and the remaining two had incomplete abortions. Women with complete abortions had significantly lower pretreatment levels of progesterone and a longer duration of induced bleeding than those who did not abort. Thus oral PGE2, when given in clinically acceptable doses, is not a suitable alternative to synthetic PGE analogues for use in combination with RU 486 for termination of early pregnancy.

Vascular changes in the human endometrium following the administration of the progesterone antagonist RU 486

Eleven healthy women were assigned to one of two groups. They received 50 mg RU 486 orally per day either on cycle days 7 to 10 (preovulatory group n = 5) or on cycle days 20 to 23 (postovulatory group, n = 6). An endometrial biopsy was taken on the fourth day of the RU-treatment in the preovulatory group and on the second (n = 2) or fourth (n = 4) treatment day in the postovulatory group. Biopsies from 34 untreated women representing matched samples from early and mid preovulatory phase (n = 10) and mid and late postovulatory phase (n = 24) were used as control. The ultrastructure of the endometrial capillaries was investigated by morphometric methods. The administration of RU 486 during the preovulatory phase did not modify the vascular structure. However, when given in the postovulatory phase, necrosis occurred in the capillary endothelial cells with and without regressive changes of the adjacent stroma. The area and diameter of the capillary lumen and the area of the adventitia was smaller than in the control material (p less than 0.01). The result of the study suggests that RU 486, when administered in the postovulatory phase, directly affects the capillary vessels of the endometrium.

Termination of early pregnancy with RU 486 (mifepristone) in combination with a prostaglandin analogue (sulprostone)

The antiprogestin RU 486 (mifepristone) has been shown to induce abortion when administered in early pregnancy, but the rate of incomplete abortion is high, around 40%. As blockage of the progesterone receptor increases the myometrial sensitivity to prostaglandins, a combination of RU 486 and a prostaglandin E2-analogue was tested for termination of pregnancy. One hundred and sixteen women, with a gestational length of less than 49 days from the first day of the last menstrual period, were treated with a daily dose of 50 or 100 mg RU 486 for 3 to 6 days, complemented with an intramuscular dose of 0.25 mg sulprostone (16-phenoxy-PGE2-sulfonylamide) on the last day of RU 486 treatment. The results confirmed that a reduction of treatment duration to 3 days is just as effective for inducing abortion (91% complete abortion) as a 4-6-day treatment regimen (95% complete abortion). Six patients had an incomplete abortion and in one the pregnancy continued unaffected. Side effects included intense uterine pain after the prostaglandin administration (16%), vomiting associated with the antiprogestin intake (9%) and after the prostaglandin administration (9%). One woman needed emergency curettage due to heavy bleeding. Six percent of the treated patients had a decrease in hemoglobin exceeding 20 g/l during the first week but no patient needed blood transfusion. No serious side effects were recorded.

Prostaglandins and antiprogestins

There is considerable interest in the development of a non-surgical method to terminate early pregnancy. During the three weeks immediately following the first missed menstrual period, several prostaglandin (PG) analogs such as sulprostone, gemeprost and 9-methylene PGE2 have been used to terminate the pregnancy. Prostaglandins, however, at the doses required to induce disruption of the conceptus cause gastrointestinal side effects and uterine pain which are more severe than those subsequent to vacuum aspiration. Treatment with the antiprogestin, mifepristone counteracts the effects of progesterone in pregnancy and thus prevents maintenance of the pregnancy. Mifepristone administered alone causes termination of the pregnancy in most, but not all, cases. In addition to removing the influence of progesterone, mifepristrone also induces regular uterine contractions and significantly increased the sensitivity of the uterus to PG analogs. Mifepristone (50 mg/day) followed by an intramuscular injection of a low dose, (0.25 mg), of sulprostone (approximately 1/6 of the dose of prostaglandin necessary to induce abortion if used alone) was highly effective in terminating early pregnancy, causing complete abortion in 94% of cases. Gastrointestinal side effects were rare and uterine pain significantly less common than if PG analogs were used alone. Subsequently the combination of mifepristone and vaginal administration of gemeprost (0.5-1.0 mg) has been shown to be equally effective Ideally, the PG analog would be administered orally rather than by injection or vaginal administration. Preliminary data indicate that 9-methylene PGE2 but not PEG2 may be suitable for this purpose in combination with mifepristone.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of RU486 administered during the proliferative and secretory phase of the cycle on the bleeding pattern, hormonal parameters and the endometrium

Seventeen healthy women aged 24-45 years with regular menstrual periods, proven fertility and not using steroidal contraceptives or IUD were recruited for the study. The volunteers were followed during one control, one treatment and one follow-up cycle. Daily morning urine samples were obtained during the control and the treatment cycle. The samples were analysed with regard to pregnanediol glucuronide (P2-G), oestrone glucuronide (E1-G), oestradiol (E2), progesterone (P4), LH and creatinine. During the entire 3-month study the subjects kept a record of uterine bleeding and side effects. The subjects received 50 mg RU486 daily either on cycle days 7-10 (n = 7) or on cycle days 20-23 (n = 10). An endometrial biopsy was taken on cycle day 10 in the first group and on cycle days 21-28 in the second group of patients. Treatment during the proliferative phase caused significant prolongation of the cycle length due to a delay of the oestrogen and LH surge. However, once the oestrogen concentration started to increase, the remaining part of the cycle was normal. The length of the follow-up cycle was similar to that of the control cycle. The morphology of the endometrium did not differ from control samples taken from untreated women at the same time of the cycle. All ovulating women (n = 9) treated in the mid-luteal phase started to bleed on the 3rd to 4th day of the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of a vaginal gel containing 9-deoxo-16,16-dimethyl-9-methylene PGE2 for cervical dilatation and pregnancy termination

