A risk-benefit appraisal of transdermal estradiol therapy

Combined ethinylestradiol/gestodene contraceptive patch: two-center, open-label study of ovulation inhibition, acceptability and safety over two cycles in female volunteers

OBJECTIVES

Determination of the ovulation inhibition efficacy of a new, transparent, transdermal, combined hormonal contraceptive patch (area 10 cm2) containing 0.9 mg ethinylestradiol and 1.9 mg gestodene in an open-label study of healthy, female volunteers (aged 18-35 years).

METHODS

A total of 199 volunteers from two centers were requested to use the contraceptive patch (one patch/week for 3 weeks, followed by 1 week of no treatment), throughout two menstrual cycles. Ovarian activity was monitored by transvaginal ultrasonography and serum hormone determinations, and classified according to the Hoogland score.

RESULTS

Ovulation inhibition was achieved in all participants (Hoogland score < 6). Secondary efficacy measures, including suppression of serum concentrations of estradiol and progesterone, and of the mid-cycle luteinizing hormone surge, confirmed ovulation inhibition. Ovulation returned in 85.7% of participants during the first cycle after cessation of treatment. There were no abnormal changes in safety parameters. A large majority of users rated the contraceptive patch as 'very convenient'.

CONCLUSIONS

This study showed that the new, combined ethinylestradiol/gestodene contraceptive patch was highly effective in reversibly inhibiting ovulation, well tolerated and regarded as 'very convenient' by the majority of users. This new, transparent, transdermal matrix patch is an attractive alternative form of contraception.

Treatment strategies for hot flushes

BACKGROUND

Vasomotor symptoms are the most common complaints for which menopausal women seek medical care. Eighty per cent of all menopausal women will have hot flushes and night sweats, and of these 9% will have severe symptoms impacting their quality of life. Ideally, treatment should target the group most severely afflicted, and options for treatment should be tailored to each woman, since, for most women, vasomotor symptoms spontaneously resolve in 3 - 5 years. Recommendation at this time is for the shortest duration of therapy, which means that episodic review of therapy is indicated.

OBJECTIVE

To review the latest literature investigating therapies for vasomotor symptoms and to discuss their effectiveness with emphasis on placebo-controlled, randomized clinical trials.

METHODS

A literature search in PubMed for 'vasomotor symptoms', 'menopause symptoms', 'hot flushes', 'hot flashes' and 'night sweats' from 2003 to the present was performed.

CONCLUSIONS

Estrogen remains the gold standard for treating vasomotor symptoms. As investigations into the physiology of hot flushes continue, centrally active drugs (selective serotonin or norepinephrine-serotonin reuptake inhibitors and gabapentin) have increased in use. The benefit from dietary herbal supplements is still inconclusive; however, recent studies have shown some mild response to soy and black cohosh.

Serum concentrations of 17beta-estradiol and estrone after multiple-dose administration of percutaneous estradiol gel in symptomatic menopausal women

In two multicenter phase III efficacy studies, blood samples were obtained to evaluate the serum concentrations of 17beta-estradiol (E2) and unconjugated estrone (E1) after administration of a percutaneous gel or transdermal patch containing estradiol. In postmenopausal women, normal laboratory E2 and E1 serum concentrations range from 10-30 pg/mL and 20-40 pg/mL, respectively. Study subjects were healthy postmenopausal women with moderate to severe hot flushes occurring at least seven times daily or 60 times per week. Study 1 was a randomized, double-blind, multicenter study of percutaneous E2 gel 1.25 or 2.5 g (0.75 and 1.5 mg E2, respectively) versus placebo gel. Study 2 was a double-blind (blinded to E2 gel dose), randomized, active-controlled, multicenter, 12-week phase 3 study of E2 gel 0.625, 1.25, or 2.5 g (0.375, 0.75, or 1.5 mg E2, respectively) versus a transdermal E2 patch delivering 0.05 mg E2 per day. Serum E2 and E1 concentrations were evaluated at baseline and at week 12 for study 1 and at baseline and weeks 4, 8, and 12 for study 2 using radioimmunoassay. Median serum concentrations of E2 after 1.25- and 2.5-g gel administration appeared to be dose-proportional throughout both studies. In study 1, the median serum concentrations of E2 at week 12 were 33.5 and 65.0 pg/mL for 1.25- and 2.5-g gel dose, respectively. The corresponding E1 values were 49.0 and 58.0 pg/mL. In study 2, both E2 and E1 concentrations were relatively stable at weeks 4, 8, and 12. E2 values at week 12 for 0.625-, 1.25-, and 2.5-g gel doses and E2 patch were 25.0, 32.0, 60.0, and 38.5 pg/mL, respectively. The corresponding E1 values were 39.0, 41.0, 62.5, and 40.0 pg/mL. Application of the 1.25-g gel dose and a transdermal patch delivering 50 microg per day of E2 resulted in comparable median E2 and E1 concentrations. However, the 0.625-g gel dose did not produce E2 levels in a range expected to be consistently therapeutic in most postmenopausal women.

