Poverty is not the main obstacle for quality cancer care in diagnosed cases: Experience of 520 cases from Bangladesh

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Background: Cancer management is expensive everywhere. In the developing countries poverty is always blamed for as to be the main obstacle for quality cancer care. According to WHO report (globocan) 1.295 to 1.36 million people in Bangladesh suffer from cancer. Our health care service is not extensive to diagnose all these cases. A number of diagnosed cases do not get standard specific treatment of cancer. The objective of the study is to find out the main possible reason behind it. Methods: We made a prospective analysis of pre-diagnosis and post-diagnosis expenses using hospital documents & taken interview with specific questionnaire form of 520 cases regardless of age, indication and management who are treated from January 2002 to December 2005 in NICRH, City General Hospital & Bangladesh Medical College Hospital. We calculated the total expenses incurred to each case before specific diagnosis (EBD). These include all investigations, and non-specific treatment costs from the onset of symptoms up to the specific diagnosis. We have estimated the total expenses after diagnosis (EAD). This includes planned specific cancer management according to diagnosis. We made a ratio in percent between them (EBD/EAD×100). Results: 219 cases (42%) spent = 100% of EAD before diagnosis. 94 cases (18%) spent = 200% of EAD before diagnosis. The more this ratio, less the quality of management they could afford. Among them 349 cases (67%) failed to complete planned management, 57 cases (11%) failed to receive any planned management. Only 114 cases (22%) completed their planned management. Queries revealed that 78% patients who failed to complete planned management is due to their financial exhaustion for high pre-diagnostic expenses. Conclusions: We conclude that poverty is not the main obstacle for quality cancer care in diagnosed cases of Bangladesh. High unnecessary pre-diagnostic expenses, which result in financial exhaustion, is one of the major obstacles for quality cancer care. Further study is required to determine how to reduce the redundant pre-diagnostic expenses & find out other removable factors for quality cancer care in developing countries like Bangladesh.

No significant financial relationships to disclose.

Implication of human epidermal growth factor receptor-2 (HER-2) over expression in treatment of breast cancer in developing countries—report on 250 cases from Bangladesh

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Background: Carcinoma breast is the second most common malignancy in Bangladeshi women. Though HER-2 over expression has profound effect on prognosis of breast cancer, no published data is available about this among Bangladeshi patients. Our aim in this study was to see HER-2 status in Bangladeshi patients, and their relation with other prognostic parameters. Implication of this molecular marker in management of breast cancer in poor country like ours remains controversial, keeping in mind the exorbitantly high cost of Trastuzumab. Methods: This prospective study was conducted in the department of Oncology at Bangladesh Medical College Hospital, National Institute of Cancer Research and Hospital and Ahsania Mission Cancer Hospital Bangladesh, from January 2003 to December 2006. Total 250 women with breast carcinoma were enrolled; biopsy specimens were tested by immunohistochemistry to detect HER-2 status. For recommending treatment with Trastuzumab, patients with 3+ immunohistochemistry results were considered HER-2 positive. Fluorescent In Situ Hybridization (FISH) testing facility was not available. These findings were correlated with age, ER/PR and nodal status. The practical application of marker in terms of use of Trastuzumab was analyzed. Results: Age of patients ranged from 19.75 years to 72 years, mean age was 49.75 years. HER-2 was over expressed in 38.4 % (96) cases and their mean age was 42.92 years compared to 47.61 years in HER-2 negative cases. HER-2 positive cases tended to have higher rates of lymph node metastases (44 out of 96) compared to HER-2 negative (46 out of 154) cases (45.8 % vs 29.87 %). ER/PR was positive in 64 % cases. HER-2 over expression was inversely related to ER / PR expression. Of the HER-2 positive cases, 11.45 % (11 out of 96) afforded treatment with Trastuzumab. Conclusions: HER-2 is over expressed in almost 38 % of breast carcinoma patients in Bangladesh. This expression is associated with relatively young age, lymph node metastasis and lack of ER / PR expression. Only 11.45 % of patients with HER-2 over expression afforded Trastuzumab though 38 % of cases over expressed HER-2.

No significant financial relationships to disclose.

