Efficacy and acceptability of intranasal 17 beta-oestradiol for menopausal symptoms: randomised dose-response study. Aerodiol Study Group

Intranasal drug delivery: opportunities and toxicologic challenges during drug development

Over the past 10 years, the interest in intranasal drug delivery in pharmaceutical R&D has increased. This review article summarises information on intranasal administration for local and systemic delivery, as well as for CNS indications. Nasal delivery offers many advantages over standard systemic delivery systems, such as its non-invasive character, a fast onset of action and in many cases reduced side effects due to a more targeted delivery. There are still formulation limitations and toxicological aspects to be optimised. Intranasal drug delivery in the field of drug development is an interesting delivery route for the treatment of neurological disorders. Systemic approaches often fail to efficiently supply the CNS with drugs. This review paper describes the anatomical, histological and physiological basis and summarises currently approved drugs for administration via intranasal delivery. Further, the review focuses on toxicological considerations of intranasally applied compounds and discusses formulation aspects that need to be considered for drug development.

Intranasal 17β-Estradiol Modulates Spatial Learning and Memory in a Rat Model of Surgical Menopause

Exogenously administered 17β-estradiol (E2) can improve spatial learning and memory, although E2 also exerts undesired effects on peripheral organs. Clinically, E2 has been solubilized in cyclodextrin for intranasal administration, which enhances brain-specific delivery. Prior work shows that the cyclodextrin structure impacts region-specific brain distribution of intranasally administered small molecules. Here, we investigated (1) cyclodextrin type-specific modulation of intranasal E2 brain distribution, and (2) cognitive and peripheral tissue effects of intranasal E2 in middle-aged ovariectomized rats. First, brain and peripheral organ distribution of intranasally administered, tritiated E2 was measured for E2 solubilized freely or in one of four cyclodextrin formulations. The E2-cyclodextrin formulation with greatest E2 uptake in cognitive brain regions versus uterine horns was then compared to free E2 on learning, memory, and uterine measures. Free E2 improved spatial reference memory, whereas E2-cyclodextrin impaired spatial working memory compared to their respective controls. Both E2 formulations increased uterine horn weights relative to controls, with E2-cyclodextrin resulting in the greatest uterine horn weight, suggesting increased uterine stimulation. Thus, intranasal administration of freely solubilized E2 is a strategic delivery tool that can yield a cognitively beneficial impact of the hormone alongside decreased peripheral effects compared to intranasal administration of cyclodextrin solubilized E2.

Variation in menopausal vasomotor symptoms outcomes in clinical trials: a systematic review

BACKGROUND

There is substantial variation in how menopausal vasomotor symptoms are reported and measured among intervention studies. This has prevented meaningful comparisons between treatments and limited data synthesis.

OBJECTIVES

To review systematically the outcome reporting and measures used to assess menopausal vasomotor symptoms from randomised controlled trials of treatments.

SEARCH STRATEGY

We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials from inception to May 2018.

SELECTION CRITERIA

Randomised controlled trials with a primary outcome of menopausal vasomotor symptoms in women and a sample size of at least 20 women per study arm.

DATA COLLECTION AND ANALYSIS

Data about study characteristics, primary vasomotor-related outcomes and methods of measuring them.

MAIN RESULTS

The search identified 5591 studies, 214 of which were included. Forty-nine different primary reported outcomes were identified for vasomotor symptoms and 16 different tools had been used to measure these outcomes. The most commonly reported outcomes were frequency (97/214), severity (116/214), and intensity (28/114) of vasomotor symptoms or a composite of these outcomes (68/214). There was little consistency in how the frequency and severity/intensity of vasomotor symptoms were defined.

CONCLUSIONS

There is substantial variation in how menopausal vasomotor symptoms have been reported and measured in treatment trials. Future studies should include standardised outcome measures which reflect the priorities of patients, clinicians, and researchers. This is most effectively achieved through the development of a Core Outcome Set. This systematic review is the first step towards development of a Core Outcome Set for menopausal vasomotor symptoms.

TWEETABLE SUMMARY

Menopausal hot flushes and night sweats have been reported in 49 different ways in clinical research. A core outcome set is urgently required.

Engineering poly(lactic-co-glycolic acid) (PLGA) micro- and nano-carriers for Controlled Delivery of 17β-Estradiol

With menopause, circulating levels of 17β-estradiol (E2) markedly decrease. E2-based hormone therapy is prescribed to alleviate symptoms associated with menopause. E2 is also recognized for its beneficial effects in the central nervous system (CNS), such as enhanced cognitive function following abrupt hormonal loss associated with ovariectomy. For women with an intact uterus, an opposing progestogen component is required to decrease the risk of developing endometrial hyperplasia. While adding an opposing progestogen attenuates these detrimental effects on the uterus, it can attenuate the beneficial effects of E2 in the CNS. Poly(lactic-co-glycolic acid) (PLGA) micro- and nano- carriers (MNCs) have been heavily investigated for their ability to enhance the therapeutic activity of hydrophobic agents following exogenous administration, including E2. Multiple PLGA MNC formulation parameters, such as composition, molecular weight, and type of solvent used, can be altered to systematically manipulate the pharmacokinetic and pharmacodynamic profiles of encapsulated agents. Thus, there is an opportunity to enhance the therapeutic activity of E2 in the CNS through controlled delivery from PLGA MNCs. The aim of this review is to consider the fate of exogenously administered E2 and discuss how PLGA MNCs and route of administration can be used as strategies for controlled E2 delivery.

Nasal drug delivery: Design of a novel mucoadhesive and in situ gelling polymer

The aim of the present study was to establish a novel polymeric excipient for liquid nasal dosage forms exhibiting viscosity increasing properties, improved mucoadhesion and stability towards oxidation in solution. In order to achieve this goal, 2-mercaptonicotinic acid was first coupled to l-cysteine by disulfide exchange reaction and after purification directly attached to the polymeric backbone of xanthan gum by carbodiimide mediated amide bond formation. The resulting conjugate was characterized with respect to the amount of coupled ligand, the in situ gelling behavior, mucoadhesive properties and stability towards oxidation. Furthermore, the influence of preactivated polymers on ciliary beat frequency (CBF) of porcine nasal epithelial cells was investigated. Results showed, that 252.52±20.54μmol of the ligand was attached per gram polymer. No free thiol groups could be detected on the polymeric backbone indicating entire preactivation. Rheological investigations of polymer mucus mixtures revealed a 1.7-fold and 2.5-fold enhanced mucoadhesion of entirely preactivated xanthan (Xan-Cys-MNA) compared to thiolated xanthan (Xan-Cys) and unmodified xanthan (Xan). Tensile force evaluation reported a 2.87 and 5.11-fold higher total work of adhesion (TWA) as well as a 1.63 and 2.41-fold higher maximum detachement force of Xan-Cys-MNA compared to Xan-Cys and Xan. In the presence of H₂O₂ as an oxidizing agent Xan-Cys-MNA showed unlike Xan-Cys no increase in viscosity, indicating high stability towards oxidation. Addition of CaCl₂ to Xan-Cys-MNA solutions caused a decrease in viscosity at nevertheless higher total viscosity. Results from CBF studies proved nasal safety for the novel conjugate. According to these results, entirely preactivated thiolated xanthan gum seems to be a promising excipient for nasal dosage forms in order to improve drug bioavailability.

Bioidentical hormones for women with vasomotor symptoms

BACKGROUND

Various hormone therapies (HT) are available to treat menopausal vasomotor symptoms. Bioidentical hormones are chemically identical to those produced by the human body, and several types are well-tested and available on prescription. Many women have opted for bioidentical hormone therapy (BHT) on the assumption that it is safer than other forms of HT. We evaluated the evidence.

