Profiles of plasma estrogens, progesterone and their metabolites after oral or vaginal administration of estradiol or progesterone

Risk assessment of growth hormones and antimicrobial residues in meat

Growth promoters including hormonal substances and antibiotics are used legally and illegally in food producing animals for the growth promotion of livestock animals. Hormonal substances still under debate in terms of their human health impacts are estradiol-17β, progesterone, testosterone, zeranol, trenbolone, and melengestrol acetate (MGA) . Many of the risk assessment results of natural steroid hormones have presented negligible impacts when they are used under good veterinary practices. For synthetic hormonelike substances, ADIs and MRLs have been established for food safety along with the approval of animal treatment. Small amounts of antibiotics added to feedstuff present growth promotion effects via the prevention of infectious diseases at doses lower than therapeutic dose. The induction of antimicrobial resistant bacteria and the disruption of normal human intestinal flora are major concerns in terms of human health impact. Regulatory guidance such as ADIs and MRLs fully reflect the impact on human gastrointestinal microflora. However, before deciding on any risk management options, risk assessments of antimicrobial resistance require large-scale evidence regarding the relationship between antimicrobial use in food-producing animals and the occurrence of antimicrobial resistance in human pathogens. In this article, the risk profiles of hormonal and antibacterial growth promoters are provided based on recent toxicity and human exposure information, and recommendations for risk management to prevent human health impacts by the use of growth promoters are also presented.

Intravaginal oestrogen and progestin administration: advantages and disadvantages

The vagina provides a local and a systemic route for delivering hormones for systemic effects and uterine targeting. Due to the 'uterine first-pass effect', hormones concentrate in the uterus and nearby tissues with low systemic exposure. Vaginal oestrogens, progesterone/progestins and danazol are currently used to obtain local (vagina and urethra), regional (uterus, pelvic structures) and systemic effects or contraception. Very low dosages of transvaginal oestrogens in the forms of creams, tablets and rings are effective for vaginal atrophy and urinary incontinence. To avoid endometrial stimulation, no deep vaginal application of low dosages for less than 6 months is recommended. For postmenopausal hormonal therapy by the vaginal route, progesterone is delivered directly to the uterus; the target organ for which it is designed. Worldwide, vaginal progesterone is employed for luteal phase support. Contraceptive vaginal rings offer the advantages of non-oral administration and sustained release. Vaginal administration of steroids is a promising option for the treatment of endometriosis.

Symptoms related to the menopause and sex steroid treatments

In the menopause transition, ovarian steroid production is gradually inhibited and around 35% of women will seek medical help for postmenopausal symptoms. The hot flush is a characteristic manifestation occurring in about 70% of women; it is associated with oestrogen withdrawal and disappears with oestrogen-based hormone replacement therapy. The exact mechanism behind it is still unclear but is probably related to heat loss mechanisms. The flush often occurs in parallel to changes in skin temperature, blood flow, pulse rate and pulses of luteinizing hormone (LH). These are probably secondary to a disturbance in the thermoregulatory centre of the CNS, which is anatomically close to neurons containing gonadotropin-releasing hormone. Depression is no more frequent in the menopausal transition than at other times in life. After surgical menopause, however, oestrogen improves low mood over placebo. In women with premenstrual syndrome, an increased feeling of well-being is associated with the pre-ovulatory oestrogen peak. Progestogens are associated with negative mood changes during the menstrual cycle, oral contraception and postmenopausal replacement therapy. Certain progesterone metabolites are anaesthetic and have anti-epileptic and anxiolytic properties, effects which are mediated via the type A gamma-aminobutyric acid (GABAA) receptor. Oestrogen is associated with increased sensory perception, locomotory activity, limb coordination and balance: this may help explain the increased frequency of bone fractures in the early postmenopausal period. Oestrogen improves memory and performance in patients with mild Alzheimer's dementia and increases epileptic activity in patients with partial epilepsy. These effects can be related to amplifying effects of oestrogen on excitatory amino acids in the CNS.

Effects of estradiol with oral or intravaginal progesterone on risk markers for breast cancer in a postmenopausal monkey model

OBJECTIVE

To evaluate the effects of oral estradiol given with either oral or intravaginal micronized progesterone (P4) on risk biomarkers for breast cancer in a postmenopausal monkey model.

DESIGN

This experiment was a two-way crossover study in which 20 ovariectomized adult female cynomolgus macaques were treated (in equivalent doses for women) with oral estradiol (1 mg/d) + oral micronized P4 (200 mg/d) or intravaginal P4 delivered by Silastic rings (6- to 10-mg/d release rate). Hormone treatments lasted 2 months and were separated by a 1-month washout period. The primary outcome measure was breast epithelial proliferation.

RESULTS

Serum P4 concentrations were significantly greater in subjects receiving oral P4 (10.9 ng/mL) compared with intravaginal P4 (3.8 ng/mL) at 2 to 3 hours after oral dosing (P<0.0001) but not at 24 to 28 hours after oral dosing (2.9 ng/mL for oral P4 vs 3.2 ng/mL for intravaginal P4 at 2 months, P=0.19). Serum estradiol concentrations were significantly lower after oral P4 than after intravaginal P4 (P<0.05 for all time points). Oral P4 resulted in significantly decreased body weight (-2.5%) compared with intravaginal P4 (+3.6%) (P=0.0001). Markers of breast proliferation, sex steroid receptor expression, and endometrial area did not differ significantly between oral P4 and intravaginal P4 treatments (P>0.1 for all).

CONCLUSIONS

Despite different pharmacodynamic profiles, oral and intravaginal P4 had similar effects on biomarkers in the postmenopausal breast.

Vascular endothelial growth factor production by circulating immune cells is elevated in ovarian hyperstimulation syndrome

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic disease manifesting itself by ovarian enlargement and massive ascites with increased peritoneal capillary permeability. Although vascular endothelial growth factor (VEGF) is considered to play the main role in developing OHSS, its precise mechanism remains unclear. In this study, we examined possible roles of circulating immune cells in the pathogenesis of OHSS.

METHODS

Peripheral blood mononuclear cells (PBMC) and plasma were collected from healthy non-pregnant volunteers and from patients receiving ovulation induction for IVF. PBMC were cultured for 48 h. Plasma and/or medium concentrations of VEGF, estradiol and progesterone were measured using enzyme-linked immunosorbent assay and radioimmunoassay kits.