Drug concentration effect relationship of estradiol from two matrix transdermal delivery systems: Menorest and Climara

OBJECTIVES

To relate the pharmacokinetics of estradiol to pharmacological effects.

METHODS

Drug concentration effect relationship of estradiol from two matrix transdermal delivery systems, Menorest and Climara, was studied in a single centre, open, randomised, comparative crossover study. The trial consisted of two treatment periods, 14 days for each patch separated by a 4-week washout period. Blood hormone levels were followed during the second week of each treatment. Estradiol levels during treatments were related to three concentration levels previously proposed as efficacy or safety limits. The effect of treatment on FSH-levels was examined and the relationship between the levels of estradiol and FSH was described using an inhibitory sigmoidal I(max) model. Estrone levels and estradiol/estrone before and during treatment were followed.

RESULTS

The C(average) of FSH during treatment was 38% lower than baseline plasma levels. Estradiol had an inhibitory effect on FSH with an I(max) of 0.68 and an IC(50) of 19 pg/ml. The fraction of time above the minimum concentration for therapeutic effect and the tolerability limit did not differ between the two treatments, whereas the fraction of time above the suggested threshold for osteoporosis prophylaxis was significantly larger for Menorest than for Climara (P<0.05). The low baseline estradiol/estrone ratios increased towards pre-menopausal levels during treatment.

CONCLUSIONS

The drug concentration effect relationship of estradiol may be of use in evaluation of the effects of prophylactic estrogen therapy and to facilitate comparisons between different forms of estrogen treatments.

Bioavailability of estradiol from two matrix transdermal delivery systems: Menorest and Climara

OBJECTIVES

To compare two estradiol transdermal matrix systems with regard to bioavailability, pharmacokinetics and tolerability.

METHODS

A single centre, open, randomized, comparative cross-over study in 20 healthy postmenopausal women. Menorest with 3 or 4 days of suggested use and Climara with 7 days of suggested use (both 50 microg/24 h) were compared at steady state. Two 14-day treatment periods were separated by a 4 week washout. Plasma levels of estradiol were monitored during the second week of each treatment. Tolerability was assessed by open questions and inspection of the application site.

RESULTS

There were no differences between the two treatments with regards to AUC, Cmax, Cmin, Caverage or fluctuations of plasma estradiol. Tmax was significantly shorter for Menorest than Climara. Cmax and Cmin were significantly higher for the second Menorest patch during the monitoring period compared to the first. All local reactions were mild and there were three cases of erythema with Menorest and a total of 21 skin reactions in 15 subjects with Climara. Systemic tolerability was similar between treatments with eight estrogen-related adverse events in eight subjects (period pains, uterine bleeding, mastodynia, headache and vaginal discharge) with Menorest and 13 events in ten subjects with Climara.

CONCLUSIONS

The bioavailability of estradiol from the two matrix transdermal delivery systems Menorest and Climara was similar, but the products were not bioequivalent because Tmax was significantly shorter for Menorest than for Climara. Tolerability of treatment was good for both patches but with a higher number of local reactions and estrogen related adverse events for Climara.