OBJECTIVES

To determine the effectiveness and safety of bioidentical hormones compared to placebo or non-bioidentical hormones for the relief of vasomotor symptoms.

SEARCH METHODS

In July 2015 we searched the Cochrane Central Register of Controlled Trials, PubMed, Embase, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), registers of ongoing trials and the reference lists of articles retrieved.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing bioidentical hormone therapy (BHT) versus placebo or non-bioidentical hormones.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration. Our primary outcome was vasomotor symptoms (hot flushes and night sweats). We evaluated the overall quality of the evidence using Grading of Recommendations Assessment, Development and Evaluation criteria (GRADE).

MAIN RESULTS

We included 23 RCTs (5779 participants). Most studies (20/23) included only women with moderate to severe hot flushes. All studies compared unopposed 17 beta-estradiol (beta-estradiol) versus placebo or conjugated equine estrogens (CEE). None of the studies reported night sweats as a separate outcome. BHT patch versus placebo Frequency of hot flushesFour RCTs reported data suitable for analysis. There were fewer hot flushes in the BHT group, with a moderate to large effect size (SMD -0.68, 95% CI -0.83 to -0.53, four RCTs, 793 women, I(2) = 67%, low quality evidence). There was moderate heterogeneity, but a consistent direction of effect. Seven RCTs reported data unsuitable for analysis; all reported a benefit in the intervention group. Symptom intensityTwo RCTs reported analysable data. Measured on a 0-100 visual analogue scale (VAS), hot flush intensity was lower in the BHT group (MD -19.94 points, 95% CI -24.86 to -15.02, two RCTs, 393 women, I(2) = 54%, low quality evidence). There was moderate heterogeneity, but a consistent direction of effect. Adverse effectsAdverse events (such as headache, vaginal bleeding, breast tenderness and skin reactions) were more common in the intervention group (odds ratio (OR) 2.14, 95% CI 1.29 to 3.54, 9 RCTs, 1822 women, I(2) = 73%, low quality evidence). There was moderate heterogeneity, but a consistent direction of effect. In one study, five women in the intervention group developed endometrial hyperplasia. BHT gel versus placebo Hot flush frequencyThree RCTs reported this outcome, but the data were unsuitable for analysis. All reported a benefit in the BHT group. Adverse effectsAdverse events were more common in the BHT group (OR 1.41, 95% CI 1.09 to 1.83, 3 RCTs, 1086 women, I(2) = 0%, moderate quality evidence). Oral BHT versus placebo Hot flush frequencyTwo studies reported analysable data. There were fewer hot flushes in the BHT group, with a moderate to large effect size (SMD -0.80, 95% CI -1.03 to -0.57, two RCTs, 356 women, I(2) = 14%, low quality evidence). Adverse effectsThere was no evidence of a difference between the groups (OR 1.28, 95% CI 0.84 to 1.96, 3 RCTs, 433 women, I(2) = 0%, low quality evidence). Topical BHT emulsion versus placebo Hot flush frequencyOne study with data unsuitable for analysis reported a benefit in the intervention group. Adverse effectsThere was no evidence of a difference between the groups (OR 1.46, 95% CI 0.80 to 2.66, one RCT, 200 women, low quality evidence). Intranasal BHT versus placebo Hot flush frequencyOnly one study reported analysable data. There were fewer hot flushes per day in the BHT group (MD -3.04 95% CI -4.05 to -2.03, one study, 458 women, moderate quality evidence) Adverse effectsAdverse events (such as headache, breast tenderness, arthralgia and nausea) were more common in the intervention group (OR 1.96, 95% CI 1.26 to 3.03, one RCT, 458 women, moderate quality evidence). Subgroup analysesSubgroup analyses by dose of BHT suggested that higher doses of BHT may be associated with more effectiveness but also higher risk of adverse effects. BHT patch versus 0.625 mg CEETwo RCTs reported this comparison, but the data were unsuitable for analysis. Hot flush frequencyBoth RCTs reported no evidence of a difference between the groups. Adverse effectsFindings were inconsistent. In one comparison (0.1 mg BHT versus CEE), breast pain and vaginal bleeding were more frequent in the BHT group. Oral BHT versus 0.625 mg CEE Hot flush frequencyOne study with data unsuitable for analysis reported no evidence of a difference between the groups. Adverse effectsThere was no evidence of a difference between the groups (OR 1.20, 95% CI 0.50 to 2.87, one RCT, 103 women, very low quality evidence).

AUTHORS' CONCLUSIONS

There was low to moderate quality evidence that BHT in various forms and doses is more effective than placebo for treating moderate to severe menopausal hot flushes. There was low to moderate quality evidence of higher rates of adverse effects such as headache, vaginal bleeding, breast tenderness and skin reactions in the BHT group. There was some evidence to suggest that higher doses of BHT are associated with greater effectiveness but also with higher risk of adverse effects. Although all the included studies used unopposed estrogen, it is recommended best practice to use progestogen therapy in women with a uterus taking estrogen in order to avoid endometrial hyperplasia, regardless of the source of the estrogen. No data are yet available about the safety of BHT with regard to long-term outcomes such as heart attack, stroke and breast cancer.There was no good evidence of a difference in effectiveness between BHT and CEE, and findings with regard to adverse effects were inconsistent. The quality of the evidence was too low to reach any firm conclusions.The main limitations in the quality of the evidence were study risk of bias (mainly due to poor reporting of methods), imprecision and lack of data suitable for analysis.

Quantitative efficacy of soy isoflavones on menopausal hot flashes

AIM

This study aimed to quantitate the efficacy of soy isoflavones in the treatment of menopausal hot flashes.

METHODS

Model based meta-analysis (MBMA) was used to quantitate the efficacy of soy isoflavones. We conducted a systemic literature search to build a time-effect model for placebo and soy isoflavones in treating menopausal hot flashes. Studies were identified, subjected to inclusion and exclusion criteria, and reviewed.

RESULTS

From 55 articles, 16 studies of soy isoflavones met the inclusion criteria, and contained 65 and 66 mean effect values in placebo and soy isoflavone groups, respectively, from about 1710 subjects. Interestingly, the developed model was found to describe adequately the time course of hot flashes reduction after administration of placebo and soy isoflavones. Using this model, we found that the maximal percentage change of hot flashes reduction by soy isoflavones was 25.2% after elimination of the placebo effect, accounting for 57% of the maximum effects of estradiol (Emax-estradiol  = 44.9%). However, a time interval of 13.4 weeks was needed for soy isoflavones to achieve half of its maximal effects, much longer than estradiol, which only required 3.09 weeks. These results suggest that treatment intervals of 12 weeks are too short for soy isoflavones, which require at least 48 weeks to achieve 80% of their maximum effects.

CONCLUSIONS

Soy isoflavones show slight and slow effects in attenuating menopausal hot flashes compared with estradiol.

Female resistance to pneumonia identifies lung macrophage nitric oxide synthase-3 as a therapeutic target

To identify new approaches to enhance innate immunity to bacterial pneumonia, we investigated the natural experiment of gender differences in resistance to infections. Female and estrogen-treated male mice show greater resistance to pneumococcal pneumonia, seen as greater bacterial clearance, diminished lung inflammation, and better survival. In vitro, lung macrophages from female mice and humans show better killing of ingested bacteria. Inhibitors and genetically altered mice identify a critical role for estrogen-mediated activation of lung macrophage nitric oxide synthase-3 (NOS3). Epidemiologic data show decreased hospitalization for pneumonia in women receiving estrogen or statins (known to activate NOS3). Pharmacologic targeting of NOS3 with statins or another small-molecule compound (AVE3085) enhanced macrophage bacterial killing, improved bacterial clearance, and increased host survival in both primary and secondary (post-influenza) pneumonia. The data identify a novel mechanism for host defense via NOS3 and suggest a potential therapeutic strategy to reduce secondary bacterial pneumonia after influenza.