RESULTS

VEGF production by cultured PBMC and plasma concentrations of VEGF taken from patients with early onset OHSS (n = 12) were significantly higher than those in non-pregnant volunteers and patients without OHSS whose oocyte retrieval rates were similar to that of OHSS patients. OHSS patients were further classified into a high plasma VEGF concentration group and a high culture medium VEGF group. There was no significant correlation among VEGF production by PBMC and plasma concentration of VEGF, estradiol or progesterone.

CONCLUSION

Although mechanistic evidence has not been provided, our study does provide new evidence to suggest that circulating immune cells are involved in the pathogenesis of OHSS via VEGF production.

Comparative study of the efficacy and tolerability of two vaginal progesterone formulations, Crinone⁎ 8% gel and Utrogestan† capsules, used for luteal support

OBJECTIVE

To compare the efficacy and tolerability of two different types of vaginal progesterone (P), Crinone 8% gel (Fleet Laboratories Ltd., Watford, United Kingdom) and Utrogestan capsules (Laboratories Besins International, Paris, France), used for luteal support after in vitro fertilization (IVF) cycles.

DESIGN

Cohort study.

SETTING

In Vitro Fertilization Polyclinic, Zagreb, Croatia.

PATIENTS

A total of 285 women aged < or =37 years undergoing IVF-embryo transfer treatment.

INTERVENTIONS

Patients were treated with either Crinone 8% vaginal P gel (90 mg) administered daily, or Utrogestan vaginal capsules (2 x 100 mg) administered three times daily. Progesterone was administered from the day of oocyte retrieval (day 0) to menses or, in a case of pregnancy, until week 12.

MAIN OUTCOME MEASURE

Clinical pregnancy rate. The tolerability and acceptability of both preparations were determined by a questionnaire given to patients.

RESULTS

The similar rates of clinical pregnancies (33.1% vs. 30.9%) [corrected] were obtained by using either Crinone 8% vaginal P gel or Utrogestan vaginal capsules. Overall tolerability and acceptability were significantly better in the Crinone group than in the Utrogestan group.

CONCLUSIONS

The efficacy of the two vaginal P formulations was nearly the same, but the tolerability and acceptability of Crinone 8% gel were superior, in the opinion of patients.

Pharmacology of estrogens and progestogens: influence of different routes of administration

This review comprises the pharmacokinetics and pharmacodynamics of natural and synthetic estrogens and progestogens used in contraception and therapy, with special consideration of hormone replacement therapy. The paper describes the mechanisms of action, the relation between structure and hormonal activity, differences in hormonal pattern and potency, peculiarities in the properties of certain steroids, tissue-specific effects, and the metabolism of the available estrogens and progestogens. The influence of the route of administration on pharmacokinetics, hormonal activity and metabolism is presented, and the effects of oral and transdermal treatment with estrogens on tissues, clinical and serum parameters are compared. The effects of oral, transdermal (patch and gel), intranasal, sublingual, buccal, vaginal, subcutaneous and intramuscular administration of estrogens, as well as of oral, vaginal, transdermal, intranasal, buccal, intramuscular and intrauterine application of progestogens are discussed. The various types of progestogens, their receptor interaction, hormonal pattern and the hormonal activity of certain metabolites are described in detail. The structural formulae, serum concentrations, binding affinities to steroid receptors and serum binding globulins, and the relative potencies of the available estrogens and progestins are presented. Differences in the tissue-specific effects of the various compounds and regimens and their potential implications with the risks and benefits of hormone replacement therapy are discussed.

Different routes of progesterone administration and polycystic ovary syndrome: a review of the literature

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in woman of reproductive age. Although extensive studies have been performed in past decades to investigate the pathobiological mechanisms underlying the unset of this disease, its etiology remains unknown. Progesterone is a hormone of paramount importance in ovulation, implantation and luteal phase support. Low levels of progesterone have been found in the early luteal phase in PCOS patients. Granulosa cells from polycystic ovaries show an altered progesterone production. Moreover, the lack of cyclical exposure to progesterone may have a role in the development of the gonadotropin and androgen abnormalities found in PCOS patients. Ovulation failure and progesterone deficiency may facilitate the hypothalamic-pituitary abnormalities causing the associated disordered luteinizing hormone secretion in PCOS. Progesterone may be administered to PCOS patients in the following cases: to induce withdrawal bleeding, to suppress secretion of luteinizing hormone, in ovulation induction in clomiphene citrate-resistant patients and in luteal phase support in assisted reproduction. We discuss the pharmacologic characteristics of the different routes of progesterone administration with reference to these diverse indications, the therapeutic objectives and patient compliance.

A study to look at hormonal absorption of progesterone cream used in conjunction with transdermal estrogen

Natural progesterone creams are gaining popularity as a possible treatment for menopausal symptoms, and many women may be using them with estrogen. We planned to evaluate, using an open plan study, the systemic absorption of a combination of transdermal estrogen and progesterone. Women applied transdermal progesterone 40 mg and transdermal estrogen 1 mg daily over 48 weeks. Women were assessed at intervals of 12 weeks. Significant increases in plasma levels of progesterone and estradiol were seen after 12 weeks, although only low plasma progesterone levels were found (median 2.5 nmol/l) and no further increase was noted over the remainder of the study period. A significant correlation was found between plasma levels of the two hormone (r = 0.315, p = 0.045). Women reported significant reductions in menopausal symptoms, as measured by the Green Climacteric Scale, after 24 and 48 weeks of combined treatment. There may be similar mechanisms of absorption of the two hormones, although the doses used in our study produced sub-luteal levels of progesterone. There was no evidence of accumulation of progesterone with time, and further study is needed to assess the efficacy and safety of this combination of hormones.

Polymorphisms in genes involved in estrogen and progesterone metabolism and mammographic density changes in women randomized to postmenopausal hormone therapy: results from a pilot study

INTRODUCTION

Mammographic density is a strong independent risk factor for breast cancer, and can be modified by hormonal exposures. Identifying genetic variants that determine increases in mammographic density in hormone users may be important in understanding hormonal carcinogenesis of the breast.

