Serum levels of progesterone and some of its metabolites including deoxycorticosterone after oral and parenteral administration

Diagnostic and therapeutic use of oral micronized progesterone in endocrinology

Progesterone is a natural steroid hormone, while progestins are synthetic molecules. In the female reproductive system, progesterone contributes to the control of luteinizing hormone and follicle-stimulating hormone secretion and their pulsatility, via its receptors on the kisspeptin, neurokinin B, and dynorphin neurons in the hypothalamus. Progesterone together with estradiol controls the cyclic changes of proliferation and decidualization of the endometrium; exerts anti-mitogenic actions on endometrial epithelial cells; regulates normal menstrual bleeding; contributes to fertilization and pregnancy maintenance; participates in the onset of labor. In addition, it exerts numerous effects on other endocrine systems. Micronized progesterone (MP) is natural progesterone with increased bioavailability, due to its pharmacotechnical micronized structure, which makes it an attractive diagnostic and therapeutic tool. This critical literature review aims to summarize and put forward the potential diagnostic and therapeutic uses of MP in the field of endocrinology. During reproductive life, MP is used for diagnostic purposes in the evaluation of primary or secondary amenorrhea as a challenge test. Moreover, it can be prescribed to women presenting with amenorrhea or oligomenorrhea for induction of withdrawal bleeding, in order to time blood-sampling for diagnostic purposes in early follicular phase. Therapeutically, MP, alone or combined with estrogens, is a useful tool in various endocrine disorders including primary amenorrhea, abnormal uterine bleeding due to disordered ovulation, luteal phase deficiency, premenstrual syndrome, polycystic ovary syndrome, secondary amenorrhea [functional hypothalamic amenorrhea, premature ovarian insufficiency], perimenopause and menopause. When administrated per os, acting as a neurosteroid directly or through its metabolites, it exerts beneficial effects on brain function such as alleviation of symptoms of anxiety and depression, asw well as of sleep problems, while it improves working memory in peri- and menopausal women. Micronized progesterone preserves full potential of progesterone activity, without presenting many of the side-effects of progestins. Although it has been associated with more frequent drowsiness and dizziness, it can be well tolerated with nocturnal administration. Because of its better safety profile, especially with regard to metabolic ailments, breast cancer risk and veno-thromboembolism risk, MP is the preferred option for individuals with an increased risk of cardiovascular and metabolic diseases and of all-cause mortality.

COVID-19 and Progesterone: Part 2. Unraveling High Severity, Immunity Patterns, Immunity grading, Progesterone and its potential clinical use

Severely ill COVID–19 (Corona Virus Disease of 2019) patients have a hyperinflammatory condition with a high concentration of pro-inflammatory cytokines termed the cytokine storm. This milieu is reported to cause acute lung injury, oxygen deprivation, multiorgan damage, critical illness, and often death. Post SARS–CoV–2 (Severe Acute Respiratory Syndrome Coronavirus 2) infection, the fight between the invading virus and the host's immune system would either terminate in recovery, with eradication of the infection and regulation of the immune system; or there would be a continuation of immune attacks even after the virus has been cleared, leading to immune dysregulation and disease. This outcome is chiefly dependent on two factors: (1) the patient's immune response, and (2) sufficiency plus efficiency of the regulator(s). Concerning the first, the present research introduces a framework based on different types of immune responses to SARS–CoV–2 along with known disease examples, and how this relates to varying clinical outcomes and treatment needs for COVID–19 patients. About the second factor of ‘regulator(s)’, part 1 of the manuscript described in depth the regulatory role of progesterone in COVID–19. The present study investigates five immunity patterns and the status of the regulatory hormone progesterone with respect to the two established demographic risk factors for COVID–19 high-severity: male sex, and old age. The study evaluates the status of progesterone as a credible determinant of immune regulation and dysregulation. It duly relates the immunity patterns to clinical outcomes and evinces indications for clinical use of progesterone in COVID–19. It proposes a clear answer to the question: "why are males and old patients most likely to have critical illness due to COVID–19?" The study highlights clinical domains for the use of progesterone in COVID–19. Part 2 of this research introduces the concept of immunity patterns and immunity grading. These concepts herewith provided for the clinical course of COVID–19 also apply to other hyperinflammatory conditions. Possible clinical applications of progesterone to treat critically ill COVID–19 patients will open an avenue for hormonal treatments of infections and other immune-related diseases.

Clinical pharmacology of progestins

INTRODUCTION

In this paper, we report general pharmacological profile and major biological activities of natural progesterone (P) and progestins. The aim of this article consists of synthesizing the principal aspects of pharmacology and metabolism of P and progestins related to the clinical consequences of their use.

METHODS

We review scientific literature on the topic "Progestins", evaluating the most relevant data from original articles, reviews and meta-analyses.