Neoadjuvant chemotherapy with docetaxel and cisplatin followed by concomitant chemoradiotherapy (CT-RT) in the management of locally advanced laryngeal carcinoma

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Background: Neoadjuvant chemotherapy has been used effectively in the treatment of locally advanced head and neck cancers. We conducted a study to evaluate the efficacy and adverse events associated with neoadjuvant chemotherapy schedule comprising of docetaxel and cisplatin followed by concomitant CT-RT from July 2004 to June 2006. Methods: 25 patients with locally advanced supraglottic laryngeal cancer were enrolled to receive docetaxel 75 mg/m2 and cisplatin 75 mg/m2 every 3 weekly for 3 cycles followed by one cycle of concomitant external beam radiotherapy (6000 cGy) and docetaxel 75 mg/m2+cisplatin 75 mg/m2 on day 7 of radiotherapy. All patients after completion of neoadjuvant chemotherapy were evaluated by CT scan and direct laryngoscopy and biopsy from any residual disease. All patients were followed up every month up to disease progression. Follow-up was done by physical examination and indirect laryngoscopy and by 3 monthly CT scan. Adverse events were treated mostly on outpatient basis. Results: Out of 25 patients, 9 had residual disease after completion of treatment and 2 had a disease relapse within 5 months of disease completion. The remaining 14 patients were disease free from a duration of 6 to14 months follow-up period. Median progress free survival had not been reached. 9 (36%) patients had severe mucositis and neutropenia while receiving concomitant CT-RT. 6 (24%) patients had grade III mucositis and rest 3 (12%) patients had grade II mucositis and all the 9 (36%) patients had grade III neutropenia. All of them were treated with G-CSF and prophylactic antibiotics. All the rest had grade I and grade II mucositis and neutropenia Conclusions: In our experience, neoadjuvant chemotherapy with docetaxel and cisplatin (3 cycles) followed by 1 cycle of concomitant CT-RT may be a good choice in treating locally advanced supraglottic laryngeal cancer. The toxicity profile was also manageable.

No significant financial relationships to disclose.

Asynchronous administration of xenon and hypothermia significantly reduces brain infarction in the neonatal rat

BACKGROUND

Neonatal asphyxia causes long-term neurological and behavioural impairment in the developing brain. Concurrent administration of xenon and hypothermia synergistically reduces long-term damage in a rat model of neonatal asphyxia. This study sought to investigate whether asynchronous administration of xenon and hypothermia is capable of combining synergistically to provide neuroprotection.

METHODS

Seven-day-old rats were subjected to right common carotid artery occlusion followed by 90 min hypoxia with 8% oxygen. After a 1 h recovery period, rats received asynchronous administration of mild hypothermia (35 degrees C) and xenon (20%) with a 1 or 5 h gap between interventions, xenon (20%) alone, or mild hypothermia (35 degrees C) alone. Infarct volume in the brain was measured 4 days after injury.

RESULTS

Administration of hypothermia or xenon alone, 1 and 6 h after the hypoxic ischaemic insult, respectively, provided no neuroprotection. Asynchronous administration of xenon and hypothermia at a 1 h interval produced a significant reduction in infarct volume [93 (7) vs 74 (8); P < 0.05]. Reduction in infarct volume was also present when hypothermia and xenon were asynchronously administered with an intervening gap of 5 h [97 (5) vs 83 (3); P < 0.05].

CONCLUSIONS

This finding provides a rationale for investigating the combined use of hypothermia and xenon in a progressive manner for the management of neonatal asphyxia. Thus, hypothermia can be administrated at the site of delivery and xenon can be administered later.