Pharmacokinetics and Acute Safety of Inhaled Testosterone in Postmenopausal Women

This was a preliminary feasibility study to assess the pharmacokinetics and acute safety of a single dose of orally inhaled testosterone via the AERx system, a novel handheld aerosol delivery system in postmenopausal women. Twelve postmenopausal women stabilized on oral estrogen therapy were treated with a single dose of testosterone (0.1, 0.2, or 0.3 mg) by inhalation. Plasma concentrations of sex steroids were measured between 1 and 360 minutes. Pulmonary and cardiovascular adverse events were monitored. Inhaled testosterone produced a dose-dependent increase in plasma total and free testosterone. At the highest dose (0.3 mg), total and free testosterone increased from baseline (mean +/- SD, 0.6 +/- 0.3 nmol/L, 2.5 +/- 1.0 pmol/L) to maximum levels of 62.6 +/- 20.4 nmol/L (total) and 168.2 +/- 50.2 pmol/L(free), occurring 1 to 2 minutes after dosing. A 2-compartment model best described the free and total testosterone pharmacokinetic profile. Dihydrotestosterone levels were higher than baseline at 60 minutes (P < .0002). Estradiol did not vary, but sex hormone binding globulin and albumin fell. There were no adverse events related to the treatment. Administration of inhaled testosterone is safe and achieves a supraphysiologic "pulse" kinetic profile of total and free testosterone with a rapid return to pretreatment levels.

Breast density changes associated with postmenopausal hormone therapy: post hoc radiologist- and computer-based analyses

OBJECTIVE

The aim of this study was to assess the impact of oral hormone therapy (HT) on breast density in postmenopausal women and to compare the use of computer-based automated approaches for the assessment of breast density with reference to traditional methods.

METHODS

Low-dose oral estrogen (1 mg) continuously combined with drospirenone (2 mg) was administered to postmenopausal women for up to 2 years (26 treatment cycles, 28 d/cycle) in a randomized, placebo-controlled trial. This post hoc analysis assessed the changes in breast density measured from digitized images by two radiologist-based approaches (Breast Imaging Reporting and Data System score and interactive threshold) and one computer-based technique (heterogeneity examination of radiographs). Correlations of temporal changes in breast density with changes in serum estradiol levels, biochemical markers of bone metabolism, and bone mineral density at the spine and femur were also assessed.

RESULTS

Breast density assessed by the radiologist-based approaches increased significantly from baseline in the HT group (P < 0.01), with significant divergence from placebo at 2 years (P < 0.01). Heterogeneity examination of radiograph score by computer-based technique was unchanged in the HT group and decreased significantly with placebo (P < 0.001) to produce a significant group divergence (P < 0.05). Changes in mammographic markers by radiologist- and computer-based approaches correlated with each other in the HT group (P < 0.01) but not in the placebo group.

CONCLUSIONS

HT for 2 years in postmenopausal women significantly increased radiologist-assessed breast density compared with placebo, in addition to significant changes in estrogen levels, markers of bone metabolism, and bone mineral density. Computer-automated techniques may be comparable with and offer advantages over traditional methods.

The role of intranasal estradiol spray in the management of moderate to severe vasomotor symptoms in menopausal women

Hormone therapy (HT) is the most effective treatment at present available for climacteric symptoms. As harmful effects were highlighted in recent randomized clinical trials, the risk-benefit ratio does not favor the use of HT for prevention of cardiovascular diseases and bone fractures in postmenopausal women. Nevertheless, experimental and clinical trials suggest that adverse effects of HT basically depend on the estrogen and progestin formulation, dosage, route of administration, patient's age, associated diseases, and duration of treatment. All estrogen formulations and routes of administration have comparable beneficial effects on vasomotor and urogenital symptoms and on bone structure. But adverse effects may differ. Thus, cardiovascular and invasive breast cancer risks are higher with oral estrogen than with transdermal estradiol. However, transdermal estradiol is not free of inconveniences such as differences among individuals in absorption rates, loss of patches due to poor adhesion, and skin irritation. HT requires careful adjustment to each individual patient and continuous monitoring of clinical evolution. In the future, this adjustment and maybe the use of alternative routes such as intranasal could benefit from genetic screening to maximize in each individual the ratio between positive and adverse effects of HT.

New hormonal therapies and regimens in the postmenopause: routes of administration and timing of initiation

Since the publication of the Women's Health Initiative (WHI) study followed by the results of the Million Women Study (MWS), the role of hormonal therapy in postmenopausal women has been further challenged. The risks attributed to hormone therapy have been overestimated and the data has been wrongly extrapolated to the whole class of therapies. The trends in postmenopausal hormonal therapy seem now to favor the non-oral delivery routes for both the estrogen and the progestin for women with an intact uterus, based on the assumption that a lesser stimulation of the liver proteins and a neutral metabolic profile would be more favorable in terms of cardiovascular and venous risk. The combination of non-oral administration of estradiol and local delivery of progesterone or a progestin such as levonorgestrel by means of gels, sprays, vaginal rings or intrauterine systems would represent new methods of replacement therapy for the menopausal woman, improving compliance and minimizing the risks of hormone replacement. Several of these systems are either available or in development. Long-term studies on the risk/benefit of various non-oral formulations are certainly warranted.

Postnatal estradiol up-regulates lung nitric oxide synthases and improves lung function in bronchopulmonary dysplasia

RATIONALE

Nitric oxide (NO) plays an important role in lung development and perinatal lung function, and pulmonary NO synthases (NOS) are decreased in bronchopulmonary dysplasia (BPD) following preterm birth. Fetal estradiol levels increase during late gestation and estradiol up-regulates NOS, suggesting that after preterm birth estradiol deprivation causes attenuated lung NOS resulting in impaired pulmonary function.

OBJECTIVE

To test the effects of postnatal estradiol administration in a primate model of BPD over 14 days after delivery at 125 days of gestation (term = 185 d).

METHODS

Cardiopulmonary function was assessed by echocardiography and whole body plethysmography. Lung morphometric and histopathologic analyses were performed, and NOS enzymatic activity and abundance were measured.

MEASUREMENTS AND MAIN RESULTS

Estradiol caused an increase in blood pressure and ductus arteriosus closure. Expiratory resistance and lung compliance were also improved, and this occurred before spontaneous ductal closure. Furthermore, both oxygenation and ventilation indices were improved with estradiol, and the changes in lung function and ventilatory support requirements persisted throughout the study period. Whereas estradiol had negligible effect on indicators of lung inflammation and on lung structure assessed after the initial 14 days of ventilatory support, it caused an increase in lung neuronal and endothelial NOS enzymatic activity.

CONCLUSIONS

In a primate model of BPD, postnatal estradiol treatment had favorable cardiovascular impact, enhanced pulmonary function, and lowered requirements for ventilatory support in association with an up-regulation of lung NOS. Estradiol may be an efficacious postnatal therapy to improve lung function and outcome in preterm infants.