METHODS

We obtained mammograms and DNA from 232 postmenopausal women aged 45 to 75 years who had participated in one of two randomized, double-blind clinical trials with estrogen therapy (104 women, taking 1 mg/day of micronized 17beta-estradiol, E2), combined estrogen and progestin therapy (34 women, taking 17beta-estradiol and 5 mg/day of medroxyprogesterone acetate for 12 days/month) or matching placebos (94 women). Mammographic percentage density (MPD) was measured on baseline and 12-month mammograms with a validated computer-assisted method. We evaluated polymorphisms in genes involved in estrogen metabolism (catechol-O-methyltransferase (COMT (Val158Met)), cytochrome P450 1B1 (CYP1B1 (Val432Leu)), UDP-glucuronosyltransferase 1A1 (UGT1A1 (<7/>or= 7 TA repeats))) and progesterone metabolism (aldo-keto reductase 1C4 (AKR1C4 (Leu311Val))) with changes in MPD.

RESULTS

The adjusted mean change in MPD was +4.6% in the estrogen therapy arm and +7.2% in the combined estrogen and progestin therapy arm, compared with +0.02% in the placebo arm (P = 0.0001). None of the genetic variants predicted mammographic density changes in women using estrogen therapy. Both the AKR1C4 and the CYP1B1 polymorphisms predicted mammographic density change in the combined estrogen and progestin therapy group (P < 0.05). In particular, the eight women carrying one or two low-activity AKR1C4 Val alleles showed a significantly greater increase in MPD (16.7% and 29.3%) than women homozygous for the Leu allele (4.0%).

CONCLUSION

Although based on small numbers, these findings suggest that the magnitude of the increase in mammographic density in women using combined estrogen and progestin therapy may be greater in those with genetically determined lower activity of enzymes that metabolize estrogen and progesterone.

Vaginal administration of oral micronized estradiol results in successful twin pregnancy in a functionally agonadal woman

CASE REPORT

A 31-year-old nulligravid woman seeking fertility treatment with in vitro fertilization and intracytoplasmic sperm injection failed to achieve pregnancy. Supernumerary embryos were cryopreserved for future use. In preparation for the transfer of the frozen embryos, the patient was prescribed hormones, which included pituitary down-regulation with leuprolide acetate, followed by oral micronized estradiol (E2) and vaginal progesterone (P4) suppositories. At the time of embryo transfer (ET) it was noted that the patient had misunderstood her instructions and was administering both her estrogen and progesterone vaginally. Ultrasound examination revealed a well-developed endometrium adequate for ET so the procedure was performed, and at that point she was instructed to use E2 orally as originally prescribed. Two weeks later, her beta-hCG was elevated, and subsequent ultrasound examinations revealed a twin gestation. The pregnancy progressed normally.

CONCLUSION

This patient's hormones were adequately replaced despite vaginal placement of oral medication. Although not commonly prescribed, oral E2 tablets may be administered vaginally in functionally agonadal women preparing for ET, and may serve as an alternative route for women who experience difficulties with oral formulations.

Pharmacokinetics of Natural Progesterone Vaginal Suppository

Natural and synthetic progesterone have been used to treat luteal insufficiency, premenstrual syndrome, and in infertile patients. The transvaginal route has advantages, such as lack of local pain, avoidance of first-pass hepatic metabolism, rapid absorption, high bioavailability and local endometrial effect. The aim of this study was to evaluate the pharmacokinetic of natural progesterone administered as vaginal suppositories of 25, 50 or 100 mg. Thirty-five healthy ovulating patients, 31.54 +/- 1.29 (mean +/- SEM) years old, in the follicular phase of the menstrual cycle (between days 7 and 10) participated in the study. They were separated in three groups and received vaginal suppositories containing either 25, 50 or 100 mg of natural progesterone. Progesterone serum concentration reached maximal levels within 2 or 3 h after the administration and was similar for the three groups (7.27 +/- 2.8 ng/ml; 8.84 +/- 3.14 ng/ml; 9.82 +/- 9.8 ng/ml, respectively). This study demonstrated that vaginally administered progesterone could reach levels that are similar to those obtained in ovulatory and luteal phases. The progesterone regimen for adequate endometrial protection and in vitro fertilization (IVF) programs still remains to be studied.

Medroxyprogesterone acetate antagonizes the effects of estrogen treatment on social and sexual behavior in female macaques

Medroxyprogesterone acetate (MPA) commonly is used in contraception and hormone replacement therapy. However, little is known about its effects within the central nervous system. Using ovariectomized pigtail macaques (Macaca nemestrina), we evaluated the potential for MPA to antagonize estradiol (E2) effects on female sociosexual behavior. Subjects (n = 6) were treated sequentially with placebo, E2 alone, E2 + progesterone (P4), and E2 + MPA. The order of treatments was balanced among subjects, and equimolar quantities of P4 and MPA were administered. During each treatment period, female sexual initiation rates, anxiety-related behavior, and aggression were recorded. Treatment with E2 alone induced a substantial rise in female sexual initiation rates. Although concurrent P4 treatment failed to significantly inhibit sexual behavior, MPA treatment markedly antagonized E2's effects. Neither the E2-only nor the E2 + P4 treatment had an impact on aggression rates, but the E2 + MPA treatment induced a significant rise in this behavior. Both MPA and P4 counteracted the effect of E2 on measures of anxiety. These findings suggest that MPA antagonizes certain behavioral effects of E2 that may be beneficial to women, and that it does so more profoundly or in ways that endogenous P4 does not. The marked increase in aggression seen during MPA treatment suggests that production of negative affect may be a particularly serious side effect of MPA.

Successful pregnancy and delivery after delaying the initiation of progesterone supplementation in a postmenopausal donor oocyte recipient

Progesterone luteal support has become a standard procedure during IVF cycles. Donor egg cycle women without inherent ovarian function require complete hormone replacement, in contrast with women undergoing IVF in which luteal support is used to supplement endogenous progesterone production. Progesterone support is clearly beneficial, although the timing of its initiation can affect overall outcomes. This paper describes a case in which a postmenopausal woman attending for oocyte donation did not receive her first progesterone injection at the correct time. Treatment with progesterone began when she arrived for the transfer of the donor embryos. The two embryos were maintained in culture and one was transferred on day 6 when the delayed progesterone administration had induced a secretory transformation in her endometrium. A single gestation sac was recorded 8 weeks later, and a healthy baby was subsequently born. On the morning of day 6, delayed progesterone supplementation had induced the secretory endometrial transformation typical of the second phase of the menstrual cycle.