EVIDENCE SYNTHESIS

Progestins represent a specific class of synthetic analogues of P clinically employed (alone or associated with estrogens) to manage several gynaecological conditions, for instance multiple abortions, luteal phase defect, premenstrual syndrome, abnormal uterine bleeding, endometriosis and menopause (for hormone replacement therapy). Besides their use in the field of contraception, many non-contraceptive benefits of estroprogestins are mostly due to the activities of progestins. Pharmacological characteristics, dosage and individual metabolism could be listed among the principal aspects influencing their clinical effects.

CONCLUSIONS

The choice of each progestin according to its pharmacological profile is crucial for the appropriate management of any gynaecological condition. An aware knowledge of these compounds is fundamental to hone medical practice.

Natural history of ovarian high-grade serous carcinoma from time effects of ovulation inhibition and progesterone clearance of p53-defective lesions

High-grade serous carcinoma is the most common and devastating type of ovarian cancer; its etiology, mechanism of malignant transformation, and origin remain controversial. Recent studies have identified secretory cells at the fimbria of the fallopian tube as the cell-of-origin of high-grade serous carcinoma, acquiring TP53 mutation, evolving to tubal precursor lesions, including "p53 signature" and serous tubal intraepithelial carcinoma, and metastasizing to the ovary as clinically evident ovarian cancer. The etiological mechanisms associated with known epidemiological risk factors, i.e., ovulation and retrograde menstruation, have also been suggested. Mutagens and transforming growth factors, such as reactive oxygen species and insulin-like growth factor axis proteins, as well as the apoptosis-rescuing protein hemoglobin are abundantly present in the ovulatory follicular fluid and peritoneum fluid, which bathes the fimbrial epithelium, and induces malignant transformation after repeated exposure. In accordance with the proposed cleansing effect of progesterone from studies on oral contraceptive use or term pregnancy, a recent study indicated that the p53-null tubal epithelial cells are selectively cleared by progesterone depending on its progesterone receptor. In this report, by analyzing different time effects of oral contraceptive use or pregnancy in the prevention of ovarian cancer and by aligning them with the carcinogenic and cleansing clearance concepts of ovulation and progesterone, as well as the fact of progressive loss of progesterone receptor during tubal transformation, we deduced the natural history of ovarian high-grade serous carcinoma. The natural history begins at the first ovulation and spans for more than 30 years, taking 10 years from the normal tubal epithelium to the "p53 signature" status, another 15 years to progesterone receptor negative serous tubal intraepithelial carcinoma, and a final 5+ years to high-grade serous carcinoma. The estimated natural history may help understand the pathogenesis of high-grade serous carcinoma and defines the window for early detection and chemoprevention.

Progesterone in Peri- and Postmenopause: A Review

Around 14.5 million peri- and postmenopausal women currently live in Germany. Moreover, approximately 450 000 women, each with a life expectancy of around 85 years, reach menopause every year in Germany. The challenge is therefore to find a therapy with few side effects which could improve the quality of life of women with menopausal symptoms. The aim of hormone therapy (HT) is to remedy hormone deficiencies using substances that offer the best trade-off between benefits and risks. This is where progesterone has a new and important role to play. Progesterone is one of the most important gestagens. Biologically effective progesterone formulations created with micronization techniques have been used in clinical practice since 1996. Nevertheless, up until 2003 preference was given to synthetic gestagens rather than progesterone. The increased breast cancer hazard ratio of 1.23 reported in the WHI study and of 2 given in the Million Women Study has been associated with the use of synthetic gestagens. In a comparison between synthetic gestagens and progesterone, the E3N Study showed that the transdermal administration of estrogen and progesterone did not lead to an increase in breast cancer rates (RR: 1.08). The administration of progesterone does not change the HDL/LDL cholesterol ratio. Because of its anti-mineralocorticoid effect, progesterone has no impact on carbohydrate metabolism, hemostasis, blood pressure, thrombogenicity and body weight. The administration of 200 mg/day progesterone over 12 days of a menstrual cycle or a daily administration of 100 mg combined with an estrogen are a safe and well-tolerated option to treat menopausal symptoms, with a better benefit risk profile compared to synthetic gestagens.

Pregnancy outcomes in oocyte donation recipients: vaginal gel versus intramuscular injection progesterone replacement

PURPOSE

Compare outcomes with vaginal gel versus intramuscular progesterone replacement in donor oocyte recipients.

METHODS

A single-center retrospective analysis (January 2004-December 2006) evaluated pregnancy outcomes (serum human chorionic gonadotropin, implantation, clinical pregnancy, delivery, total pregnancy loss rates) for 225 recipients of embryos from donor (aged <32 years) oocytes. Vaginal progesterone gel (Crinone® 8%; 90 mg twice daily; n = 105) or intramuscular progesterone (50 mg once daily; n = 120) was started the afternoon of oocyte retrieval and continued until a negative pregnancy test or 10 weeks' gestation.