Differing transcriptional responses to pulsed or continuous estradiol exposure in human umbilical vein endothelial cells

This study used human umbilical vein endothelial cells (HUVECs) that were treated with 17beta-estradiol for 5 days as 1h pulse or 24h continuous treatment at concentrations such that the 24h exposure (concentration x time) was identical in both conditions. Cell proliferation was studied and gene expression profiling was carried out using the Affymetrix GeneChip microarray analysis. Changes in morphology and apoptosis in HUVECs were examined with electron microscopy. Time-course studies of expression of genes vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) were performed by quantitative PCR. We observed that cell proliferation was significantly decreased over days 3-5 with pulsed estradiol treatment relative to constant exposure. Microarray results showed that after 5 days, 801 genes differed (P<0.05) between continuous versus pulsed estradiol treatment. Functional analysis showed a significant number of genes to be associated with apoptosis and cell cycle pathways. We did not find any evidence of apoptosis from flow cytometry or electron microscopy examination. Our study highlights a large number of significantly different molecular responses to estradiol depending upon the mode of administration of estradiol. Significant changes were observed in genes involved in apoptosis and proliferation including VEGF, IGF receptors, and tumor protein p53.

Intranasal delivery: physicochemical and therapeutic aspects

Interest in intranasal (IN) administration as a non-invasive route for drug delivery continues to grow rapidly. The nasal mucosa offers numerous benefits as a target issue for drug delivery, such as a large surface area for delivery, rapid drug onset, potential for central nervous system delivery, and no first-pass metabolism. A wide variety of therapeutic compounds can be delivered IN, including relatively large molecules such as peptides and proteins, particularly in the presence of permeation enhancers. The current review provides an in-depth discussion of therapeutic aspects of IN delivery including consideration of the intended indication, regimen, and patient population, as well as physicochemical properties of the drug itself. Case examples are provided to illustrate the utility of IN dosing. It is anticipated that the present review will prove useful for formulation scientists considering IN delivery as a delivery route.

Effects of intranasal versus oral hormone therapy on asymmetric dimethylarginine in healthy postmenopausal women: a randomized study

OBJECTIVE

Oral estrogens reduce asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, and an independent risk factor for cardiovascular disease. This study was conducted to compare the effect on ADMA between intranasal and oral 17beta-estradiol (E2) combined with norethisterone (acetate) (NET(A)) administration in postmenopausal women.

METHODS

In a two-center, randomized, double-blind, comparative study 90 healthy postmenopausal women (age 56.6+/-4.7 years) received daily continuous combined intranasal E2/NET 175 microg/275 microg (n=47) or oral E2/NETA 1 mg/0.5 mg (n=43) for one year. At baseline, week 12 and 52, plasma concentrations of ADMA, arginine and symmetric dimethylarginine (SDMA) were measured by high-performance liquid chromatography.

RESULTS

Oral E2/NETA reduced ADMA concentrations (-7.4%; 95% confidence interval (CI) -10.4 to -4.4%), while intranasal E2/NET had no effect (-0.8%; 95% CI -3.7 to 2.1%) after 52 weeks. In both groups, arginine was transiently decreased compared to baseline at week 12 (intranasal: -6.1%; 95% CI -9.1 to -3.0%; oral: -6.5%; 95% CI -10.9 to -2.1%). Only oral E2/NETA reduced SDMA concentrations.

CONCLUSIONS

Oral administration of E2/NETA reduced ADMA and SDMA concentrations, whereas intranasal administration did not. Both treatments transiently reduced arginine. The decrease in ADMA by oral estrogens could be a key phenomenon in the modulation of nitric oxide synthesis by postmenopausal hormone therapy.

Effects of intranasal 17β-estradiol administration on serum bioactive interleukin-6 and C-reactive protein levels in healthy postmenopausal women

OBJECTIVE

Oral estrogen increases the levels of C-reactive protein (CRP), which is an independent risk factor for coronary heart disease in healthy individuals. The aim of our study was to investigate the effects of intranasal 17beta-estradiol (E2) on serum CRP and its most potent stimulant, interleukin-6 in healthy postmenopausal women.

DESIGN

Thirty-six healthy postmenopausal women (45-54 y) were enrolled. According to their individual preferences, they were assigned to intranasal (n = 10), transdermal (n = 14), or oral (n = 12) continuous E2 treatment with a sequential progestin (10-14 d in a 28-d cycle). Blood samples were drawn at baseline and after 3, 6, and 12 months during the estrogen-only phase to adjust for the progestin effect.

RESULTS

In women taking intranasal or transdermal E2, there were no significant changes in median serum CRP levels during the 12-month treatment period. In women taking oral E2 preparations, serum median CRP levels were significantly higher compared to baseline after 6 and 12 months of the therapy (P < 0.05). Conversely, serum median bioactive interleukin-6 levels were significantly lower after 6 and 12 months in women taking E2 intranasally or orally and after 12 months in women taking E2 transdermally (P < 0.05).

CONCLUSIONS

The results of our study show that intranasal, similarly to transdermal, E2 administration does not increase serum CRP levels in postmenopausal women. They also support the hypothesis that CRP increase during oral estrogen treatment is not mediated by the enhancement of interleukin-6 production by the immune cells but is rather caused by the hepatic first-pass metabolism effect.

Drug delivery systems for hormone therapy

Various types of formulations and delivery devices have been developed for hormone therapy (HT) and their modes of hormone action and patient responses have been evaluated. Although the Women's Health Initiative (WHI) reported the controversial results on estrogen/progestin combination therapy, HT still remains a primary therapeutic option for the treatment of menopausal symptoms and osteoporosis. As a novel alternative to HT may not be probable in clinical use for the next decade, the currently available formulations containing estrogen and progestogen should be properly optimized for HT. The extensive reviews and comparisons on the characteristics of various types of HT could lead to the development of an efficient delivery formulation which maximizes patient compliance and minimizes adverse effects for individual users.

Intranasal continuous combined 17β-estradiol/norethisterone therapy improves the lipid profile in healthy postmenopausal women

OBJECTIVE

To compare the effects of continuous combined 17beta-estradiol (E2) plus norethisterone (acetate) [NET(A)] therapy by either intranasal or oral administration on the lipid profile in postmenopausal women.

DESIGN

Randomized, double-blind, multicenter trial.

SETTING

Gynecologic outpatient department.

PATIENT(S)

Two-hundred thirty-three healthy postmenopausal women.

INTERVENTION(S)

Women received continuous combined hormone therapy, either intranasal E2/NET (175 microg/275 microg) as a spray (n = 117) or oral E2/NETA (1 mg/0.5 mg) as a capsule (n = 116), for 1 year.

MAIN OUTCOME MEASURE(S)

Fasting plasma concentrations of lipids and (apo)lipoproteins; and atherogenic indices at baseline and after 12, 24, and 52 weeks of treatment.

RESULT(S)

We found a significant (P < .001) decrease from baseline in both treatment groups in total, low-density lipoprotein- (LDL), high-density lipoprotein- (HDL), and HDL2-cholesterol, in triglycerides, apolipoprotein B (apoB), and lipoprotein(a). Levels of HDL3-cholesterol and apolipoprotein A1 (apoA1) were transiently decreased in the intranasal group. In the oral group, compared with the intranasal group, the decrease was larger for ratio total and LDL-cholesterol and lipoprotein(a) and smaller for triglycerides and apoA1. In the oral group, the ratios total/HDL cholesterol and LDL/HDL cholesterol were lowered, and the ratio apoB/LDL was increased, more than in the intranasal group.

CONCLUSION(S)

Both intranasal and oral E2/NET(A) therapy improved the lipid profile of healthy postmenopausal women, with some effects being more pronounced after oral administration.

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.

Intranasal 17β-estradiol treatment and Vitamin B12, folate and homocysteine in menopause

OBJECTIVE

This study assessed the effect of intranasal administration of 17beta-estradiol (Aerodiol) on plasma levels of homocysteine, Vitamin B12 and folate in postmenopausal women.