Efficacy and tolerability of a new estradiol delivering matrix patch (Estraderm MX) in postmenopausal women

OBJECTIVE

To examine the efficacy and tolerability of a new matrix patch delivering estradiol (E2 Matrix) at doses of 0.05 and 0.10 mg per day (Estraderm MX 50, 100) in the treatment of moderate to severe postmenopausal symptoms.

METHODS

A total of 254 postmenopausal women were randomized to receive treatment with E2 Matrix 0.10 mg (N = 86), E2 Matrix 0.05 mg (N = 82), or placebo (N = 86) in a double-blind, double-dummy fashion for a period of 12 weeks continuously. Patches were applied twice weekly to the buttocks with each patient wearing two patches at all times. The primary efficacy criterion was the difference from baseline of the mean number of moderate to severe hot flushes per 24 h during the last 2 weeks of treatment. Other efficacy variables included reduction in hot flushes at 4 and 8 weeks, reduction in daytime flushing and night sweats, and Kupperman Index at 4, 8, and 12 weeks.

RESULTS

E2 Matrix 0.10 and 0.05 mg were both significantly superior to placebo in reducing hot flushes per 24 h after 4, 8, and 12 weeks of treatment (P < 0.001). Also, for all other efficacy parameters studied, both dosage strengths of E2 Matrix were statistically significantly superior to placebo at all time points (P < 0.001). Local tolerability was good in both groups. A slight increase in estrogen related adverse effects (breast tenderness, leukorrhoea) was seen with the 0.10 mg patch. Adhesion of patches and compliance were good. Overall systemic tolerability was good in both treated groups. However, a 4.8% overall incidence of endometrial hyperplasia was observed in patients with an intact uterus.

CONCLUSIONS

This new matrix patch offers an effective and well tolerated dosage form for delivery of 0.05 and 0.1 mg estradiol per day. It may be particularly suitable for those women who experience local sensitivity to alcohol-containing systems. In light of the observed hyperplasia after treatment in five patients, estrogen therapy should as yet be supplemented monthly with a progestogen in women with an intact uterus.

Comparison of the transdermal delivery of estradiol from two gel formulations

OBJECTIVE

Conventional oral oestrogen replacement therapy can relieve postmenopausal symptoms but is associated with undesirable side-effects which can be minimised by avoiding the fluctuating hormonal blood levels resulting from oral therapy and eliminating hepatic first-pass metabolism by the use of the transdermal route. The two commercially available transdermal gel formulations differ in composition and application recommendations. Sandrena Gel contains 0.1% (w/w) and Oestrogel 0.06% (w/w) estradiol and recommended dosages are 0.5-1.5 g over 200-400 cm2 (Sandrena Gel) and 2.5 g gel over 720 cm2 (Oestrogel). In transdermal therapy the formulation composition may have a significant effect on drug delivery and we have therefore compared the permeation of estradiol from these formulations across human skin in vitro.

METHODS

The in vitro percutaneous penetration of estradiol from the formulations through epidermal membranes prepared from excised female human thing skin was assessed over a 24 h period using static type Franz diffusion cells.

RESULTS

Permeation of the active was similar from each formulation representing (at 24 h) 18.2 +/- 3.5% of the applied dose from Sandrena Gel and 17.4 +/- 4.8% of the applied dose from Oestrogel. These percentages equate to cumulative skin permeations of 0.65 +/- 0.15 microgram/cm2 and 0.45 +/- 0.15 microgram/cm2 respectively.

CONCLUSION

The results suggest that the two formulations are bioequivalent at the recommended dose levels.

Steady-state pharmacokinetics of oestradiol gel in post-menopausal women: effects of application area and washing

OBJECTIVE

To investigate the effect of cutaneous application area on oestradiol absorption using an oestradiol gel for transdermal use. Furthermore, the effect of washing of the application site on oestradiol pharmacokinetics was studied.

DESIGN

Open-label, randomised, three-way cross-over study.

SETTING

A clinical pharmacokinetic research unit.