Prenatal exposure to thalidomide, altered vasculogenesis, and CNS malformations

Malformations of cortical development (MCD) result from abnormal neuronal positioning during corticogenesis. MCD are believed to be the morphological and perhaps physiological bases of several neurological diseases, spanning from mental retardation to autism and epilepsy. In view of the fact that during development, an appropriate blood supply is necessary to drive organogenesis in other organs, we hypothesized that vasculogenesis plays an important role in brain development and that E15 exposure in rats to the angiogenesis inhibitor thalidomide would cause postnatal MCD. Our results demonstrate that thalidomide inhibits angiogenesis in vitro at concentrations that result in significant morphological alterations in cortical and hippocampal regions of rats prenatally exposed to this vasculotoxin. Abnormal neuronal development was associated with vascular malformations and a leaky blood-brain barrier. Protein extravasation and uptake of fluorescent albumin by neurons, but not glia, was commonly associated with abnormal cortical development. Neuronal hyperexcitability was also a hallmark of these abnormal cortical regions. Our results suggest that prenatal vasculogenesis is required to support normal neuronal migration and maturation. Altering this process leads to failure of normal cerebrovascular development and may have a profound implication for CNS maturation.

An evaluation of door to needle time (DNT) of thrombolytic therapy following acute myocardial infarction in three large tertiary referral hospitals in Dhaka City

This study was conducted in three tertiary hospitals in Dhaka city at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka Medical College Hospital (DMCH) and National Institute of Cardiovascular Disease (NICVD) as a part of Inter-Heart Study. Secondary data was obtained from the standard questionnaires to determine door to needle time (DNT) following thrombolytic therapy in patients with Acute Myocardial Infarction (AMI) in coronary care units at three large tertiary referral hospitals in Dhaka city. Of total 192 patients studied in three centres, 156 (81.2%) received thrombolytic therapy. In BSMMU, 33 out of 45 (73.33%) patients received thrombolysis. Mean DNT was 147 minutes. Eighteen (55%) patients received thrombolysis within 90 minutes and 9 patients (27%) received with in 91-180 minutes, 6 patients (18%) received thrombolysis after 180 minutes. In DMCH, 44 out of 57 patients (77.1%) received thrombolysis. Mean DNT was 210 minutes. Five patients (11%) received within 90 minutes, 19 (43%) received thrombolysis between 91 to 180 minutes and 20 patients (46%) received thrombolysis outside the range of 180 minutes. In the NICVD, 79 out of total 90 (87.7%) patients received thrombolysis. Mean DTN was 64 minutes. Sixty seven (82%) patients received therapy within 90 minutes, 6 patients (9%) received between thrombolysis 91-180 minutes and 6 (9%) patients received after 180 minutes of reaching hospital. Inspite of overall improvement in the management of patients with AMI in coronary care units of major teaching hospitals, there seem to remain certain difficulty in our system which causes delay in thrombolysing patients with AMI. In this study, the mean DNT for thrombolysis was quickest (64 minutes) at NICVD and slowest (210 minutes) at DMCH. Although the study was conducted almost four years ago, it gives some insight regarding strength and weaknesses in the infrastructure of public sector hospitals in our country.

Regulation of Osteoblast Gene Expression and Phenotype by Polylactide-fatty Acid Surfaces

Cell function is influenced by surface structure and molecules. Molecules that enhance cellular differentiation can be applied to tissue scaffold surfaces to stimulate endogenous tissue regeneration. The application of this approach to bone implants yields surfaces coated with factors (proteins, peptides, etc...) that promote the differentiation of osteoblasts, the cells that make bone. Increased bone formation leads to increased healing and union of the implant with endogenous bone. To obtain better control over surface coating we developed PLLA copolymers with allyl (PLLA-co-DAG) and 3-hydroxypropyl (PLLA-co-HP) side chains to which we can attach functional groups. Given the potential of fatty acids being able to incorporate into lipid bilayers and/or influence gene expression, we grafted different fatty acid side chains to PLLA-co-HP by esterifying the corresponding fatty acids with the PLLA-co-HP 3-hydroxypropyl side chains. The effects of the polymer modifications on osteoblasts were then evaluated. While cellular morphology differed between surface coatings, they did not reflect changes in cellular phenotype. Changes in gene expression were most evident with arachidonate and 3-hydroxypropyl side-chains which exhibited osteoblast differentiating capabilities. Linoleate, myristate, oleate, and stearate ester side-chains did not have a significant influence on osteoblast phenotype. Growth characteristics of osteoblasts did not differ between the fatty acid copolymer films, although cells grown on PLLA-co-HP exhibited a trend toward increased growth. Taken together our findings demonstrate that surface fatty acid composition can impact osteoblast phenotype.