METHODS

In all, 26 symptomatic postmenopausal women who had undergone hysterectomy and oophorectomy at least 12 months previously participated in this 6-month randomized prospective clinical study. Menopause was determined by serum FSH level >30 microIU/ml and serum estradiol concentration <30 pg/ml. Intranasal 17beta-estradiol treatment was given once daily at a standard daily dose of 300 microg to 16 women, and 10 did not receive any treatment.

RESULTS

In the group receiving intranasal 17beta-estradiol, mean (+/-S.D.) plasma homocysteine level decreased significantly from pre-treatment values (from 16.68+/-4.33 to 14.15+/-1.18 nmol/ml, p=0.029) and the mean folate level increased (from 4.11+/-0.80 to 5.64+/-1.87 ng/ml, p=0.012). Vitamin B12 levels showed a tendency towards increasing. In the treated group, significant negative correlations were observed between homocysteine and folate values (r=-0.586, p=0.017) and between homocysteine and Vitamin B12 values (r=-0.672, p=0.004). No significant changes were observed in the untreated group.

CONCLUSION

The reduction in plasma homocysteine levels observed after 6 months' treatment with intranasal 17beta-estradiol may reflect an alteration in folate and Vitamin B12 homeostasis.

Spotlight on estradiol-intranasal in the management of menopause

Estradiol-intranasal is a nasal spray formulation containing an aqueous solution of 17beta-estradiol that has a unique pulse-like pharmacokinetic profile. In a well designed, placebo-controlled trial estradiol-intranasal 200 to 400 microg/day significantly reduced the incidence and severity of climacteric symptoms in women with moderate to severe menopausal symptoms after 4 and 12 weeks' treatment. The efficacy of estradiol-intranasal 300 microg/day was similar to that of oral estradiol 2 mg/day in this and another double-blind placebo-controlled trial. This equivalent efficacy was maintained in a subgroup of women with initially severe symptoms, and in smokers. Reductions in the incidence of atrophic vaginal mucosa and genitourinary symptoms and increases in the karyopyknotic index achieved with estradiol-intranasal 300 microg/day were also similar to those observed with oral estradiol 2 mg/day. Assessments of the effects of estradiol-intranasal on the complications of menopause (increased risk of cardiovascular disease and osteoporosis) are ongoing; however, estradiol-intranasal (sequentially combined with a progestogen) produced significant beneficial effects on some lipid parameters and on markers of bone resorption and formation, and bone mineral density in postmenopausal women. Estradiol-intranasal had no significant effects on serum levels of most of the assessed hemostatic factors, or on angiotensinogen or insulin levels. Estradiol-intranasal 100 to 600 microg/day was generally well tolerated in clinical trials and most adverse events were mild to moderate. The most commonly reported events were nasal symptoms and mastalgia. There was no evidence of endometrial hyperplasia with up to 1 year's treatment with estradiol-intranasal 300 microg/day combined with a progestogen. The incidence of mastalgia and withdrawal or breakthrough bleeding was lower with estradiol-intranasal 300 microg/day than with oral estradiol 2 mg/day (both administered with a progestogen) in one trial. In another trial, the incidence of mastalgia was lower with estradiol-intranasal 300 microg/day than with estradiol transdermal 50microg (both administered with a progestogen). However, the overall incidence of adverse events was similar between the two treatments in this trial. In conclusion, estradiol-intranasal 200 to 400 microg/day (optimal initiating dose 300 microg/day) reduces the incidence and severity of menopausal climacteric symptoms and has a good tolerability profile. Thus, evidence to date suggests that estradiol-intranasal is a useful treatment option for menopausal symptoms.

Pulsed estradiol exposure has a limited ability to induce uterine proliferation in ovariectomised female Wistar rats

All post-menopausal hormone replacement therapies (HRT) aim to provide a steady mid-follicular serum concentration of estrogen, with the exception of pulsed estrogen therapy, which concentrates estradiol (E2) exposure in the few hours following administration. This study was carried out to identify and characterise cellular and molecular mechanisms specifically involved in the response of the uterus to pulsed E2. Ovariectomised Wistar rats were treated with E2 for 10 days via IV route to mimic pulsed therapy (1, 4, 10 and 250 microg/kg) or with a subcutaneous pump to mimic standard HRT (10 and 250 microg/kg). Pulsed estrogen therapy effects on uterus was revealed by general E2 sensitivity markers (C3 mRNA, progesterone receptor (PR)) from the lower dose with no over stimulation even at the highest dose conversely to what observed with continuous exposure. Uterotrophic effect of pulsed E2 (uterine weight and epithelium thickness) was observed at all dose administered but with a limited maximal effect comparable to the ranges measurable in sham animals. This data corroborates with proliferating cell nuclear antigen (PCNA) expression in the uterine epithelium used as a marker of proliferation. PCNA was significantly induced after continuous administration but only slightly after pulsed E2 (250 microg/kg). In summary, pulsed E2 leads to a more limited proliferative effect than with continuous E2 in the uterus.

Cyclodextrin-based pharmaceutics: past, present and future

Cyclodextrins are cyclic oligomers of glucose that can form water-soluble inclusion complexes with small molecules and portions of large compounds. These biocompatible, cyclic oligosaccharides do not elicit immune responses and have low toxicities in animals and humans. Cyclodextrins are used in pharmaceutical applications for numerous purposes, including improving the bioavailability of drugs. Current cyclodextrin-based therapeutics are described and possible future applications discussed. Cyclodextrin-containing polymers are reviewed and their use in drug delivery presented. Of specific interest is the use of cyclodextrin-containing polymers to provide unique capabilities for the delivery of nucleic acids.

Oral oestrogen and combined oestrogen/progestogen therapy versus placebo for hot flushes

BACKGROUND

Hot flushes and night sweats are common symptoms experienced by menopausal women. Hormone therapy (HT), containing oestrogens alone or oestrogens together with progestogens in a cyclic or continuous regimen, is often recommended for their alleviation.

OBJECTIVES

To examine the effect of oral HT compared to placebo on these vasomotor symptoms and the risk of early onset side-effects.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders Group and Subfertility Group trials register (searched May 2002). This register is based on regular searches of MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, the handsearching of 20 relevant journals and conference proceedings, and searches of several key grey literature sources. We also contacted all relevant pharmaceutical companies, The Journal of the International Menopause Society and Climacteric.

SELECTION CRITERIA

Double-blind, randomised, placebo-controlled trials of oral HT for at least three months duration.

DATA COLLECTION AND ANALYSIS

Study quality and outcome data were assessed independently. Random effects models were considered appropriate due to the variety of trial methodologies. The meta-analyses were explored for sensitivity to trial quality and therapy duration. Symptom frequency and severity were assessed separately, together with withdrawals and side-effects. Frequency data were analysed using the Weighted Mean Difference (WMD) between treatment and placebo outcomes. For severity data, odds ratios were estimated from the proportional odds model. From 115 references originally identified, 24 trials meeting the selection criteria were included in the review. Study participants totaled 3,329. Trial duration ranged from three months to three years.

MAIN RESULTS

There was a significant reduction in the weekly hot flush frequency for HT compared to placebo (WMD -17.92, 95% CI -22.86 to -12.99). This was equivalent to a 75% reduction in frequency (95% CI 64.3 to 82.3) for HT relative to placebo. Symptom severity was also significantly reduced compared to placebo (OR 0.13, 95% CI 0.07 to 0.23). Withdrawal for lack of efficacy occurred significantly more often on placebo therapy (OR 10.51, 95% CI 5.00 to 22.09). Withdrawal for adverse events, commonly breast tenderness, oedema, joint pain and psychological symptoms, was not significantly increased (OR 1.25, 95% CI 0.83 to 1.90), although the occurrence of any adverse events was significantly increased for HT (OR 1.41, 95% CI 1.00 to 1.99). In women who were randomised to placebo treatment, a 57.7% (95% CI 45.1 to 67.7) reduction in hot flushes was observed between baseline and end of study.