SUBJECTS

Sixteen healthy postmenopausal volunteers.

INTERVENTIONS

During three treatment periods, subjects were treated with 1 mg oestradiol (1.0 g Divigel/Sandrena 0.1% gel), applied on the thigh to a skin area of 200 cm2, 400 cm2, or on an area 'as large as possible'. Blood samples were drawn during steady-state (on days 14-15) immediately before application and at regular time intervals thereafter.

MAIN OUTCOME MEASURES

Serum oestradiol levels were measured for determination of peak concentration (Cmax), time to peak concentration (tmax) and bioavailability using the area under the time concentration curve (AUC0-24).

RESULTS

Bioavailability from a 200 cm2 area was 2-fold higher than that from the largest possible area (P < 0.05). Oestradiol peak plasma concentration from a 200 cm2 area was higher than from the two larger areas (P < 0.05), which did not differ significantly from each other. Washing of the application site 30 min after application reduced the bioavailability from both the 200 cm2 and 400 cm2 application areas (P < 0.01), but peak plasma concentration from the 200 cm2 area only (P < 0.01). Time to reach peak plasma concentrations was significantly reduced with all three application areas by washing.

CONCLUSION

A higher oestradiol absorption was achieved from a smaller application area. No marked differences were observed in the pharmacokinetics between 200 cm2 and 400 cm2 application areas, which are those recommended for this oestradiol gel preparation.

Efficacy and tolerability of Estraderm MX, a new estradiol matrix patch

OBJECTIVES

To assess the efficacy and tolerability of a new matrix patch delivering 0.05 mg estradiol per day (Estraderm MX 50) in postmenopausal women with moderate to severe postmenopausal symptoms.

METHODS

A multicenter, double-blind, randomized, between-patient, placebo controlled trial in 109 postmenopausal women was carried out. Patches were applied twice weekly for 12 weeks. Patients were assessed at 4, 8 and 12 weeks of treatment. The primary efficacy variable was change from baseline in mean number of moderate to severe hot flushes (including night sweats) per 24 h during the last 2 weeks of treatment. Other variables included Kupperman Index, local and systemic tolerability. Plasma concentrations of estradiol (E2), estrone (E1) and estrone sulfate (E1S) were determined before and after treatment.

RESULTS

Estraderm MX was significantly superior to placebo (P < 0.001) in reducing mean number of moderate to severe hot flushes (including night sweats) per 24 h after 4, 8 and 12 weeks of treatment. The estimate of treatment group differences after 12 weeks was 4.2 hot flushes (95% confidence interval: 2.6-5.8). Estraderm MX also significantly reduced Kupperman Index at all time points compared to placebo (P < 0.001). Estraderm MX induced increases in mean E2, E1 and E1S plasma levels as expected (E2: baseline 2.7 pg/ml, 12 weeks 38.9 pg/ml; E1: baseline 18.8 pg/ml, 12 weeks 41.6 pg/ml; E1S: baseline 235.6 pg/ml, 12 weeks 765.1 pg/ml). Overall rates of adverse experiences were similar for Estraderm MX and placebo. The number of patients reporting skin irritation was low and similar in both groups.

CONCLUSIONS

Estraderm MX 50, a new matrix patch, offers an effective and well tolerated dosage form for transdermal delivery of 0.05 mg E2 per day.

Transdermal estrogen therapy

Estrogen replacement therapy is becoming an important weapon in the fight against osteoporosis and heart disease in postmenopausal women, in addition to its original role of alleviating many of the symptoms associated with menopause. Dr. Connell discusses the many benefits of estrogen replacement therapy and the advantages that transdermal administration of estrogen appear to offer over other routes of administration.

Plasma estradiol concentrations and pharmacokinetics following transdermal application of Menorest 50 or Systen (Evorel) 50

OBJECTIVES

In order to compare the pharmacokinetics of two transdermal estrogen replacement therapy (ERT) systems designed to release 50 micrograms 17 beta-estradiol/day, two studies were performed in healthy postmenopausal volunteers.