RESULTS

There were no statistically significant differences between groups for the five pregnancy outcomes; numerical results favored vaginal progesterone in all cases. Confidence intervals showed vaginal gel was within, or <1% from, a noninferiority limit of 10% versus intramuscular progesterone for four of five pregnancy outcomes.

CONCLUSIONS

Pregnancy outcomes were comparable for progesterone replacement with vaginal gel and intramuscular progesterone in an oocyte donation program.

Sustained-release progesterone nanosuspension following intramuscular injection in ovariectomized rats

The production of an intramuscular (IM) injection of natural progesterone would provide a safer solution than using semi synthetic progesterone. However, disadvantages such as low solubility and a short half life prevent the use of natural progesterone. In this study, we formulated a sustained release form of natural progesterone to be given as IM injection. A progesterone nanosuspension (PNS) was first developed and then dispersed in a thermosensitive gel matrix. The selected nanoparticles showed an average particle size of 267 nm and a zeta potential approaching-41 mV. The in vitro release profile of PNS from the F127 plus methyl cellulose gel followed zero order kinetics and correlated linearly with the weight percentage of gel dissolved, demonstrating that the overall rate of release of PNS is controlled by dissolution of the pluronic F127/methyl cellulose (MC) gel (r² > 0.99). The pharmacokinetic parameters of the PNS (6 mg/mL) in pluronic F127/MC gel were evaluated in comparison with the control progesterone suspension. After the administration of PNS in F127/MC gel into the rats, a maximum serum concentration of 22.1 ± 1.9 ng/mL was reached at a T_max of 4.05 ± 0.1 h. The terminal half life was 12.7 ± 0.8 h. The area under the curve AUC_0-∞ of the injected formula was 452.75 ± 42.8 ng·h/mL and the total mean residence time was 18.57 ± 1.44 h. The PNS in gel was significantly different from the control in rate and extent at P < 0.001. The natural progesterone which was nanosized and formulated in a thermosensitive gel significantly sustained the action of natural progesterone so that it could be injected every 36 h instead of every day. Moreover, this formula is expected to provide a much safer choice than the use of semi-synthetic progesterone.

The effect of oral micronized progesterone on hormonal and metabolic parameters in anovulatory patients with polycystic ovary syndrome

OBJECTIVE

To investigate the effects of oral natural micronized P on hormonal and metabolic parameters in patients with polycystic ovary syndrome (PCOS) and to answer the clinical question whether induction of withdrawal bleeding is a necessity for the comparison of hormonal and metabolic data in subjects with PCOS.

DESIGN

Prospective clinical study.

SETTING

Academic medical center.

PATIENT(S)

Twenty-eight reproductive-aged women with PCOS.

MAIN OUTCOME MEASURE(S)

Blood sampling was collected at baseline, after 7 days of oral natural micronized P (200 mg) administration, and after withdrawal bleeding. At these three stages hormonal parameters and homeostasis assessment model (HOMA-IR) index were assessed in all patients.

RESULT(S)

Oral natural micronized P administration did not alter significantly insulin sensitivity index and androgen levels; however, LH was decreased when postbleeding values were compared to baseline. Nevertheless, after oral natural micronized P administration, P and 17alpha-hydroxyprogesterone (17-OHP) concentrations were increased, and HOMA-IR was decreased, whereas androgens levels were not altered, in comparison with baseline.

CONCLUSION(S)

The induction of withdrawal bleeding, with this regimen, does not appear to be a necessity for the assessment of hormonal and metabolic profile in anovulatory women with PCOS.

Mixed-Micellar Proliposomal Systems for Enhanced Oral Delivery of Progesterone

The objective of our study was to develop a mixed-micellar proliposomal formulation of poorly water-soluble drug progesterone and evaluate the dissolution profile and membrane transport. Several formulations of proliposomes were prepared by mixing different concentrations of lipid, progesterone, polysorbate 80, and microcrystalline cellulose. The mixed-micellar formulation of drug:dimyristoyl-phosphatidycholine:polysorbate 80 (1:20:3.3) exhibited the maximum dissolution (75.27%), while pure progesterone resulted in low dissolution. The above formulation showed a 4-fold increase in transport in Caco-2 cells and a 6-fold increase in transport across the everted rat intestinal sac experiments compared with control. Proliposomal formulations enhance the extent of dissolution and membrane transport of progesterone and serve as ideal carriers for oral delivery of drugs with low water solubility.

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.