Luteal support with vaginal micronized progesterone gel in assisted reproduction

The purpose of this study was to review the rationale for vaginal progesterone treatment as luteal support in IVF, and the clinical experience with vaginal micronized progesterone gel. It was found that luteal support with exogenous progesterone significantly improves implantation and pregnancy rates after IVF. Vaginal administration offers a number of potential advantages over intramuscular injection in terms of tolerability and convenience. The clinical experience with Crinone 8%, a vaginal gel containing 90 mg micronized progesterone in a polycarbophil base, indicates that the use of this preparation is associated with pregnancy rates comparable with those achieved after intramuscular administration of progesterone. Moreover, in studies in which patient preferences have been assessed, significantly higher preferences for vaginal micronized progesterone gel have been reported, compared with intramuscular administration or vaginal suppositories. In conclusion, the vaginal micronized progesterone gel used in this study provided effective and well-tolerated luteal support in women undergoing IVF.

Luteal phase support

Assisted reproductive techniques have become a routine treatment for infertility. The extended use of gonadotrophin-releasing hormone analogues in assisted reproductive techniques has made luteal phase support mandatory, as it has been clearly demonstrated that they alter luteal LH pulsatility. For luteal support, HCG administration, though effective, has a high risk of ovarian hyperstimulation syndrome. Progesterone continues to be the gold standard for supplementation. Vaginal progesterone represents a highly effective alternative to painful intramuscular injections. The vaginal route is mainly characterized by direct delivery of the progesterone to the endometrium, thus producing high levels at the target tissue and a very low incidence of side effects.

Luteal phase support

OBJECTIVE

To develop a consensus regarding the need for luteal phase support during assisted reproductive technology (ART), and to establish the optimal compound and route of administration for this purpose.

DESIGN

Review of the published literature on luteal phase support.

PATIENT(S)

Women undergoing assisted reproductive technologies.

INTERVENTION(S)

Progesterone was administered orally, vaginally, or by intramuscular (i.m.) injection to supplement the luteal phase after assisted reproductive technology (ART).

MAIN OUTCOME MEASURE(S)

Pregnancy following ART. RESULT(S); Gonadotropin releasing hormone (GnRH)-agonist protocols necessitate the use of luteal phase support. Progesterone and human chorionic gonadotrophin (hCG) have both been used for this purpose, with comparable outcomes. Progesterone is the product of choice, however, as it is associated with a lower incidence of ovarian hyperstimulation syndrome (OHSS). Its use is indicated up to the serum pregnancy test. Oral, i.m., and vaginal progesterone preparations are available. Intramuscular and vaginal preparations lead to comparable rates of implantation and clinical pregnancy, despite higher serum progesterone levels after i.m. injection. Oral formulations are inferior products for luteal support. Although widely used, i.m. progesterone is uncomfortable and inconvenient for patients. By contrast, the vaginal progesterone gel (Crinone 8%) is more convenient and easier to use.

CONCLUSION(S)

Progesterone support of the luteal phase in in vitro fertilization (IVF) cycles is indicated, though support beyond the serum pregnancy test may not be needed. The pregnancy rates after vaginal and i.m. progesterone support are comparable, despite higher serum levels after i.m. injection. Patients prefer the vaginal progesterone gel.

Comparison of the efficacy and safety of two formulations of micronized progesterone (Ellios and Utrogestan) used as luteal phase support after in vitro fertilization

OBJECTIVE

To compare the efficacy and the tolerability of two different vaginal formulations of micronized progesterone, Ellios and Utrogestan, used for luteal phase support after an in vitro fertilization (IVF) cycle.

DESIGN

Cohort study.

SETTING

Fertility center in a university hospital. PATIENT(S(: One hundred twenty-three women who underwent IVF/intracytoplasmic sperm injection (ICSI) stimulated cycles from October 1998 to March 2000, who had at least six follicles of > or =14 mm on the day of hCG administration.

INTERVENTION(S)

Patients received Ellios pessaries (2 times 200-mg pessary/day) or Utrogestan capsules (2 x 100-mg capsules, two times a day). Progesterone was administered from the day of oocyte pickup (day 0) until menses or up to 10 weeks in pregnant patients.

MAIN OUTCOME MEASURE(S)

Progesterone levels, pregnancy rate, and tolerability tested by patient questionnaire.

RESULT(S)

The progesterone levels on days 0, 9, 16 were not statistically different between the two formulations. The pregnancy rate were similar in groups 1 and 2 (25.5% vs. 18.6%), whereas tolerance was significantly better in group 1 versus group 2 (vaginal discharge: 43% vs. 82%).

CONCLUSION(S)

The efficacy of the two formulations of progesterone is comparable, although the patient tolerance for Ellios is better.

Natural vaginal progesterone is associated with minimal psychological side effects: a preliminary study

The objective of this study was to evaluate the psychological side effects of a transvaginal natural progesterone gel in hormone replacement therapy (HRT). This 3-month preliminary study was part of a multicenter study previously performed in our center. We enrolled 49 women (ages 18-45 years) with hypothalamic amenorrhea (HA) (n = 40) and premature ovarian failure (POF) (n = 9). Estrogenized patients applied vaginal progesterone gel (4% or 8%) every other day for six doses per month. The Hopkins Symptom Checklist (HSCL), a psychometric profile test, was administered at baseline, day 13 of cycle 2, day 24 of cycle 2, and day 24 of cycle 3. Application of the progesterone gel caused no significant change in HSCL total scores or individual symptom scores for somatization, obsession-compulsion, interpersonal sensitivity, depression, and anxiety. Natural vaginal progesterone gel can be an effective alternative to oral progesterone for women on HRT.

Evaluation of an optimal luteal phase support protocol in IVF

SUBJECT

Luteal phase support has been shown in the past to be an essential part of ovarian stimulation protocols, especially the long protocol. It could be shown that hCG is as effective as is progesterone for luteal phase support but hCG is accompanied by a higher rate of complications.

METHODS

Progesterone can be administered in several routes. The oral, intramuscular (i.m.) and vaginal routes have been chosen frequently in the past. The oral route is ineffective, since progesterone has a low oral bioavailability (<10%), and a high rate of metabolites, which may result in side effects such as somnolence etc. Intramuscular administration provides very high serum levels of progesterone and this route is effective with regard to pregnancy rates. Injection of progesterone, however, is painful and cannot be done by the patient herself. The vaginal route is also effective, progesterone can be administered by the patient herself and progesterone is delivered directly to the uterus, where high levels are achieved (first uterine pass effect).