REVIEWERS' CONCLUSIONS

Oral HT is highly effective in alleviating hot flushes and night sweats. Therapies purported to reduce such symptoms must be assessed in blinded trials against a placebo or a validated therapy because of the large placebo effect seen in well conducted randomised controlled trials, and also because during menopause symptoms may fluctuate and after menopause symptoms often decline. Withdrawals due to side-effects were only marginally increased in the HT groups despite the inability to tailor HT in these fixed dose trials. Comparisons of hormonal doses, product types or regimens require analysis of trials with these specific "within study" comparisons.

Drug delivery systems for oestrogenic hormones and antagonists: the need for selective targeting in estradiol-dependent cancers

The pleiotropic activity of oestrogens and their mechanism of action via their binding to the two oestrogen receptors alpha (ER alpha) and beta (ER beta) subtypes in the different tissues where oestrogens exert their action have been briefly described. The fate of these compounds trapped into different galenic forms is discussed with regard to their therapeutic applications. Firstly, the advantages and disadvantages of the different forms (pills, i.v. forms and transdermal patches) used in contraception are compared. Secondly, the therapeutic use of formulated oestrogens for the post-menopausal hormone replacement therapy (HRT) is analysed through the various results obtained in different trials. The link between HRT and the risks of breast cancer and cardiovascular disease is underlined. Finally, comparing the activity of selective oestrogen receptor modulators such as tamoxifen and pure anti-oestrogens such as RU58668 and ICI182780, we analysed the reasons leading to the need for a tumor targeting of the latters, but not of the former for the treatment of oestrogen-dependent breast cancer. Different injectable and biodegradable formulations, that lead to a remarkable anti-tumor efficiency in xenografts, have been recently developed and we believe that they may represent promising new administration ways of added therapeutic values for anti-oestrogens. Such devices could be extended to the delivery of other anti-cancer drugs with more aggressive activities than anti-oestrogens.

Skin contamination by oestradiol gel—a remarkable source of error in plasma oestradiol measurements during percutaneous hormone replacement therapy

OBJECTIVES

To study the consequence of skin contamination by oestradiol gel on circulating plasma oestradiol levels.

METHODS

We studied ten healthy, hysterectomized postmenopausal women who had used percutaneous oestradiol gel for at least 2 years. After wash-out period percutaneous dose of 1.5 mg 17beta-oestradiol was administered once a day in the evening. The gel was applied with a bare or gloved hand to an arm or thigh according to the schedule. Blood samples for assay of plasma oestradiol concentrations were collected from both cubital veins 12 h after gel administration, at baseline and every time after using the gel, for 2 weeks.

RESULTS

Plasma oestradiol concentrations were significantly higher in the gel-contaminated samples: in the cubital vein of the gel-applying arm and in the cubital vein of the forearm on which the gel had been spread.

CONCLUSIONS

Skin contamination by topical 17beta-oestradiol can distort plasma oestradiol measurements by giving much higher oestradiol concentrations than in reality there are in the systemic circulation. This has an important meaning when tailoring individual oestrogen therapy.

Uptake of estradiol or progesterone into the CSF following intranasal and intravenous delivery in rats

The uptake of estradiol and progesterone into the cerebrospinal fluid (CSF) after intranasal and intravenous administration in rats was investigated. Each animal received estradiol intranasally (40 microg/rat) and by intravenous infusion (10 microg/rat) into the jugular vein using a vascular access port. Hereafter, the same set of rats was treated with progesterone intranasally (200 microg/rat) and by intravenous infusion (104 microg/rat). Following nasal delivery, both steroid hormones reach Cmax values in plasma and CSF at 15 min after administration. Intravenous infusion of estradiol and progesterone shows comparable plasma and CSF concentration-time profiles compared to the nasal route. For both hormones the AUCCSF/AUCplasma ratios (mean +/- SD) after intranasal delivery (estradiol 2.3 +/- 1.1%; progesterone 1.9 +/- 0.7%) do not differ significantly from the ratios shown after intravenous infusion (estradiol 2.0 +/- 0.6%; progesterone 2.2 +/- 0.8%). These results indicate that after nasal delivery estradiol and progesterone are rapidly absorbed into the systemic circulation, from where the non-protein bound hormones probably enter the CSF by crossing the blood-brain barrier. No extra direct nose-CSF transport could be demonstrated.

Prevention of postmenopausal bone loss by pulsed estrogen therapy: comparison with transdermal route

OBJECTIVE

To compare the efficacy of pulsed estrogen therapy following intranasal 17beta-estradiol (E2) (S21400) with patch E2 in preventing postmenopausal bone loss and on bone turnover.

METHODS

In this multinational open study, 361 postmenopausal women aged 51.5 (S.D. 4.6) years were treated with S21400 300 microg per day or patch E2 (delivering 50 microg per day), two patches per week, for 56 weeks. Bone mineral density (BMD) was assessed at the spine and hip using dual X-ray absorptiometry at baseline and week 56 (W56). Bone turnover markers (osteocalcin, bone alkaline phosphatase, urinary type I collagen C-telopeptides) were measured at baseline and weeks 12, 28 and 56.

RESULTS

Spine and hip bone mineral density significantly increased in both groups (P < 0.001 versus baseline). Mean (S.D.) percent increases were 2.1 (3.0) at the spine (both groups), and 1.2 (2.4) and 1.1 (2.2) at the hip in the S21400 and patch E2 groups, respectively. Bone mineral density also significantly increased (P < 0.001 versus baseline) in osteopenic patients following S21400 and patch E2: 3.1 (3.5) and 2.4 (3.5) at the spine, and 2.0 (2.6) and 1.2 (2.7) at the hip, respectively. Bone metabolism was normalized at week 56 with a significant decrease (P < 0.001) from baseline in all markers: 56% and 53% for type I collagen C-telopeptides, and 24% and 25% for osteocalcin in the S21400 and patch E2 groups, respectively.

CONCLUSION

Pulsed estrogen therapy was as effective in normalizing bone turnover and preventing postmenopausal bone loss as a reservoir patch.

Pulsed estrogen therapy in prevention of postmenopausal osteoporosis. A 2-year randomized, double blind, placebo-controlled study

The aim of this study was to evaluate the efficacy of pulsed estrogen therapy (intranasal 17beta-estradiol) in the prevention of postmenopausal bone loss. A total of 386 women (40-65 years old), less than 5 years past menopause, were randomized to intranasal placebo, 17beta-estradiol 150 micro g, or 300 micro g daily for 2 years. Women with an intact uterus received micronised progesterone 200 mg per day, 14 days of each 28-day cycle. Women randomised to placebo-treatment received placebo progesterone. The primary endpoints were changes in BMD at the spine (L2-L4) and femoral neck. Secondary endpoints were changes in bone turnover markers: serum osteocalcin (sOC) as a marker of bone formation and urinary C-terminal telopeptides (uCTX) as a marker of bone resorption. BMD increased at all measured sites in women receiving active treatment in a dose-related manner, the difference compared to placebo being 5.2% and 6.7% at the spine, and 3.2% and 4.7 % at the hip, respectively, with 150 microg and 300 microg ( P<0.001). On the other hand, a decrease versus baseline of -3.2% and -3.3% at the spine and hip, respectively, was observed in women receiving placebo ( P<0.001). In the patients with at least one risk factor for osteoporotic fracture, the difference between placebo and 150 microg or 300 micro g was even higher at the spine (5.4% and 7.4%, respectively), and at the femoral neck (4.0% and 5.2%, respectively). Correspondingly, uCTX decreased from baseline by 39% and 46 %, and sOC by 22% and 27%, in the 150 micro g group and 300 micro g group (all P<0.001 versus placebo). A strong correlation was found between variations of bone turnover markers after 1 year and BMD after 2 years, emphasizing that bone markers can predict BMD response during hormonal treatment. Acceptability and general tolerance were good. This study demonstrates that pulsed estrogen therapy at the dose of 150 microg and 300-microg per day prevents bone loss in a dose-dependant manner at each site studied, and normalizes bone turnover markers to premenopausal levels.