Administration of progesterone produces mild sedative-like effects in men and women

The goal of this study was to investigate the behavioral and subjective effects of a single dose of progesterone in men and women. Certain metabolites of progesterone (e.g., allopregnanolone) are potent positive allosteric modulators of GABA(A) receptors, and produce sedative-like effects in laboratory animals. This study was designed to examine the acute effects of these neurosteroids in humans. Women (n=7) in their early follicular phase and men (n=10) received intramuscular injections of progesterone (200 mg) or placebo. Dependent measures included plasma levels of progesterone and allopregnanolone, self-report measures of mood and subjective effects and behavioral measures of psychomotor performance. Plasma concentrations of progesterone and allopregnanolone increased reliably and with little intersubject variability after drug administration, and levels were similar in men and women. Administration of progesterone produced small, delayed increases in heart rate and feelings of fatigue, and it impaired smooth eye pursuit. These results suggest that, although the effects are modest and not simply related to plasma concentrations, progesterone and its metabolites can produce sedative-like effects in both men and women.

Physical symptoms in premenstrual syndrome are related to plasma progesterone and desoxycorticosterone

Somatic symptoms in the premenstrual syndrome (PMS) may have an etiology separate from that of the mental symptoms. A disturbance in mineralocorticoid action has been discussed, as mineralocorticoids regulate water balance. Desoxycorticosterone (DOC) is interesting, as it has mineralocorticoid effects and is a precursor to the neurosteroid 5 alpha-pregnan-3 alpha,21-diol-20-one (THDOC). THDOC is a steroid with direct benzodiazepine-like effects on the GABA-A receptor in the brain that is metabolized from DOC within the brain and in the periphery. Ten women with PMS having swelling as a major symptom and eight controls were recruited. They marked, on a validated visual-analog scale, three physical symptoms every evening during one menstrual cycle in conjunction with giving blood samples for progesterone and DOC measurements. DOC showed menstrual cycle-linked variation correlating with progesterone. There was no difference in plasma DOC concentrations between patients and controls. The symptoms reached a maximum 1-3 days before the onset of menstruation, with a delay of 3-6 days after the hormone peak. DOC was less strongly correlated with the symptoms than progesterone. These results do not support the hypothesis that DOC is involved in the etiology of physical symptoms in PMS or that physical and mental symptoms have separate etiologies.

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.

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.

Oral micronized progesterone

This review sought to examine the rationale for selecting an oral micronized progesterone formulation rather than a synthetic progestin for some of the main indications for progestogens. Unopposed estrogen use is associated with a high risk (relative risk, 2.1 to 5.7) of endometrial hyperplasia and adenocarcinoma, and it has been understood for some time that a progestogen must be added for at least 10 to 14 days per month to prevent these effects. However, the most commonly used synthetic progestins, norethisterone and medroxyprogesterone acetate, have been associated with metabolic and vascular side effects (eg, suppression of the vasodilating effect of estrogens) in both experimental and human controlled studies. All comparative studies to date conclude that the side effects of synthetic progestins can be minimized or eliminated through the use of natural progesterone, which is identical to the steroid produced by the corpus luteum. The inconvenience associated with the use of injectable, rectal, or vaginal formulations of natural progesterone can be circumvented by using orally administered micronized progesterone. The bioavailability of micronized progesterone is similar to that of other natural steroids, and interindividual and intraindividual variability of area under the curve is similar to that seen with synthetic progestins. A clear dose-ranging effect has been demonstrated, and long-term protection of the endometrium has been established. Micronized progesterone has been used widely in Europe since 1980 at dosages ranging from 300 mg/d (taken at bedtime) 10 days a month for women wishing regular monthly bleeding to 200 mg 14 days a month or 100 mg 25 days a month for women willing to remain amenorrheic. This therapy is well tolerated, with the only specific side effect being mild and transient drowsiness, an effect minimized by taking the drug at bedtime. The prospective, comparative Postmenopausal Estrogens/Progestin Intervention trial has recommended oral micronized progesterone as the first choice for opposing estrogen therapy in nonhysterectomized postmenopausal women.

Pharmacokinetics of progesterone in postmenopausal women: 1. Pharmacokinetics following intravaginal administration