RESULTS

Several studies could show, in the past, that the vaginal administration of progesterone is effective also with regard to the downregulation of uterine contractions. Crinone 8% Vaginal Gel is especially designed for vaginal use with a special applicator and has to be administered once daily in the morning. It adheres to the vaginal epithelium, and leakage of the gel is substantially reduced as compared to other drugs like capsules or suppositories.

CONCLUSIONS

Since progesterone is as effective as hCG for luteal phase support but provides a higher safety with regard to ovarian hyperstimulation syndromes, and vaginal progesterone is as effective as intramuscular progesterone, vaginal progesterone should be the standard choice for luteal phase support. Crinone 8% seems to be the most comfortable way of vaginal administration of progesterone for luteal phase support in IVF cycles.

Analysis of the bleeding pattern in assisted reproduction cycles with luteal phase supplementation using vaginal micronized progesterone

This study was designed to determine the effects of a vaginal micronized progesterone preparation on bleeding patterns and pregnancy outcomes after in-vitro fertilization and intracytoplasmic sperm injection (IVF-ICSI). The study population consisted of 149 consecutive women who had undergone IVF-ICSI using 'long-protocol' stimulation with buserelin-human menopausal gonadotrophin (HMG). A retrospective chart analysis of computerized medical records was undertaken. Vaginal progesterone (200 mg three times daily) was begun the day before oocyte retrieval and continued for a minimum of 16-19 days following human chorionic gonadotrophin (HCG) administration. Occurrence of bleeding following HCG injection, pregnancy rate and outcomes, and serum concentrations of oestradiol were measured. Women undergoing IVF and embryo transfer with ICSI and using vaginal progesterone for luteal support had normal luteal phase lengths (day of HCG minus day of onset of bleeding). In the absence of pregnancy, bleeding occurred after 19.2 +/- 3.9 days (mean +/- SD). Out of the pregnant group only three women bled within 19 days of HCG administration: two had biochemical pregnancies which spontaneously vanished and one evolved to term. The results reflect the normal bleeding pattern to be expected when vaginal progesterone is used for luteal support in IVF and embryo transfer, an approach whose efficacy has been amply proven. No shortened luteal phases were observed using vaginally administered progesterone.

Experience with progesterone gel for luteal support in a highly successful IVF programme

Efficacy of luteal support from single daily administration of Crinone((R)) 8% (progesterone gel) was tested in 43 women in an IVF programme with historical pregnancy rates >50%. Results were compared with those achieved in 46 women concurrently undergoing IVF and receiving 50 mg i.m. progesterone, and with historical data. Pregnancy rates (PR) were evaluated approximately 2 weeks after undergoing IVF by human chorionic gonadotrophin (HCG) measurement (total PR), by ultrasound 2-4 weeks later (clinical PR), and by counting births. Prior experience with other progesterone formulations was compared with that of Crinone 8%. Demographic and IVF characteristics were comparable for both concurrently treated groups. Total PR, clinical PR and live birth rates were similar for the Crinone and the concurrent i.m. progesterone groups: 31 (72.1%) versus 34 (73.9%); 26 (60.5%) versus 28 (60.9%), and 23 (53.5%) versus 23 (50%) respectively. Clinical PR and live birth rates were also similar to the last data reported to the Society for Assisted Reproduction Therapy. Overall acceptability of Crinone 8% was excellent. Among subjects with prior i.m. injection experience, most patients (69.2%) agreed that the gel was easier to use, less painful (76.9%) and less time-consuming (61.5%) than i.m. injections. In conclusion, Crinone 8% offers an appreciable improvement, as it provides an effective luteal support option that avoids painful i.m. injections.

Comparison of the pharmacokinetics of crinone 8% administered vaginally versus Prometrium administered orally in postmenopausal women(3)

OBJECTIVE

Compare the pharmacokinetics of vaginal progesterone gel (Crinone 8%, 90 mg) with that of oral progesterone (Prometrium, 100 mg).

DESIGN

Open-label, randomized, parallel-group protocol.

SETTING

Outpatient clinic.

PATIENT(S)

Twelve healthy postmenopausal women.

INTERVENTION(S)

Six subjects each were randomized to receive progesterone, which was administered either as 90 mg of progesterone gel (Crinone 8%) given vaginally or 100 mg progesterone in a capsule (Prometrium) given orally.

MAIN OUTCOME MEASUREMENT(S)

Serum progesterone levels were measured by both radioimmunoassay (RIA) and liquid chromatography-mass spectrometry (LC-MS).

RESULT(S)

Progesterone given vaginally resulted in greater bioavailability with less relative variability in absorption than oral progesterone (mean AUC(0-24) = 1.48 +/- 0.16 ng. h/mL per milligram vs. 0.035 +/- 0.0052 ng. h/mL per milligram). Mean C(max) for oral progesterone was much lower than that of vaginal progesterone (i.e., 2.20 +/- 3. 06 ng/mL vs. 10.51 +/- 0.46 ng/mL). Mean T(max) occurred earlier for oral progesterone than for Crinone (1.00 +/- 0.41 hours vs. 7.67 +/- 3.67 hours). Radioimmunoassay is inappropriate for determining serum progesterone levels after oral administration, because it provided erroneously high values that were approximately eightfold higher than those obtained with LC-MS.

CONCLUSION(S)

Crinone (progesterone gel) given vaginally results in greater bioavailability with less relative variability than oral progesterone, thus providing more reliable delivery of progesterone, compared with oral progesterone. Measuring circulating progesterone with use of direct RIA is not appropriate after oral progesterone administration.

Crinone 8% (90 mg) given once daily for progesterone replacement therapy in donor egg cycles

OBJECTIVE

To determine whether once-daily dosing of Crinone 8% (90-mg progesterone vaginal gel; Serono Laboratories, Inc., Norwell, MA) is sufficient for normal endometrial development and pregnancy support.

DESIGN

Prospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

Eighty-six women who required complete progesterone replacement for a donor egg cycle.

INTERVENTION(S)

Crinone 8% (90 mg) once daily or IM progesterone (100 mg) once daily was administered from day 15 onward. Both groups underwent an endometrial biopsy on day 26 of a mock cycle, followed by a second cycle in which ET was performed.