Isoflurane exerts antinociceptive and hypnotic properties at all ages in Fischer rats

BACKGROUND

Some anaesthetic agents exhibit an age-dependent analgesic effect, for example nitrous oxide, which is ineffective in newborn rats. We investigated whether a similar time dependency existed for the responses to the volatile anaesthetic isoflurane.

METHODS

The analgesic and hypnotic properties of isoflurane at various ages was assessed using four cohorts of Fischer rats aged approximately 7, 16, and 28 days and adults (11-12 weeks old). Intraplantar administration of formalin mimicked inflammatory pain, and its effects were assessed using immunohistochemical (c-Fos staining) and behavioural paradigms. The hypnotic properties of isoflurane were assessed using loss of righting reflex.

RESULTS

Formalin administration produced a typical nociceptive response observed both behaviourally and immunohistochemically in all age groups; these nociceptive responses were significantly attenuated by isoflurane 0.5% at each age (P<0.05). Interestingly 7-day-old animals showed a significantly more potent hypnotic response than older animals (P<0.01): with adult rats being most resistant to isoflurane induced hypnosis (P<0.05).

CONCLUSION

In contrast to nitrous oxide, isoflurane is an effective antinociceptive agent in neonatal rats. If the data can be extrapolated to clinical scenarios these results suggest that isoflurane may be analgesic in newborns as well as adult humans. In addition, isoflurane is a potent hypnotic, especially in the very young, which is in contrast to the neonate's relative resistance to anaesthesia as assessed by minimum alveolar concentration.

Hepatocyte growth factor (HGF) adsorption kinetics and enhancement of osteoblast differentiation on hydroxyapatite surfaces

Hepatocyte growth factor (HGF) is a growth factor that promotes angiogenesis (tissue vascularization), cell motility, and cell differentiation, making it a potentially beneficial coating for bone implants. However, very little is known about maximizing HGF attachment to surfaces of tissue-engineered scaffolds. Here, we examine methods and kinetics of HGF adsorption onto a dense hydroxyapatite (HA) surface (used in bone implants) and determine the influence of HGF coating on osteoblast phenotype/differentiation. We demonstrate that incubating HA with HGF in solution (and not allowing the solution to dry) resulted in maximal surface adsorption that was not enhanced by extending incubation time beyond 2 days. Daily shaking of the coated HA surface did not remove adsorbed HGF. To further examine the effect of HA on osteoblast phenotype, MC3T3-E1 preosteoblasts were seeded onto HA or HGF-HA surfaces. Gene expression analyses indicate that HGF coating enhanced osteoblast differentiation as demonstrated by increased runx2 (a transcription factor important for osteoblast lineage and differentiation), alkaline phosphatase (marker of mid stage differentiation) and osteocalcin (marker of late stage differentiation) mRNA levels. Taken together, our results demonstrate that HGF can serve as an excellent bone implant coating based on its ability to readily adsorb to HA surfaces, maintain integrity over time, and enhance osteoblast differentiation.

Late effect of prenatal irradiation on the hippocampal histology and brain weight in adult mice

We studied the changes in the brain weight and hippocampal histology in adult offspring exposed to 0.25-1.5 Gy of 60Co gamma radiations during day 14 or 17 of gestation. Irradiation with 0.5-1.5 Gy produced a significant decrease in brain weight of the offspring at 6 and 12 months of age. Exposure to 1 Gy at day 14 or 17 of gestation resulted in significant decrease in the number of neurons in the CA3 and CA4 regions of hippocampus of 200 microm length, while 1.5 Gy significantly affected CA1 region also. The fetal period (13-18 days of gestation) of mouse development is an active phase of brain development involving proliferation, migration and differentiation of cerebral cortex and associated structures. The present results show that exposure at this period of mouse development to moderate doses of gamma radiation can induce permanent deficits in the brain histology, which can adversely affect the learning and memory in adults.