Progesterone was administered to postmenopausal women in a form of vaginal suppositories containing 100 and 200 mg active substance in Butyrum cacao (BC) and Massa estarinum (ME), a base with emulsifying properties. In the case of single doses, blood samples were taken at 2, 4, 6, 24, 48 and 72 h. Another group of patients received vaginal suppositories (100 mg progesterone) once a day for a 6 day period, with blood samples taken 12 h after each administration. The plasma levels of progesterone were evaluated by radioimmunoassay. The time of maximum concentration (tmax) was 4 h in most cases, and 6 h in the others. The plasma levels were not dose-proportional. Peak plasma concentrations were in the range of 10-15 ng/ml with a mean of 10.5 ng/ml for the 100 mg and 12 ng/ml for the 200 mg doses. The ratio of the mean area under the curve (AUC) for 200 mg and the mean AUC for the 100 mg dose was found to be 1.37. Replacing BC with ME resulted in the lowering of cmax and AUC, and an increase in tmax following a reducing in the rate and extent of adsorption. In the case of ME suppositories, the variability in AUC, cmax and tmax was greater compared to that observed with the BC suppositories. Elimination half-time was in the range of 9-10 h for BC and 14 h for ME suppositories. In vitro assessment of the release kinetics from a hydrophobic and an emulsion type base confirmed previous findings: the latter base assured better pharmaceutical availability. The repeated doses did not seem to produce an accumulation of progesterone in the plasma. On the contrary, a small decrease in plasma levels over time appeared during the 6 day period. Numerical analysis revealed an excellent goodness of fit for the in vivo experimental data via biexponential curves, i.e. a pseudomonocompartmental model.

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.

Progesterone-induced changes in sleep in male subjects

Progesterone administration induces a reduction of the vigilance state in humans during wakefulness. It has been been suggested that this effect is mediated via neuroactive metabolites that interact with the gamma-aminobutyric, acidA (GABAA) receptor complex. To investigate the effects of progesterone administration on the sleep electroencephalogram (EEG) in humans we made polysomnographic recordings, including sleep stage-specific spectral analysis, and concomitantly measured plasma concentrations of progesterone and its GABA-active metabolites 3 alpha-hydroxy-5 alpha-dihydroprogesterone (allopregnanolone) and 3 alpha-hydroxy-5 beta-dihydroprogesterone (pregnanolone) in nine healthy male subjects in a double-blind placebo-controlled crossover study. Progesterone administration at 9:30 PM induced a significant increase in the amount of non-rapid eye movement (REM) sleep. The EEG spectral power during non-REM sleep showed a significant decrease in the slow wave frequency range (0.4-4.3 Hz), whereas the spectral power in the higher frequency range (> 15 Hz) tended to be elevated. Some of the observed changes in sleep architecture and sleep-EEG power spectra are similar to those induced by agonistic modulators of the GABAA receptor complex and appear to be mediated in part via the conversion of progesterone into its GABA-active metabolites.

Orally administered progesterone enhances sensitivity to triazolam in postmenopausal women

An endogenously formed metabolite of progesterone, 3 alpha-hydroxy-5 alpha-dihydroprogesterone (3 alpha-OH-5 alpha-DHP) modulates the gamma-aminobutyric acid receptor complex and plays a physiologic role in brain excitability regulation. On the basis of in vitro observations of 3 alpha-OH-5 alpha-DHP-enhanced [3H]flunitrazepam binding, we investigated the potential clinical effect of coadministering oral progesterone and triazolam. Sixteen postmenopausal women were randomly assigned to receive either intravenous triazolam plus oral progesterone 300 mg (TRZPROG) or intravenous triazolam plus oral placebo (TRZ). Triazolam was infused until 0.5 mg was given or until a predetermined maximal response was attained. Pharmacodynamic evaluation included DSST, continuous performance test, hand-eye coordination, short-term memory, and sedation. Effect ratios were calculated as the ratio of area under the effect-time curve to area under the curve (AUC). Variants of the sigmoid Emax model were fit to the data from the three psychomotor performance tests. A triazolam dose of less than 0.5 mg was administered to seven of eight subjects in the TRZPROG and five of eight subjects in the TRZ group, resulting in lower triazolam AUC values for the TRZPROG than for the TRZ group (p = 0.0275). There was clear evidence for a pharmacodynamic interaction. Mean effect ratios for all tests were greater in the TRZPROG group than in the TRZ group (DSST, p = 0.0097; continuous performance test, p = 0.0338; hand-eye coordination, p = 0.0041). The TRZPROG group had lower EC50 values than the TRZ group (DSST, p = 0.0435; continuous performance test, p = 0.0381; hand-eye coordination, p = 0.0154).(ABSTRACT TRUNCATED AT 250 WORDS)

Progesterone co-administration in patients discontinuing long-term benzodiazepine therapy: effects on withdrawal severity and taper outcome

Since recent research has suggested that the major metabolites of progesterone are barbiturate-like modulators of GABAergic function, we undertook a pilot study of the efficacy of micronized progesterone in attenuating withdrawal and facilitating discontinuation in benzodiazepine-dependent patients with a minimum of 1 year of continuous daily use. Forty-three patients taking a mean daily dose of 16.2 mg of diazepam (or its equivalent) were assigned, doubleblind, to treatment with either placebo (n = 13) or progesterone (n = 30). Progesterone was titrated to a mean daily dose of 1983 mg, and was co-administered for 3 weeks, after which the benzodiazepine was tapered by 25% per week. Progesterone (or placebo) was then continued for 4 weeks before being discontinued. There was no progesterone versus placebo difference in the severity of taper withdrawal. Withdrawal checklist change scores were 17.3 for progesterone and 16.5 for placebo (F 0.63; df 2.31; n.s.), and the Hamilton rating scale for anxiety change scores were 7.8 for progesterone and 6.3 for placebo (F 0.22; df 2.30; n.s.). There was no difference in ability to remain drug-free at 12 weeks post-taper, with 57% of progesterone-treated patients, and 58% of placebo-treated patients having a successful outcome.