Overview on the effects of progestins on bone

In view of the fact that fractures are the clinically relevant events, risk factors for fractures are discussed first. Bone mineral density (BMD) appears to be a much less important risk factor for the most severe hip fractures than the risk of falling. No results of experimental studies on hormones and fractures at advanced age are available. An overview of the effects of progestins on bone is given. Effects of progestins on bone have been studied by in vitro experiments using cell lines and by more relevant clinical observations. Prospective studies have been conducted following the use of progestins contained in oral contraceptives, alone or in combination with oestrogens; long-term contraception by injection of depot preparations; so-called "add-back" hormonal therapy attempting to reverse the adverse effects of gonadotropin releasing hormone agonists on bone and after different regimens of hormone replacement therapy (HRT) in postmenopausal women. From the data there are no indications that the various progestins, used in clinical practice, have either a bone-protective or an oestrogen antagonistic activity. Progestins do not add or subtract much of the protective action of oestrogens on the bones.

Impact of different progestins on endometrial vascularisation of postmenopausal women. A retrospective image analysis—morphometric study

OBJECTIVES

To determine if the vascularisation of the endometrium is dependent on the administered progestin during sequential hormone replacement therapy.

METHODS

Nine women received percutaneous estradiol-17 beta, 1.5 mg/day from days 1 to 24 combined with 200 mg/day micronised progesterone from days 11 to 24 of the treatment cycle. Fifteen women received percutaneous estradiol, 1.5 mg/day from days 1 to 24, combined with 10 mg/day chlormadinone acetate from days 11 to 24. Eleven women received percutaneous estradiol, 50 microg/day from days 1 to 28 combined with percutaneous norethisterone acetate, 0.3mg/day form days 14 to 28. Twelve women received intranasal estradiol, 300 microg/day from days 1 to 25 combined with 0.5 mg of promegestone from days 11 to 24. Eleven spontaneous cycling women had an endometrial biopsy during luteal phase and served as controls. Endometrial biopsies were processed routinely between days 18 and 24 and sections were immunostained using anti-CD34 antibody to identify vascular endothelial cells, which were treated with an automatic image analysis system.

RESULTS

mean (+/-S.D.) vascular density for controls was 147+/-41.5 vessels/mm(2), with mean vessel area of 143+/-60.9 microm(2). In chlormadinone users endometrial microvascular density and mean vessel area did not differ from the control group (150.2+/-58.6 and 152.9+/-70.5). The other three progestins generated a significant increase of mean vessel density, 179.6+/-51.6 with micronised progesterone, 178.5+/-67.6 with norethisterone and 179.6+/-48.4 with promegestone. The mean vessel area was lower in the latter three groups, respectively, 108.4+/-39.0, 97.5+/-46.5 and 141.6+/-66.7 microm(2), promegestone leading to non significant difference with control.

CONCLUSION

regarding vascularisation, chlormadinone and control group gave similar patterns. Promegestone was associated with an increase of the number of vessels, as did micronised progesterone or norethisterone; the mean vascular area was the smallest in the norethisterone group.

Menopause: new therapies

The risk-benefit ratio of traditional postmenopausal hormone therapy is considered by many to be unacceptable. Low-dose oestrogen-progestin therapy (oral or non-oral and continuous or pulsatile) may have a better risk-benefit ratio, but this remains unproven. Steroids with selective tissue activation, such as tibolone, alleviate symptoms and protect against bone loss, but long-term safety data are lacking. Selective oestrogen receptor modulators (SERMs), such as raloxifene, prevent bone loss when used alone, and may soon be combined with oestradiol to treat symptoms and prevent osteoporotic fracture. Effects of SERMs on the cardiovascular system are currently being evaluated.

Hormone replacement therapy: optimising the dose and route of administration

Several new products and regimens for estrogen replacement in the postmenopausal woman have recently been introduced, giving physicians and patients greater choice not only in dose but also in route of administration. Estrogen treatment in the postmenopausal woman has several proven benefits for those who have vasomotor symptoms or problems related to urogenital atrophy. However, the most controversial area is in the long-term preventive benefits of estrogen against the development of osteoporosis and cardiovascular disease, particularly in women older than 60 years. It is in these areas that decisions on the dose and optimal route of administration of estrogen replacement therapy (ERT) must be made. Although adding a progestogen to an ERT regimen is mandatory, particularly in a woman with an intact uterus, discussion now focuses on which progestogen least attenuates the beneficial effects of estrogen. Emerging trends suggest that lower doses of estrogen (i.e. ethinylestradiol 5 microg/day, estradiol 0.25 mg/day or conjugated estrogens [CEE] 0.3 mg/day) continuously combined with lower doses of medroxyprogesterone (MPA) are equally effective at relieving vasomotor symptoms as the most commonly prescribed regimen in the US (CEE 0.625mg/MPA 2.5mg daily), with fewer adverse events, leading to greater patient acceptance and likelihood for continuation of therapy. This is especially important when therapy is initiated at an older age.

Intranasal hormone replacement therapy

Although the optimal route of delivery for hormone replacement therapy has not yet been determined, desirable qualities would include good efficacy, easy administration, minimal side effects, and optimal therapeutic profile. This would potentially serve to improve patient compliance and satisfaction. The intranasal route has been evaluated for the administration of menopausal hormones and seems to fulfill these requirements. The intranasal route would also seem to be a viable alternative for drugs that are poorly absorbed after ingestion by avoiding hepatic first-pass elimination. The intranasal route is, therefore, innovative for the delivery of natural sex steroids in postmenopausal women receiving hormone replacement therapy. Early studies demonstrate that it is safe, effective, and acceptable to postmenopausal women. In addition, the nasal administration of a combination of estradiol and progesterone would seem to be an attractive way to deliver hormones to nonhysterectomized postmenopausal women. Providing alternative routes of administration may also enhance compliance.

Oral ascorbic acid increases plasma oestradiol during postmenopausal hormone replacement therapy

OBJECTIVES

To study the possible interaction between ascorbic acid (AA) and oestradiol (E2) in postmenopausal women on hormone replacement therapy (HRT).

METHODS

We studied 25 healthy postmenopausal women who had used percutaneous E2 gel at same dose for 10-12 months, at which time the plasma E2 concentrations were stabilized. The subjects were treated with 1000 mg of AA daily for 3 months and blood samples for assay of AA and E2 were taken at 0, 1 and 3 months.

RESULTS

After 1 month of AA treatment, there was an overall increase of 20.8% in E2 levels in the group as a whole. Greater responses were seen in two subgroups. In women with initially the lowest plasma concentrations of AA (<70 micromol/l), there was an increase of 55% in plasma E2 levels which was close to significance (P=0.063). In another subgroup with initially the lowest E2 levels (<0.20 nmol/l) there was a marked and significant increase (from 0.13 to 0.26 nmol/l) in plasma E2 concentrations (P=0.028).