Evaluation of biocompatibility of mineral trioxide aggregate with an improved rabbit ear chamber

In the present study, the biocompatibility of mineral trioxide aggregate (MTA) to the revascularization of the connective tissues was evaluated by using the improved rabbit ear chamber, in vivo. Twenty improved rabbit ear chamber was prepared from 12 male albino-rabbit by using a well through which a material could be introduced into the living vascular tissue. Ten chambers were provided for MTA, and the remaining 10 chambers were used for a calcium hydroxide-containing root canal sealer (Sealapex), as a comparator. A volume of about 1.5 mm(3) of the materials were inserted into the chamber and the interaction between the vascular tissue and materials was observed by using a biomicroscope immediately after application, at 1, 3, 5.5, 8, 24, 48, 72 h, and once a week up to 4 weeks. The results revealed that revascularization of connective tissue took place with complete recovery of microcirculation within 4 weeks in both MTA and Sealapex. However, the precipitate-barrier and brown zone around periphery of Sealapex was not observed in MTA treated samples. It can be concluded that MTA is biocompatible and does not produce any adverse site effect on microcirculation of the connective tissue.

A model of dynamic sacro–iliac joint instability from malrecruitment of gluteus maximus and biceps femoris muscles resulting in low back pain

The objective of this work is to propose a biomechanical model of sacro-iliac joint dysfunction as a cause of low back pain. Sacro-iliac joint is known to be a source of low back pain. We also know that it is a very stable joint with little mobility. Surrounding lower limb and back muscles contribute a major part of this stability. Gait analysis studies have revealed an orderly sequence of muscle activation when we walk - that contributes to efficient stabilisation of the joint and effective weight transfer to the lower limb. Gluteus maximus fibres-lying almost perpendicular to the joint surfaces are ideally oriented for this purpose. Biceps femoris is another important muscle that can also influence joint stability by its proximal attachment to sacrotuberous ligament. Altered pattern of muscle recruitment has been observed in patients with low back pain. But we do not know the exact cause-effect relationship. Because of its position as a key linkage in transmission of weight from the upper limbs to the lower, poor joint stability could have major consequences on weight bearing. It is proposed that sacro-iliac joint dysfunction can result from malrecruitment of gluteus maximus motor units during weight bearing. This results in compensatory biceps over activation. The resulting soft tissue strain and joint instability may manifest itself in low back pain. If our hypothesis holds true, it may have positive implications for patients with sacro-iliac joint dysfunction - who could be offered a definite diagnosis and targeted physiotherapy. It may be possible to identify patients early in a primary care setting and offer direct physio referral. They could benefit from exercises to improve strengthening and recruitment of the affected muscles.

Determination of the enantiomeric purity of the phytoalexins spirobrassinins by 1H NMR using chiral solvation

A simple and inexpensive method for enantiomeric discrimination of the phytoalexins spirobrassinin (1), 1-methoxyspirobrassinin (2) and synthetic analog 1-methylspirobrassinin (6) using the chiral solvating agent 2,2,2-trifluoro-1-(9-anthryl)ethanol in C(6)D(6) is described. Using this method the enantiomeric composition of each sample can be determined accurately by (1)H NMR and the compounds can be recovered readily by chromatography.

Yield Loss Caused by Meloidogyne graminicola on Lowland Rainfed Rice in Bangladesh

The impact of Meloidogyne graminicola on growth and yield of lowland rainfed rice was assessed with and without carbofuran in a rice-wheat rotation area of northwestern Bangladesh. The experiment was conducted on farmer fields and at a research station, with experimental plots arranged in a randomized complete block design. Prior to transplanting, rice seedling height and dry weight were greater (P </= 0.05) and soil levels of M. graminicola were lower (P </= 0.05) in the treated seedbed plots compared to the nontreated control plots. Nematicide application to the field at transplanting had a greater effect (P </= 0.05) on mid-season plant growth than did nematicide application to the seedbed at sowing, and rice yield increased by 1.0 t/ha where carbofuran was applied to the seedbed and field-both at the research station (P </= 0.05) and on farmer fields (P </= 0.10)- compared to a nontreated control. This is the first report of a negative impact of M. graminicola on growth and yield of lowland rainfed rice in production fields in Bangladesh.