A stable hydrophilic gel for vaginal administration containing 9-deoxo-16,16-dimethyl-9-methylene PGE2 (9-methylene PGE2) was developed and its clinical usefulness for preoperative cervical dilatation and for termination of first and second trimester pregnancy evaluated in 521 pregnant patients admitted to the hospital for therapeutic abortion. Following vaginal administration of 3 mg of 9-methylene PGE2 gel a peak plasma level of between 3.5 and 10 ng/ml was found 3 to 6 hours following treatment. The "bioavailability" of the drug was in the order of 25-30%. 9-methylene PGE2 was found to be equally effective as 1 mg Cervagem for preoperative cervical dilatation. With a pretreatment period of 3 hours side effects were rare with both compounds. If the pretreatment period was extended to 12 hours the degree of cervical dilatation, but also the frequency of side effects increased significantly. Repeated administration of 9-methylene PGE2 was found to be effective (96% complete abortion) in terminating very early pregnancy provided the total dose was 10 mg or more. During second trimester the minimum effective dose was 4.5 mg of the compound repeated every fourth hour. The results of the present study have shown that with the new gel formulation the amount of 9-methylene PGE2 needed to terminate first and second trimester pregnancy was approximately ten times less in comparison with the previously used lipid base suppositories. The treatment was also associated with a low frequency of side effects.

The effect of the antiprogestin RU 486 on uterine contractility and sensitivity to prostaglandin and oxytocin

The effect of RU 486, a steroid acting as an antiprogestin at the receptor level, on uterine contractility and sensitivity to the prostaglandin analogue, 16-phenoxy-PGE2 methyl sulfonylamide (16-phenoxy-PGE2) and to oxytocin was studied in 29 women in early pregnancy. Seven untreated women at the same stage of pregnancy served as controls. In the untreated women no spontaneous uterine contractility was recorded and the response to 0.25 mg 16-phenoxy-PGE2 was characterized by an increase in uterine tonus with superimposed irregular contractions of low amplitude. Treatment with 25 mg RU 486 twice daily resulted in the appearance of regular uterine contractions at 24 h in two out of five patients and in all patients at 36, 48 and 72 h after the start of RU 486 treatment. The withdrawal of progesterone influence changed the inactive early pregnant uterus into an active organ. Administration of 16-phenoxy-PGE2 caused an obvious stimulation of both frequency and amplitude of the contractions. In addition, the significantly increased sensitivity to the prostaglandin analogue, but not to oxytocin, was already apparent 24 h after the start of RU 486 treatment. We have previously shown that the addition of one intramuscular injection of 16-phenoxy-PGE2 on the fourth day of treatment with RU 486 (25 mg twice daily) significantly increased the abortifacient effect of the antiprogestin during early pregnancy. The present study suggests that a shorter treatment may be possible.

Plasma levels of antiprogestin RU 486 following oral administration to non-pregnant and early pregnant women

RU 486 is a synthetic steroid which acts as an antiprogestin at the receptor level. The clinical usefulness of the compound for menstrual regulation and termination of early pregnancy is currently being evaluated. The aim of the present study was to determine the plasma levels of RU 486 following the oral administration of the compound to 42 pregnant and 10 non-pregnant women. The levels of RU 486 were measured by a radioimmunoassay method which uses chromatography on Sephadex LH 20 columns. The identity of the compound assayed as RU 486 was confirmed, but the presence of small amounts of two highly cross-reacting metabolites (monodemethyl and didemethyl RU 486) in the analyzed fractions could not be excluded. Following the ingestion of a single tablet containing 25 and 50 mg of the compound, a peak plasma value of approximately 3.5 to 4.0 mumol/l in both the pregnant and non-pregnant subjects was reached one to two hours later. The half-lives of elimination were about 20 hours in both the pregnant and the non-pregnant women. Following the repeated oral administration of 50, 100 or 200 mg of RU 486 daily for four days, maximum plasma levels of 2.9, 4.5 and 5.4 mumol/l, respectively, were found. Thus, the increase in plasma levels was not directly proportional to the increase in the dose. No accumulation of RU 486 in the plasma was found, even when the duration of treatment was prolonged to six days. The data partly explain the reported lack of relation between ingested dose and frequency of induced abortion and they may be useful for designing future studies on the use of compound to prevent implantation, induce menstruation or terminate an early pregnancy.