CONCLUSIONS

Our results support early findings that AA may interact with oestrogen therapy. Possible interaction of AA with E2 at the level of antioxidation is discussed.

The influence of the route of administration of 17beta-estradiol, intravenous (pulsed) versus oral, upon DMBA-induced mammary tumour development in ovariectomised rats

A wide variety of routes of administration and formulations are employed in estrogen replacement therapy. These exhibit differences in the pharmacokinetics and metabolism of estradiol and in the resulting biological effects. This study set out to investigate the effects of pulsed estrogen administration (via the nasal route) compared to oral therapy, as a reference, with regard to breast cancer risk. This was assessed in an experimental model whereby mammary tumours were induced by 7,12-dimetbylbenz(a)anthracene in ovariectomised rats. To mimic a pulsed treatment given via the nasal route doses of estrogen were administered by I.V. route (0.4, 10 and 250 microg/kg). These dosages were predicted to have similar estrogenic activity to doses administered by the oral route (100, 300 and 900 microg/kg). Controls were groups of ovariectomised and SHAM-operated rats and ovarectomised rats administered with either vehicle alone. Two studies were carried out on separate populations of rats and ran in parallel. Tumour appearance (study 1) and tumour growth (study 2) were evaluated. In study I (n = 20/group), treatments with estradiol were conducted for 20 weeks after carcinogen administration; in study 2 (n = 10/group), an 8-week treatment with estradiol was initiated once 7,12-dimethylbenz(a)anthracene-induced tumours appeared. Intravenous dose levels achieved equivalent estrogenicity to corresponding oral dose levels, as assessed by measuring uterus weight. Estrogen deficit was made up by both routes but only the higher doses restored physiological uterus weight. Nevertheless administration via the I.V. route resulted in a lower rate of tumour incidence (p < or = 0.05) than the rate recorded for the oral route. In addition, tumour development was lower with the I.V. route. In conclusion, in this experimental model, pulsed estrogen therapy with 17beta-estradiol administered via the I.V. route resulted in a reduced effect on mammary carcinogenesis when compared to oral administration.

Efficacy of a new 7-day transdermal sequential estradiol/levonorgestrel patch in women

OBJECTIVE

To investigate the efficacy and tolerability of a new 7-day transdermal sequential estradiol/levonorgestrel patch (Fem7 Combi; Merck KGaA; Germany), versus placebo, as hormone replacement therapy in menopausal women.

METHODS

A multicentre, randomized, clinical study consisting of a 3-week screening phase, a 12-week double-blind, placebo-controlled treatment phase, and a 12-week open, follow-up phase. Women aged 40-65 years with an intact uterus and menopausal complaints were randomized to either 2 weeks of an estradiol mono patch (50 microg per 24 h) followed by 2 weeks of an estradiol/levonorgestrel combination patch (50 microg/10 microg per 24 h), or a placebo patch, for three 28-day cycles. Changes in the Kupperman Index and the frequency of hot flushes were assessed.

RESULTS

The sequential use of a 7-day estradiol patch and a 7-day estradiol/levonorgestrel patch was superior to placebo in reducing menopausal symptoms, and was well tolerated. At the end of the treatment phase, there was a statistically significant reduction in the Kupperman Index score versus placebo (P<0.0001), and a statistically significant difference between groups in the proportion of patients with a reduction in the number of hot flushes (at least 50% versus baseline). During the open follow-up phase, there was a marked reduction in the Kupperman Index score and the number of hot flushes for patients switched from placebo to active study medication. The active medication was effective throughout the 1-week application period.

CONCLUSIONS

The new 7-day transdermal sequential estradiol/levonorgestrel patch was well tolerated, providing rapid and effective relief of menopausal symptoms. The addition of low-dose levonorgestrel did not influence the beneficial effects of estradiol.

Estradiol-intranasal: a review of its use in the management of menopause

Estradiol-intranasal is a nasal spray formulation containing an aqueous solution of 17beta-estradiol that has a unique pulse-like pharmacokinetic profile. In a well designed, placebo-controlled trial estradiol-intranasal 200 to 400 microg/day significantly reduced the incidence and severity of climacteric symptoms in women with moderate to severe menopausal symptoms after 4 and 12 weeks' treatment. The efficacy of estradiol-intranasal 300 microg/day was similar to that of oral estradiol 2 mg/day in this and another double-blind placebo-controlled trial. This equivalent efficacy was maintained in a subgroup of women with initially severe symptoms, and in smokers. Reductions in the incidence of atrophic vaginal mucosa and genitourinary symptoms and increases in the karyopyknotic index achieved with estradiol-intranasal 300 microg/day were also similar to those observed with oral estradiol 2 mg/day. Assessments of the effects of estradiol-intranasal on the complications of menopause (increased risk of cardiovascular disease and osteoporosis) are ongoing; however, estradiol-intranasal (sequentially combined with a progestogen) produced significant beneficial effects on some lipid parameters and on markers of bone resorption and formation, and bone mineral density in postmenopausal women. Estradiol-intranasal had no significant effects on serum levels of most of the assessed haemostatic factors, or on angiotensinogen or insulin levels. Estradiol-intranasal 100 to 600 microg/day was generally well tolerated in clinical trials and most adverse events were mild to moderate. The most commonly reported events were nasal symptoms and mastalgia. There was no evidence of endometrial hyperplasia with up to 1 year's treatment with estradiol-intranasal 300 microg/day combined with a progestogen. The incidence of mastalgia and withdrawal or breakthrough bleeding was lower with estradiol-intranasal 300 microg/day than with oral estradiol 2 mg/day (both administered with a progestogen) in one trial. In another trial, the incidence of mastalgia was lower with estradiol-intranasal 300 microg/day than with estradiol transdermal 50 microg (both administered with a progestogen). However, the overall incidence of adverse events was similar between the two treatments in this trial.

CONCLUSIONS

Estradiol-intranasal 200 to 400 microg/day (optimal initiating dose 300 microg/day) reduces the incidence and severity of menopausal climacteric symptoms and has a good tolerability profile. Thus, evidence to date suggests that estradiol-intranasal is a useful treatment option for menopausal symptoms.

Therapeutic value and long-term safety of pulsed estrogen therapy

OBJECTIVES

To demonstrate equivalent efficacy for menopausal symptoms between Aerodiol nasal spray and reference oral estradiol therapy, and to investigate the endometrial safety and tolerability of Aerodiol in the long term.

METHODS

The efficacy of Aerodiol 300 microg, once daily, was compared with oral estradiol 2 mg/day in a randomized, double-blind trial. A statistical test of noninferiority was performed on the mean absolute Kupperman index (KI) obtained after 14 and 23 weeks of the two treatments. Long-term safety was assessed in a 1-year open-label study. The initial Aerodiol dose was 300 microg/day, and was adjusted if required. Endometrial biopsies were obtained at inclusion and at the end of the trial and examined independently by two pathologists.

RESULTS

In the equivalence trial, the KI improved similarly in the Aerodiol group (n=317) and the oral estradiol group (n=342). Aerodiol was shown statistically to be at least as effective as oral therapy (P<0.001), but the incidences of mastalgia and withdrawal bleeding were significantly lower in the Aerodiol group (P<0.01 and P<0.001, respectively). In the long-term safety trial (n=408), the rate of Aerodiol treatment continuation at 12 months was 85%, and there was no incidence of endometrial hyperplasia or cancer. Aerodiol dose adaptation was performed by 29% of women.

CONCLUSIONS

Aerodiol was shown to have equivalent efficacy to reference oral estradiol therapy, but with better gynaecological acceptability. The endometrial safety of Aerodiol was confirmed in the long term, and the ability to adjust the dosage easily was of benefit to a substantial proportion of women.