Postmenopausal hormone replacement therapy--clinical implications

The menopause is defined as cessation of menstruation, ending the fertile period. The hormonal changes are a decrease in progesterone level, followed by a marked decrease in estrogen production. Symptoms associated with these hormonal changes may advocate for hormonal replacement therapy. This review is based on the English-language literature on the effect of estrogen therapy and estrogen plus progestin therapy on postmenopausal women. The advantages of hormone replacement therapy are regulation of dysfunctional uterine bleeding, relief of hot flushes, and prevention of atrophic changes in the urogenital tract. Women at risk of osteoporosis will benefit from hormone replacement therapy. The treatment should start as soon after menopause as possible and it is possible that it should be maintained for life. The treatment may be supplemented with extra calcium intake, vitamin D, and maybe calcitonin. Physical activity should be promoted, and cigarette smoking reduced if possible. Women at risk of cardiovascular disease will also benefit from hormone replacement therapy. There is overwhelming evidence that hormone therapy will protect against both coronary heart disease and stroke, and there is no increased risk of venous thrombosis or hypertension. A disadvantage of hormone replacement therapy is an increased risk of forming gall-bladder stones and undergoing cholecystectomy. Unopposed estrogen therapy gives a higher incidence of endometrial cancer in women with an intact uterus, but the contribution of progestins for about 10 days every month excludes this risk. Breast cancer in relation to estrogen-progestogen therapy has been given much concern, and the problem is still not fully solved. If there is a risk, it is small, and only after prolonged use of estrogen (15-20 years). The decision whether or not to use hormone replacement therapy should, of course, be taken by the individual woman in question, but her decision should be based on the available scientific information. It is the opinion of the authors that the advantages of hormone replacement therapy far exceed the disadvantages. We suggest that every woman showing any signs of hormone deprivation should be treated with hormone replacement therapy. This includes women with subjective or objective vaso-motor symptoms, genito-urinary symptoms, women at risk of osteoporosis (fast bone losers), and women at risk of cardiovascular diseases.

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

Doses of 100 mg of micronized progesterone (P) and of 0.5 mg of micronized estradiol (E2) were administered vaginally and orally, respectively, in the early follicular phase of the menstrual cycle in six premenopausal women. In the second cycle, the same doses were administered in the same subjects, orally for P and vaginally for E2. Serial blood samples were collected and the following steroids were assayed by highly reliable techniques: P, E2, estrone (E1), deoxycorticosterone (DOC), 5 alpha- and 5 beta-pregnanolone and the sulfates of E1, E2, and DOC. Circulating P and E2 levels were higher after vaginal than after oral administration, while those of E1 were similar after either route. Metabolites of P (DOC, DOCS and pregnanolone) were higher after oral administration. Concerning estrogen sulfates, E1S concentrations were similar whichever the route, while those of E2S were lower after oral than after vaginal administration. This study has confirmed that metabolism of ingested P and E2 occurs mainly in the intestine. Moreover, P was predominantly metabolized to 5 alpha-reduced derivatives, whatever the route of administration. In view of the metabolic pathways which are operative and of the peripheral plasma levels which were found, the vaginal route appears to be more adequate than the oral one for hormone replacement therapy.

Intranasal administration of estradiol in combination with progesterone to oophorectomized women: a pilot study

A pilot study was done to investigate the pharmacokinetics and acceptability of an intranasal 17 beta-estradiol/progesterone formulation. This formulation contained dimethyl-beta-cyclodextrin as a solubilizer and absorption enhancer of the steroid hormones. The study was performed in four oophorectomized and hysterectomized patients. After nasal delivery of 0.34 mg estradiol and 0.85 mg progesterone, concentration-time curves of progesterone, estradiol and its metabolite estrone were established. Rapid absorption of progesterone and estradiol was demonstrated. Progesterone peak-levels (3.9-6.7 nmol/l) exceeded the levels which are found in the follicular phase of the menstrual cycle, but did not reach the levels of the luteal phase. Comparison with an earlier reported study in which only estradiol was administered shows that the addition of progesterone does not alter the absorption and pharmacokinetics of estradiol. The nasal formulation was well accepted by the four patients and no adverse effects were noted.