Progesterone receptor blockage. Effect on uterine contractility and early pregnancy

RU 486 is an antiprogestin which acts at the receptor level. In the present study the effect of this compound on uterine contractility and sensitivity during early pregnancy was evaluated in 10 patients. Five patients in the 6th to 7th week of pregnancy received 25 mg RU 486 twice daily for four days. On the fourth day of treatment, uterine contractility was recorded. The remaining five early pregnant patients were untreated and served as control. Withdrawal of progesterone locally by RU 486 treatment resulted in the development of a regular uterine activity which was in sharp contrast to the low level contractility pattern found in the untreated control patients. Also the sensitivity to prostaglandin increased following RU 486 treatment. The efficacy of a sequential therapy of RU 486 and the PGE analogue 16-phenoxy-tetranor-PGE2 methyl sulfonylamide for termination of early pregnancy was also studied. Thirty-four early pregnant women (duration of amenorrhea for up to 49 days) admitted to the hospital for termination of their pregnancy volunteered for the study. The patients received 25 mg RU 486 twice or four times daily for four days. In the morning of the fourth day of RU 486 treatment, a small dose (0.25 mg) of the PGE analogue was given as a single intramuscular injection. The combined treatment resulted in complete abortion in 32 patients (94%). One patient experienced an incomplete abortion and in one patient the pregnancy continued unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)

Termination of very early pregnancy by RU 486--an antiprogestational compound

RU 486, a new antiprogestational compound, was given to 37 women seeking termination of pregnancy and with amenorrhea of 42 days or less. One patient was found at the second follow-up visit to have an extrauterine pregnancy. The patients received either 25 mg, 50 mg or 100 mg RU 486 twice daily for four days. All patients attended three follow-up visits, one, two and five to six weeks after the start of therapy. The start, duration and amount of bleeding as well as plasma progesterone, beta-hCG and cortisol concentrations were determined for each treatment day and at the follow-up visits. All patients but three started to bleed during treatment. Frequency of complete abortion was 61% (22 out of 36 patients). In only three patients was the pregnancy unaffected by treatment. The clinical efficacy of the treatment was not dose-dependent. Most of the patients experienced only minor side effects in terms of mild uterine pain, nausea and vomiting. However, two patients suffered from heavy bleeding requiring blood transfusion and curettage. In the patients with complete abortion, beta-hCG values decreased significantly but not until the first follow-up visit. The plasma progesterone also decreased. The decrease appeared earlier with the higher daily dose of RU 486. Cortisol concentrations increased during treatment with all 3 dosage regimens but the levels remained within the normal range. It is concluded that treatment with RU 486 may provide a novel therapy for "menstrual regulation" but the efficacy of the treatment needs to be improved to compete with alternatives such as vacuum aspiration.

Diurnal variation of uterine contractility

The diurnal uterine activity in four normal women in the secretory phase of their menstrual cycles and one woman suffering from dysmenorrhea were studied in relation to concomitant hormone levels in blood (progesterone, hGH, prolactin, cortisol, vasopressin, and 15-keto-13,14-dihydro-PGF2 alpha). In the four normal women uterine activity decreased after midnight, unrelated to circulating levels of 15-keto-13,14-dihydro-PGF2 alpha. But during a dysmenorrheic episode the uterine hypercontractility pattern correlated well with levels of the PGF2 alpha-metabolite, indicating a role of endogenous-produced PGF2 alpha in this condition. The results demonstrate a diurnal rhythm, possibly related to the wake-sleep cycle. No simple associations were seen between vasopressin, cortisol, prolactin, hGH, the PGF2 alpha-metabolite, and uterine activity.

The possible roles of prostaglandins and related compounds in endometrial bleeding. A mini-review

This mini-review summarizes some aspects of hemostatic defects, with particular reference to endometrial bleeding, both the normal menstruation and some bleeding disorders of the uterus. Two cell types are of particularly great interest in the hemostatic mechanism, viz. the platelet and the vascular endothelial cell. We will therefore start with a brief survey of the roles of platelets and vascular endothelium in hemostasis, and the underlying biochemical events will be discussed, particularly the participation of the arachidonate metabolites: the prostaglandins, the thromboxanes and the leukotrienes. This section is then followed by a brief description of some histological findings in the menstruating endometrium; the normal as well as the pathologically bleeding tissue. The possible roles of arachidonate metabolites in these events will be discussed. Several clinical studies have been published, in which various attempts have been made to treat excessive endometrial bleeding with inhibitors of prostaglandin biosynthesis. The findings in these studies are described. The relevance of this approach and its possible effects on other areas of arachidonic acid metabolism will be discussed. Finally, some studies will be summarized in which various attempts have been made to quantitate and endometrial prostaglandins in different physiological and pathological conditions.

The effect of intravenous and intrauterine administration of prostacyclin on non-pregnant uterine contractility in vivo

Intravenous administration of prostacyclin at a dose of 10 ng/min/kg bodyweight for 10 minutes did not have any effect on non-pregnant human contractility in three subjects. Higher doses were not given due to side effects. Intrauterine administration of PGI2 at doses of 0.3-0.6 micrograms resulted in a gradual stimulation of the myometrial activity. Whether this response is a secondary effect of the vasodilation caused by PGI2 or a direct effect on the myometrium could not be established in these experiments.