Relationship between expression of multiple drug resistance proteins and p53 tumor suppressor gene proteins in human brain astrocytes

Multiple drug resistance occurs when cells fail to respond to chemotherapy. Although it has been established that the drug efflux protein P-glycoprotein protects the brain from xenobiotics, the mechanisms involved in the regulation of expression of multiple drug resistance genes and proteins are not fully understood. Re-entry into the cell cycle and integrity of the p53 signaling pathway have been proposed as triggers of multiple drug resistance expression in tumor cells. Whether this regulation occurs in non-tumor CNS tissue is not known. Since multiple drug resistance overexpression has been reported in glia and blood vessels from epileptic brain, we investigated the level of expression of multidrug resistance protein, multidrug resistance-associated proteins and lung resistance protein in endothelial cells and astrocytes isolated from epileptic patients or studied in situ in surgical tissue samples by double label immunocytochemistry. Reverse transcriptase-polymerase chain reaction and Western blot analyses revealed that multiple drug resistance, multidrug resistance protein, and lung resistance protein are expressed in these cells. Given that lung resistance proteins have been reported to be preferentially expressed by tumors, we investigated expression of tumor suppressor genes in epileptic cortices. The pro-apoptotic proteins p53 and p21 could not be detected in "epileptic" astrocytes, while endothelial cells from the same samples readily expressed these proteins, as did normal brain astroglia and normal endothelial cells. Other apoptotic markers were also absent in epileptic glia. Our results suggest a possible link between loss of p53 function and expression of multiple drug resistance in non-tumor CNS cells.

Demand-based water options for arsenic mitigation: an experience from rural Bangladesh

A supply of safe drinking water is a recognized global concern. The arsenic contamination of groundwater in Bangladesh and other countries has furthered this concern. Lack of appropriate water options is one of the main barriers to the supply of safe drinking water for 30-60 million people who are exposed to the risk of drinking arsenic-contaminated water in Bangladesh. This paper describes the experience from a water supply programme for arsenic mitigation based on demand and participation of 30,000 rural people in Srinagar, a subdistrict of Bangladesh. About 85% of the 912 tubewell water samples tested had an arsenic content higher than 0.05 mg/l. The project promoted 11 options including groundwater, surface-water and rainwater-harvesting household-based options as well as community managed technologies. Most people, particularly women, wanted piped water, and hand-operated deep tubewells were also requested. Four cluster-based motorized piped water systems, 20 home-based arsenic-removal options (two types) and an arsenic-removal filter plant were installed. The public contributed about 49, 25 and 20% of the installation costs of piped water, home-based options and filter options, respectively, and 100% of all operation and maintenance costs. The household options and filter plant were abandoned within a few weeks. Reportedly, those options required too much attention, discharged small volumes of water at low rates, were difficult to maintain, and discharged poor-quality water. The proportion of families (54%) that drank arsenic-contaminated water during the final survey was significantly lower than in the baseline survey (87%). For arsenic-affected areas, it is recommended that a cluster-based piped water system be given proper consideration when selecting appropriate water options rather than household-based options or the development of new low-cost options.

Improvement in pulsed wave Doppler echocardiographic assessment of pulmonary artery pressure

Non invasive estimation of pulmonary artery pressure (PAP) is of paramount importance in various form of cardiac, respiratory and intensive care medicine practice. Using pressure gradient between different chambers enables a reliable estimation of PAP and are being largely practiced. In absence of these pressure gradient, various time interval or the ratios of pulmonary blood flow velocity curve (PBFVC) in pulsed wave doppler echocardiography (PWDE) can predict the PAP. But there is lack of general agreement as which parameter should be used. We hypothesized that using separate time interval or their ratios of PBFVC for different group of patient may improve the PWDE prediction of PAP. Forty-six consecutive patients with different cardiac diseases and 20 consecutive control persons underwent PWD echocardiographic examination. Pulmonary blood flow velocity curve derived time intervals--the time intervals--time to peak velocity (TPV), Pre-ejection period (PEP) and right ventricular ejection time (RVET) and their ratios were measured. The Doppler derived measurements were compared with cardiac catheterization (CC) measured PAP in 46 patients in whom CC were done. PBFVC derived time interval TPV and the ratio PEP/TPV correlated well with CC measured systolic PAP (r=-0.78 and r=0.77 respectively). For congenital left to right shunt disease the ratio PEP/TPV improved the prediction (r=-0.87) while the same measure showed weak correlation in patients with left sided heart disease. Only TPV could predict mean PAP in patients with left sided heart disease (r=-0.60). We concluded that the use of separate PBFVC derived time interval or their ratio from PWDE may improve the prediction of PAP with different pathological group of disease.