Clinical and endometrial effects of oestradiol and progesterone in post-menopausal women

This study reports the clinical effects in a group of post-menopausal women after 4 months of treatment with 2 mg micronized 17 beta-oestradiol (E2) in combination with different doses of micronized progesterone (50, 100 or 200 mg) for 25 days each month. The 30 participants were divided into three groups. All of the subjects tolerated the preparation well and obtained relief from their climacteric complaints. None dropped out because of side effects and no changes were observed in blood pressure, weight or Papanicolaou cytology. Breakthrough bleeding was noted in the first cycle, mainly in the group receiving the lowest dose of progesterone. Endometrial biopsies performed before and after 4 months of treatment showed an atrophic endometrium in most of the women who received 100 mg progesterone and in all of the women on 200 mg progesterone. The results showed that this new combination of 2 mg E2 and micronized progesterone in different doses was both effective and well accepted.

Pharmacokinetics of oestrogens and progestogens

There are large inter- and intra-individual variations in the serum concentrations of natural and synthetic sex steroids irrespective of the route of administration. Oral ingestion of steroids has a stronger effect on hepatic metabolism than parenteral administration, as the local concentration in liver sinusoids are 4-5 times higher during the first liver passage. Oestradiol and oestrone are interconvertible, dependent on the local concentrations in liver and target organs, and oestrone sulphate serves as a large reservoir. The oestrone/oestradiol ratio has no physiological significance, as oestrone is only a weak oestrogen. Oestrone is both a precursor and a metabolite of oestradiol. Oestriol is extensively conjugated after oral administration. Therefore, the oestriol serum levels are similar after oral intake of 10 mg and after vaginal application of 0.5 mg oestriol resulting in similar systemic effectiveness. Conjugated oestrogens can easily enter the hepatocytes but are hormonally active only after hydrolyzation into the parent steroids. Ethinylestradiol which exerts strong effects on hepatic metabolism and inhibits metabolizing enzymes, should not be used for hormone replacement therapy. Among the progestogens, the progesterone derivatives have less effects on liver metabolism than the norethisterone derivatives (13-methyl-gonanes and 13-ethyl-gonanes). The highly potent 13-ethyl-gonanes are effective at very low doses, because of a slow inactivation and elimination rate due to the ethinyl group.

Sequential use of norethisterone and natural progesterone in pre-menopausal bleeding disorders

Sequential treatment with norethisterone (NET) or natural micronized progesterone (NMP) was administered randomly to 80 consecutive patients attending our clinic because of cycle disorders. The endometrial morphology indicated a need for progestogen therapy in all cases and the endometrium was hyperplastic in half of the women before therapy. Hyperplastic changes disappeared during the first three cycles of treatment with both NET and NMP, the duration of treatment being 6 months. However, the carry-over effect of both progestogens was short: three months after treatment was discontinued a proliferative or hyperplastic endometrial pattern recurred in 24% and 10% of cases, respectively. Whereas NET decreased oestradiol, follicle-stimulating hormone, luteinizing hormone and sex-hormone-binding globulin levels (P less than 0.001) no changes were seen during NMP treatment. High-density-lipoprotein cholesterol and triglyceride levels were also lowered by NET (P less than 0.001-0.02) and there was a slight decrease in phospholipids. NMP treatment induced no changes in serum lipid values and thus offers an alternative form of therapy in premenopausal bleeding disorders.

The aetiology of premenstrual syndrome is with the progesterone receptors

Recent work by molecular biologists into the behaviour of progesterone receptors (PR) has suggested an aetiological hypothesis for premenstrual syndrome (PMS). The proposition is that PMS is related to the transport by PR of sufficient progesterone (P) molecules into the cell nuclei during menstruating years. PR are widely distributed in target cells throughout the body (1, 2, 3, 4, 5, 6, 7). It suggests also why measuring P blood levels is of no value in PMS (8, 9, 10, 11); why pharmacological doses of P are required (8); and explains the failure of current double blind trials using low dose P (12, 13, 14, 15, 16).

Deoxycorticosterone secretion by the human ovary

Progesterone (P), deoxycorticosterone (DOC), estradiol-17 beta (E2) and cortisol (F) were determined simultaneously in the peripheral and the ovarian veins in 13 patients. Blood was collected either by direct sampling during laparotomy (12 patients) or by selective catheterization (1 patient). In all ovarian effluents P and E2 levels were significantly higher than in the peripheral vein. This was also true for DOC except in one ovarian effluent. The gradient was higher on the side of the corpus luteum-bearing ovary. P and E2 levels were correlated in ovarian as well as in peripheral veins. In ovarian effluents, DOC gradients were only significantly correlated with P levels (r = 0.63; P less than 0.01) suggesting a metabolic relationship between the two steroids.

Are estrogens indicated for the treatment of postmenopausal women?