MAIN OUTCOME MEASURE(S)

Endometrial development, serum progesterone levels, pregnancy rates, implantation rates, and bleeding patterns.

RESULT(S)

Mean (+/-SD) serum progesterone levels on day 26 were 11.3+/-6.5 ng/mL in the Crinone group and 65.2+/-12.5 ng/mL in the IM progesterone group. At histologic examination, endometrial biopsy specimens were found to be "in phase" for 100% (42/42) of women in the Crinone group and 95.5% (42/44) of women in the IM progesterone group. Although 8 of 42 patients had serum progesterone levels of <6 ng/mL, there was no correlation with endometrial development. Only 1 patient bled before the 14th day of progesterone therapy, and she went on to be delivered of twins. Clinical pregnancy, ongoing pregnancy, implantation, and miscarriage rates were not statistically different for the Crinone and IM progesterone groups: 45.6% (21/46) versus 52.3% (23/44); 39.1% (18/46) versus 40.9% (18/44); 21.5% (34/158) versus 19% (30/158), and 14.3% (3/21) versus 22% (5/23), respectively. Power was sufficient to detect a 25% difference in clinical pregnancy rates.

CONCLUSION(S)

Crinone 8% administered once daily appears to produce the same endometrial development and pregnancy rates as IM progesterone in women who require complete progesterone replacement, and it does not cause early bleeding.

Crinone 8% vaginal progesterone gel results in lower embryonic implantation efficiency after in vitro fertilization-embryo transfer

OBJECTIVE

To evaluate the outcome of IVF-ET after the use of Crinone 8% (Wyeth-Ayerst Laboratories, Inc., Philadelphia, PA) vaginal progesterone gel and to compare these results with those seen in our program with the use of IM progesterone-in-oil.

DESIGN

Retrospective cohort study.

SETTING

A tertiary referral reproductive medicine unit.

PATIENT(S)

Patients <40 years of age undergoing IVF-ET cycles.

INTERVENTION(S)

Patients were treated with either Crinone 8% vaginal progesterone gel (90 mg) administered daily or IM progesterone-in-oil (50 mg) administered daily.

MAIN OUTCOME MEASURE(S)

Biochemical pregnancy rate, implantation rate, and clinical and ongoing pregnancy rates.

RESULT(S)

The use of Crinone 8% vaginal progesterone gel was associated with a lower implantation rate (16.6% versus 26.2%; odds ratio [OR] = 0.56; 95% confidence interval [CI], 0.35-0.89) compared with the use of IM progesterone-in-oil. Biochemical pregnancies were more common after the use of Crinone 8% vaginal progesterone gel as defined by either biochemical pregnancies per transfer (15.9% versus 5.7%; OR = 3.11; 95% CI, 1.17-8.32) or biochemical pregnancies as a proportion of positive serum hCG titers (29.2% versus 9.8%; OR = 3.80; 95% CI, 1.33-10.86). Clinical pregnancy rates also were lower with the use of Crinone 8% vaginal progesterone gel (36.4% versus 52.9%; OR = 0.51; 95% CI, 0.26-0.99).

CONCLUSION(S)

Implantation efficiency is reduced, as demonstrated by lower embryonic implantation rates and higher biochemical pregnancy rates, when Crinone 8% vaginal progesterone gel rather than IM progesterone-in-oil is used for luteal phase support after IVF-ET.

Micronized progesterone: clinical indications and comparison with current treatments

OBJECTIVE

To integrate and evaluate the pharmacokinetic, endocrine, and clinical effects of micronized progesterone formulations.

DESIGN

Published articles concerning the pharmacokinetics of orally administered progesterone and the potential clinical uses of oral micronized progesterone were reviewed. Results concerning their use for secondary amenorrhea, premenopausal bleeding disorders, luteal phase dysfunction, termination of premature labor, hormone replacement therapy, and premenopausal syndrome are summarized. Critical issues to be resolved through ongoing preclinical and clinical research are highlighted.

RESULT(S)

Because of the enhanced bioavailability of oral micronized progesterone, the compound may be useful for a variety of therapeutic indications. Oral micronized progesterone is available in France, and a formulation recently has been approved in the United States for the treatment of secondary amenorrhea and postmenopausal hormone replacement therapy. A large body of evidence, including the Postmenopausal Estrogen/Progestin Interventions study, suggests that the use of a combination of estrogen and oral micronized progesterone is optimal for long-term hormone replacement therapy. There also are data indicating that oral micronized progesterone could be of potential use for the treatment of premenopausal bleeding disorders, luteal phase disorders, and premature labor.

CONCLUSION(S)

Oral micronized progesterone has widespread clinical potential, particularly for the treatment of secondary amenorrhea and dysfunctional premenopausal bleeding, and as a component of postmenopausal hormone replacement therapy.

Luteal support with micronized progesterone following in-vitro fertilization using a down-regulation protocol with gonadotrophin-releasing hormone agonist: a comparative study between vaginal and oral administration

This study aimed to compare the efficacy of micronized progesterone administered as luteal support following ovulation induction for in-vitro fertilization (IVF)- embryo transfer in cycles using gonadotrophin-releasing hormone agonist, either orally (200 mgx4/day) or vaginally (100 mgx2/day) and to characterize the luteal phase hormonal profile during such treatments. A total of 64 high responder patients requiring intracytoplasmic sperm injection due to male factor infertility were prospectively randomized into two treatment groups. Patients treated orally or vaginally were comparable in age (31.9 +/- 6.1 versus 30.6 +/- 5.2; mean +/- SD), number of oocytes retrieved (17 +/- 8.2 versus 18 +/- 7.0), and number of embryos transferred (3.1 +/- 1.2 versus 2.7 +/- 0.9) per cycle. Following low dose vaginal treatment, a significantly higher implantation rate (30.7 versus 10.7%, P < 0.01), but similar clinical pregnancy rate (47.0 versus 33.3%) and ongoing pregnancy rate (41.1 versus 20.0%) was observed, compared with oral treatment. In conception cycles, luteal serum progesterone and oestrogen concentrations did not differ between the treatment groups. In non-conception cycles, late luteal progesterone concentrations were significantly lower following vaginal treatment. As low dose micronized progesterone administered vaginally is simple, easy and well tolerated, it could be recommended as the method of choice for luteal support, especially for high responder patients at risk for ovarian hyperstimulation syndrome.