Dose proportionality study of four doses of an estradiol transdermal system, Estradot®

OBJECTIVES

To establish dose proportionality among four doses of a new estradiol transdermal system (ETS), Estradot, in healthy postmenopausal women and to evaluate the wear and irritation properties of the ETS.

METHODS

In an open label, single-dose, randomized, four-period crossover study, healthy postmenopausal women, age range 44-64 years, wore four different sizes of Estradot, 2.5, 3.75, 5.0 and 10.0 cm(2) that were expected to release estradiol at 0.025, 0.0375, 0.05 and 0.10 mg/day, respectively. Each patch was worn for 84 h with a 7-day washout period between treatments. Blood samples were drawn prior to medication, then at various time points following patch application. Serum concentrations of estradiol and estrone were determined by validated gas chromatography/mass spectrometry (GS/MS) methods. Skin irritation, (erythema and edema), patch adherence and local skin reaction were assessed and recorded following patch removal. After removal, the patches were assayed for residual estradiol to estimate the apparent dose delivered.

RESULTS

The baseline-corrected, mean maximum serum estradiol concentrations (C(max)) for the 2.5, 3.75, 5.0 and 10.0 cm(2) patches were 24.0, 34.8, 50.1 and 96.0 pg/ml, respectively, and for estrone were 10.5, 15.2, 21.8 and 41.0 pg/ml, respectively. The four Estradot patches adhered well during the study. No significant skin irritation was observed with any of the four treatments.

CONCLUSIONS

The results indicate a dose proportional relationship of increased serum concentrations of estradiol with increasing size of the Estradot patches. The four doses of Estradot demonstrated good systemic and local skin tolerability.

Comparative bioequivalence studies with Estradot® and Menorest® transdermal systems

OBJECTIVES

To compare the relative bioavailability of Estradot, a small size, new generation estradiol transdermal system (ETS) to Menorest, in healthy postmenopausal women.

METHODS

In two open-label, single center, randomized, crossover, bioequivalence studies, healthy postmenopausal women aged 40-65 years received treatment with all the test regimens. In Study 1 (single-dose study), patients wore 5 cm(2) (50 microg/day), 10 cm(2) (100 microg/day) Estradot and 29 cm(2) (100 microg/day) Menorest for 84 h. In Study 2 (multiple-dose study), patients wore a regimen of four consecutive treatments with a 5 cm(2) (50 microg/day) new generation patch, Estradot and a 14.5 cm(2) (50 microg/day) patch, Menorest. Blood samples were drawn at various time-points in both studies. Estradiol and estrone serum levels were determined by gas chromatography/mass spectrometry or radioimmunoassay methods. Skin irritation (erythema and edema), patch adherence and local skin reaction were assessed following patch removal.

RESULTS

In Study 1, baseline-uncorrected C(max) for estradiol for Estradot 50 and 100 microg/day and Menorest 100 microg/day was 54.8, 106.2 and 101.6 pg/ml, respectively, and C(max) for estrone was 75.6, 97.0 and 98.3 pg/ml, respectively. In Study 2, the baseline-uncorrected mean maximum serum concentration (C(max)) for estradiol for Estradot 50 microg/day and Menorest 50 microg/day patches was 56.7 and 52.7 pg/ml, respectively, and C(max) for estrone was 41.7 and 41.3 pg/ml, respectively. No significant skin irritation was observed in either study, but Estradot caused less skin irritation than Menorest.

CONCLUSIONS

Estradot produced comparable serum concentrations of estradiol and estrone and caused less skin irritation than Menorest.