A woman in the U.S. can now expect to live for 30 years or more past the menopause in a state of estrogen deprivation. Hypoestrogenic-associated conditions can be managed by a variety of medical regimens and lifestyle changes, but estrogen replacement therapy (ERT) is the most specific and universal treatment for all of the above conditions. Although concern for potential risks has limited its acceptance, the benefits of ERT extend beyond the amelioration of estrogen deprivation symptoms. Evidence is accumulating that ERT may offer protection from cardiovascular atherogenic disease. Several of the risks that have been associated with continuous ERT, such as endometrial cancer and breast cancer, are significantly reduced with the use of cyclic progestogens. Moreover, any concern arising from the use of conjugated estrogens and synthetic progestogens are being addressed by the recent introduction of orally active natural estrogen and soon, progesterone. With the demonstrated efficacy and safety of ERT, such therapy should be considered for all postmenopausal women.

Cyclic administration of an LHRH analogue and of progesterone in risk patients to oral contraceptives

Fifty-five cycles of 9 patients with normogonadotropic ovarian function having risks against oral contraceptives (OCs) and intrauterine devices (IUDs) were treated for contraception with buserelin in a dosage of 300 to 450 micrograms per day i.n. from day 5 to day 26 of the cycles. Additionally, progesterone (P) in a dosage of 75 mg per day was given by intravaginal suppositories from day 20 to day 26 of the cycle followed by a 7-day drug-free interval. Serum levels of LH, FSH and estradiol-17 beta (E2) showed a wide variability. However, most E2 levels were in the early or middle follicular phase range. Mean serum P levels monitored during P replacement were found to be in the secretory phase range. Pattern of menstrual cycles was regular in all patients except one whose menstrual bleedings were already disturbed prior to treatment. This mode of contraception was well accepted, no side effects were observed, no pregnancy occurred. In conclusion, contraception by low-dose intranasal application of buserelin combined with transvaginal P replacement seems to be a useful approach for contraception in patients at risk for both OCs and IUDs.

Radioimmunoassay of plasma progesterone after oral administration of micronized progesterone

A 200 mg dose of micronized progesterone (P) was administered orally to six healthy volunteers. Serial blood samples were collected and plasma P was assayed according to three methods of different specificity. The results were compared to those obtained with a reference technique based on gas chromatography-mass spectrometry. The interference of P metabolites particularly 5 alpha- and 5 beta-dihydroprogesterone was shown to be important when no or inadequate chromatography was included in the method. Radioimmunoassay after chromatography on a Celite column yielded results similar to those of the reference method. After oral administration, plasma P reached a peak at 3.00 +/- 0.44 h (mean +/- SEM; range: 1-4 h). The mean peak level 4.70 +/- 1.15 ng/ml (mean +/- SEM; range: 2.40-10.10 ng/ml) was at the lower limit of the range defined for a normal functional corpus luteum. The levels returned to initial values by 24 h after the single oral dose. The separation of P from its metabolites by an adequate chromatographic system appears mandatory after oral administration of micronized P.

Effects of progesterone, progestogens, and danazol on the specific cortisol binding in human plasma

The interaction of medroxyprogesterone acetate (MPA) with cortisol binding to corticosteroid-binding globulin (CBG) was studied with the use of an aqueous two-phase system with polyethylene glycol and dextran for equilibrium partition. Competitive binding analyses were also performed for progesterone (P), levonorgestrel, norethisterone, danazol, and tamoxifen. P and danazol were found to exert cortisol displacing activity, whereas MPA and the other tested compounds had no such effect. The glucocorticoid effects reported for MPA could not be explained by displacement. In general, P serum concentrations are lower than those of cortisol, and most binding sites on CBG are occupied by the glucocorticoid. At high P levels displacement and an increase in free cortisol may occur. Danazol displacement of cortisol is hampered by its pronounced albumin binding. In conclusion, none of the tested compounds should increase free and biologically active cortisol during normal clinical treatment.

Subfractions of high-density lipoprotein cholesterol during estrogen replacement therapy: a comparison between progestogens and natural progesterone

Subfractions of high-density lipoprotein cholesterol and its apolipoproteins were followed up in 58 postmenopausal women during three cycles of unopposed estrogen replacement therapy with 2 mg of estradiol valerate daily. During the last 10 days of the following three cycles the women received sequential addition of either 250 micrograms of levonorgestrel, 10 mg of medroxyprogesterone acetate, or 200 mg of natural micronized progesterone. Both progestogens significantly decreased total high-density lipoprotein cholesterol as well as subfraction 2 of high-density lipoprotein. Data suggest that doses and relative biologic activity of 19-norsteroids and 17-hydroxyprogesterone derivatives are more important for their metabolic effects than are qualitative differences. Natural progesterone had no apparent influence on high-density lipoprotein cholesterol or its subfractions and may develop into an attractive alternative to synthetic progestogens.