METHODS

Both studies had a cross-over design and incorporated a 1-week wash-out period between treatments. In the first study, Menorest 50 and Systen 50 (Evorel 50) were compared over four days of application in 30 women. In the second, 13 women wore each of the two systems for a total of 12 days each (three patches each for 4 days), and comparison was made during the third patch period (steady state, between days 8 and 12). Plasma 17 beta-estradiol levels were assayed using specific direct radioimmunoassays, and pharmacokinetic parameters were calculated by standard methods. All the samples of the first study were re-analysed using a different radioimmunoassay and the results of both assays were compared.

RESULTS

In both studies, plasma 17 beta-estradiol levels rose at a comparable rate and reached similar peak levels with each of the two formulations. Levels then remained relatively constant throughout both evaluation periods with Menorest 50, but began to decline after 12 hours in the first study and after 30 h under steady state conditions in the second study with Systen 50. The difference between the two products was statistically significant in both studies. Analysis of pharmacokinetic parameters confirmed the greater bioavailability of Menorest 50. In addition, 17 beta-estradiol levels remained within the suggested therapeutic ranges for relief of acute symptoms and protection against osteoporosis for longer periods of time with Menorest 50 than with Systen 50.

CONCLUSION

Since the acute efficacy, long-term protective effects, side effects and risks associated with ERT may depend on critical threshold plasma levels, much attention should be paid to the pharmacokinetic profiles of different formulations. The comparison of these two different radioimmunoassays demonstrates the comparability of their results.

Efficacy and tolerability of Menorest 50 compared with Estraderm TTS 50 in the treatment of postmenopausal symptoms. A randomized, multicenter, parallel group study

Two-hundred and five (205) menopausal women with moderate to severe vasomotor symptoms, aged 39-64 years, were randomized from 20 clinical centers. After a 4-week treatment-free period, each woman received a cyclical regimen (25 days of a 4-week cycle) of Menorest 50, a new matrix-type transdermal estradiol system or Estraderm TTS 50, a marketed reservoir-type transdermal estradiol system twice weekly for 12 weeks. An oral progestin was also given for 10 days each cycle. The objectives were to compare local and systemic tolerability and efficacy in the treatment of menopausal symptoms. One-hundred and ninety-four [194] patients (96 and 98 patients in the Menorest 50 and the reservoir transdermal patch groups, respectively) were considered in the intent-to-treat population and 204 (102 in each group) in the safety population. The two treatment groups were comparable with regard to the demographic data and menopausal status. The primary efficacy criteria were the comparison between Menorest 50 and the reservoir transdermal patch in erythema and pruritus at application sites and the difference between the treatment groups in the mean number of hot flushes per day at week 12, adjusted for baseline. A statistically significant reduction in the mean number of hot flushes was observed in each group compared with baseline, with a decrease from 6.5 at baseline to 0.3 at 12 weeks and 6.4 to 0.4 in the Menorest 50 and reservoir transdermal patch groups respectively; there was no statistically significant difference between the two groups during the 12-week treatment. The severity score of menopausal symptoms was also dramatically improved in each of the two treatment groups. There were no statistically significant differences in the mean plasma estradiol concentrations and mean estradiol to estrone ratio (> 1.0) in both groups after 10 weeks of therapy. A similar number of adverse events was observed in both groups. Menorest 50 showed better local tolerability than the reservoir transdermal patch with a lower incidence of topical adverse events, erythema and pruritus. In summary, Menorest 50 was as effective as the reservoir transdermal patch in reducing the mean number of hot flushes, and improving the severity of other menopausal symptoms, including vasomotor, psychiatric and urogenital symptoms.

The importance of bone biopsy in managing renal osteodystrophy

A case is presented in which bone biopsy results helped to resolve not only difficult issues in the clinical management of the patient's renal osteodystrophy but also disruptive psychosocial problems surrounding her clinical course. The outcome was a satisfactory resolution based on rational medical treatment and directed supportive care. The presentation highlights important principles in the procurement, processing, and interpretation of the bone biopsy, while also addressing the importance of accurate diagnosis in facilitating the overall long-term management by the entire renal team.