Oral versus intramuscular progesterone for in vitro fertilization: a prospective randomized study

OBJECTIVE

To evaluate the efficacy of oral micronized progesterone compared with IM progesterone in oil for luteal support in patients undergoing IVF who are treated with a GnRH agonist.

DESIGN

Randomized prospective clinical trial.

SETTING

University-based IVF center.

PATIENT(S)

Women <40 years of age who were undergoing IVF with luteal GnRH pituitary down-regulation.

INTERVENTION(S)

Patients were randomized to receive either oral micronized progesterone (200 mg three times daily) or IM progesterone (50 mg daily).

MAIN OUTCOME MEASURE(S)

Progesterone levels at standardized days 21 and 28, and pregnancy and embryo implantation rates.

RESULT(S)

Day 21 progesterone levels were 77.6+/-13.2 ng/mL in the IM group and 81.5+/-16.2 ng/mL in the oral group. Day 28 progesterone levels were 76.3+/-15.0 ng/mL in the IM group and 53.6+/-10.1 ng/mL in the oral group. The clinical pregnancy rates were 57.9% and 45.8% for the IM and oral groups, respectively. The implantation rate per embryo was significantly higher in the IM group (40.9%) than in the oral group (18.1%).

CONCLUSION(S)

When used according to our protocols, oral progesterone and IM progesterone result in comparable levels of circulating progesterone. However, oral progesterone results in a reduced implantation rate per embryo.

A new clinical option for hormone replacement therapy in women with secondary amenorrhea: effects of cyclic administration of progesterone from the sustained-release vaginal gel Crinone (4% and 8%) on endometrial morphologic features and withdrawal bleeding

OBJECTIVE

The objective of this study was to evaluate the safety and efficacy of 2 doses of a transvaginal polycarbophil-based progesterone gel (4% and 8%) in hormone replacement therapy.

STUDY DESIGN

This multicenter, randomized, parallel-group, open-label 3-month study included 127 women with secondary amenorrhea. Estrogenized patients applied transvaginal progesterone (4% or 8%) every other day for 6 doses per month. Efficacy was based on endometrial biopsy findings and withdrawal bleeding. McNemar's test was used to compare incidence of adverse events before and during treatment.

RESULTS

Progestational changes were found in 92% (Crinone 4%) and 100% (Crinone 8%) of patients with evaluable biopsies. Withdrawal bleeding was experienced by 81% (Crinone 4%) and 82% (Crinone 8%) of the patients. No patient experienced any serious side effect related to treatment. The incidence of most side effects, including psychologic symptoms, decreased with progesterone treatment compared with estrogen alone therapy. Compliance exceeded 98% for both doses.

CONCLUSIONS

Crinone is a novel, effective, and well-tolerated option for hormone replacement therapy in women with secondary amenorrhea.

The hormonal control of endometrial receptivity: estrogen (E2) and progesterone

While the number of identified substances produced by the ovary increases steadily, it remains remarkable that the sole use of exogenous estrogen (E2) and progesterone (P) can prime optimal endometrial receptivity in women whose ovaries have failed or are absent. Early work showed that a marked leeway existed in the acceptable duration of the E2-only phase of endometrial priming. Subsequently, a sequence of transformations are induced by exogenous progesterone that reproduces classical findings made in the menstrual cycle. Secretory changes in endometrial glands are best seen between the 4th and 6th day of progesterone administration (day 18-20 of an ideal cycle where progesterone exposure starts on day 15). Predecidual changes of the endometrial stroma are apparent starting on the 10th day of progesterone exposure (day 24). Contrary to earlier belief, even maximal alterations in the plasma E2 to progesterone ratio fails to alter the endometrial morphology of either glands or stroma. More recently it has been recognized that E2 and progesterone also affect uterine contractility. It has been postulated that excessively high levels of E2 may increase uterine contractility and adversely affect implantation rates in in-vitro fertilization (IVF). Exogenous progesterone has been shown to exert utero-relaxing effects and it has been hypothesised that progesterone supplementation before embryo transfer (ET) may improve receptivity in IVF.

Cycle dependent variations in transfer of 133xenon from vagina to uterus in rats

The possible existence of an oestrus cycle dependent on local transfer of 133xenon from vagina to uterus was investigated in anaesthetized rats. 133Xenon in saline was infused into the vaginal lumen of rats in oestrous (n = 7) and dioestrous (n = 10). The uterus was removed 3 min after the infusion and the radioactivity in the organ counted, after which the remaining radioactivity in vagina was measured. The results showed that the radioactivity increased in all uteri compared with that of the background. The average transfer, expressed as per cent transfer, from vagina in the dioestrous group (5.5%) was significantly higher (P < 0.01, Mann-Whitney) than in the oestrous group (1.4%). The results suggest that the rate of transfer from vagina to uterus depended on the oestrous cycle. Vaginal treatment of women with progesterone for example, may similarly induce high local concentrations in the uterus. Empirically this is already used after in vitro fertilisation, it may also prevent progesterone induced migraine in menopausal women. The possible cycle dependent variations in the transfer in women should be evaluated.

Randomized, double-blind, dose-ranging study of the endometrial effects of a vaginal progesterone gel in estrogen-treated postmenopausal women

OBJECTIVE

Our purpose was to assess the endometrial effects of two doses of natural progesterone administered by a bioadhesive vaginal gel in estrogen-treated postmenopausal women.

STUDY DESIGN

This was a double-blind, randomized, dose-ranging study of 31 postmenopausal women attending a specialist menopause clinic. Endometrial histologic features, sex steroid hormone concentrations, and vaginal bleeding patterns were assessed during three 28-day cycles of continuous oral conjugated estrogens (0.625 mg/day) and two doses of sequential vaginally administered natural progesterone (45 or 90 mg every 48 hours). Histologic results are presented descriptively. Between-group comparisons of other parameters were made with the use of the Mann-Whitney U and Student t tests.

RESULTS

Secretory endometrium was found in 35 of 41 histologic samples that yielded adequate tissue for diagnosis. There was one case of proliferative endometrium in the 45 mg progesterone group and none in the 90 mg group and no cases of hyperplasia. Mean plasma progesterone concentrations of 4.6 ng/ml and 6.8 ng/ml were achieved in the 45 and 90 mg groups, respectively.

CONCLUSIONS

Very low doses of natural progesterone, when administered vaginally in a bioadhesive gel, cause secretory endometrial transformation in estrogen-treated postmenopausal women.

The first uterine pass effect

The endometrial effects of vaginal progesterone have been found to be unexpectedly reliable. This has led us to suspect that a local direct vagina-to-uterus transport or first uterine pass effect was the basis of the uterine targeting of vaginal progesterone. After vaginal administration of progesterone, uterine tissue concentration has been found to exceed by more than 10-fold the levels achieved by systemic administration, despite plasma levels in the latter case that were more than seven times higher. Similar differences in systemic-to-uterine tissue level ratios have been observed between oral and vaginal administration of danazol. Originally seen as a pharmacological advantage permitting the uterine targeting of vaginally administered substances, it is possible that the first uterine pass effect plays a physiological role in the control of uterine contractile activity through the prostaglandins contained in the semen.

Percutaneous estradiol gel with an intrauterine levonorgestrel releasing device or natural progesterone in hormone replacement therapy

OBJECTIVE

To evaluate the bleeding patterns and clinical compliance associated with postmenopausal amenorrhea-inducing forms of hormone replacement therapy using either percutaneous estradiol-gel and a levonorgestrel-releasing intrauterine device or an oral/vaginal natural progesterone.

METHODS

Sixty postmenopausal women with an intact uterus were followed over 12 months in this open, non-randomised, parallel group study. All patients continuously received a gel containing 1.5 mg of estradiol daily. The women were divided into three groups on the basis of progestin administration. Twenty women (group I) had a levonorgestrel-releasing device (LNG-IUD) inserted at the beginning of the study. Twenty-one women (group II) received oral natural micronised progesterone (oral P) 100 mg daily during 25 calendar days each month, and 19 women (group III) used vaginal natural micronised progesterone (vaginal P) 100-200 mg daily during 25 calendar days each month (higher dose if spotting occurred). Clinic visits were at 0, 3, 6 and 12 months. Bleeding patterns were recorded by the patient in a diary and clinical compliance was evaluated at control visits during the treatment. Symptoms were recorded using a modified Kuppermann index. The serum estradiol concentration was determined at the 0, 6 and 12 month control visits.

RESULTS

80% (n = 16) of the patients in the LNG-IUD group, 67% (n = 14) in the oral P group II and 53% (n = 10) in the vaginal P group were without bleeding at 12 months. Spotting was common during the first 3 months. Symptom relief was good in each group. The LNG-IUD did not cause any serious side-effects. Compliance was good for LNG-IUD and oral progesterone but not for vaginal progesterone.

CONCLUSIONS

Percutaneous estradiol-gel associated with LNG-IUD is an appropriate method of hormone replacement therapy. The combination of oral natural progesterone with estradiol-gel is also useful, although bleeding episodes complicated the treatment in one third of the patients. The vaginal administration of natural progesterone was impractical due to bleeding disorders.

Further data favoring the hypothesis of the uterine first-pass effect of vaginally administered micronized progesterone

Ten infertile women, 28 to 36 years of age, with regular menstrual cycles were treated with oral estradiol valerate and intravaginally administered micronized progesterone under pituitary suppression with leuprolide acetate. Patients underwent endometrial biopsies on cycle days 17 and 28 (luteal phase days 3 and 14) and blood sampling for plasma progesterone and estradiol determinations on cycle days 17, 21 and 26 (luteal phase days 3, 7 and 12). All ten endometrial biopsies on cycle day 17 were in-phase and only two out of ten (20%) were out-of-phase on cycle day 28. This produced an incidence of endometrial luteal phase deficiency that was not different from the 14% found among an infertile general population of 300 women. Midluteal estradiol plasma levels in the study group were similar to those found in a control group of fertile women, but progesterone levels were significantly lower on cycle day 21 in the treatment group. As much as 75% (six out of eight patients) of treated women having in-phase late luteal endometrial biopsies had low midluteal plasma progesterone levels, a situation that is found in only 3% of infertile patients (9/300) or 3.5% (9/258) of those infertile women with normal endometria (p = 0.03). Thus, the present study adds further evidence favoring the current postulate that vaginal micronized progesterone enhances hormone delivery to the uterus and this explains the marked discrepancy between the strong uterine effect and the relatively low plasma progesterone levels.

A morphologist's approach to the vagina--age-related changes and estrogen sensitivity

This paper reviews basic facts on vagina histology and ultrastructure with respect to passage of different substances and drugs through the epithelium. Particular interest is devoted to the action mechanism of topically-applied vaginal estrogen, its binding to receptors in different vaginal cell types, and possible local metabolic routes. Differences in estrogen sensitivity between uterus and vagina are discussed as well as the background for the high vaginal sensitivity.

Influence of route of administration on progesterone metabolism

While inducing similar progesterone levels, the ratio of 5 alpha- and 5 beta-pregnanolone/progesterone plasma concentrations has been dramatically increased after oral as opposed to vaginal administration, in a cross-over study. The known psychotropic effects of 5 alpha- and 5 beta-pregnanolone lead to different indications and precautions for oral and vaginal administration of progesterone.

Formation of ethinylestradiol in postmenopausal women during continuous treatment with a combination of estradiol, estriol and norethisterone acetate

Previous studies indicated that during treatment of postmenopausal women with preparations containing norethisterone, a small proportion of the progestogen is aromatized into ethinylestradiol. We therefore investigated the serum concentrations of estradiol, ethinylestradiol and norethisterone in 25 patients of a gynecological practice who were continuously treated for climacteric complaints with a combination of 2 mg estradiol, 1 mg estriol and 1 mg norethisterone acetate for a time period between 4 months and 6 years. Blood sampling occurred between 1 and 20 h after intake of the last tablet. The mean serum concentration of estradiol was 138 +/- 50 (53-279) pg/ml, of ethinylestradiol 18.1 +/- 13.5 (0-44) pg/ml, and of norethisterone 5.1 +/- 3.5 (0.7-11.6) ng/ml. The serum concentrations of estradiol showed a broad maximum between 1 and 14 h, and those of norethisterone a steep rise to maximum within 1-4 h after intake followed by a subsequent decline. Contrary to this, the ethinylestradiol levels were not related to the time after application indicating that the aromatization of norethisterone mainly occurs in peripheral tissue. There was no correlation between age, body mass index or duration of treatment and the ethinylestradiol levels. It is concluded that in the presence of the high estradiol concentrations the low conversion rate of norethisterone into ethinylestradiol is probably without clinical significance.