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Scopolamine increases vagal tone and vagal reflexes in patients after myocardial infarction.

OBJECTIVES: The goal of this study was to assess the hypothesis that transdermal scopolamine would increase vagal activity in patients after myocardial infarction. BACKGROUND: In postmyocardial infarction patients, low heart rate variability and reduced baroreceptor reflex sensitivity are associated with increased mortality. Accordingly, there is an increasing interest in a mechanism for shifting the sympathovagal balance toward vagal dominance. METHODS: The effects of transdermal administration of scopolamine on heart rate variability and baroreceptor reflex sensitivity were assessed in 20 patients (mean age 59 +/- 11 years) by pharmacologic washout 14 +/- 3 days after myocardial infarction. Heart rate variability and baroreceptor reflex sensitivity were measured 24 h after application of the scopolamine patch and compared with the values measured before scopolamine and after application of a placebo patch. The following variables were derived from a 15-min electrocardiographic recording: the mean RR interval and its standard deviation, the mean square successive difference, the percent of intervals differing > 50 ms from the preceding RR interval and the low and high frequency areas resulting from power spectral analysis. RESULTS: The placebo patch had no effect on the variables measured. Scopolamine increased both heart rate variability and baroreceptor reflex sensitivity significantly. Specifically, the mean RR interval and its standard deviation increased by 7.1% (p = 0.01) and 25% (p = 0.004), respectively. The mean square successive difference increased by 38% (p = 0.0003) and the percent of intervals differing > 50 ms from the preceding interval by 100% (p = 0.001). The ratio of low to high frequency areas of the power spectrum decreased by 24% (p = 0.02), and baroreceptor reflex sensitivity increased by 42% (p = 0.0006). These effects were also evident in patients with very low initial values. Side effects were minimal. CONCLUSIONS: Transdermal scopolamine increased measures of heart rate variability and baroreceptor reflex sensitivity in patients with a recent myocardial infarction toward values associated with a better prognosis. Pharmacologic modulation of the autonomic balance by scopolamine or related drugs deserves evaluation as a new and promising approach to reduce risk after myocardial infarction.

Administration, Cutaneous↗

[Transcutaneous transport of trinitrin in children after application of nitroglycerin patches].

Plasma levels of nitroglycerin were measured 13 to 24 hours after the application of nitroglycerin stamps in 7 children aged from 1 month to 7 years and suffering from heart failure. The plasma levels varied considerably from one patient to another, confirming that the bioavailability of transdermal nitroglycerin is extremely variable in children. Only 3 patients had a nitraemia higher than 1 ng/ml, a figure compatible with a haemodynamic effect of the drug. No side-effect associated with the nitroglycerin stamps was observed. The dosage we use (a quarter of a stamp for 5 kg bodyweight) seems to be adequate at the beginning of treatment, to be progressively increased according to the way the drug is tolerated.

Administration, Cutaneous↗

Controlled transdermal delivery of propranolol using HPMC matrices: design and in-vitro and in-vivo evaluation.

To improve bioavailability and achieve a smoother plasma-concentration profile as compared with oral administration, a matrix-dispersion-type transdermal delivery system was designed and developed for propranolol using different ratios of hydroxypropylmethylcellulose (HPMC) K4M, K15M and K100M. Formulations were evaluated for in-vitro dissolution characteristics using a Cygnus' sandwich-patch holder. Drug release followed Higuchi rather than zero-order or first-order kinetics. In-vivo evaluation was carried out on healthy volunteers (21+/-1.41 years; 60.89+/-5.35 kg) following the balanced incomplete block design. The dissolution rate constant (k) and data generated from plasma and urine (Cmax, maximum plasma concentration; t(max), time to reach peak plasma concentration; AUC, area under the curve; k(e), elimination rate constant; t1/2e, elimination half-life; k(a), absorption rate constant; t1/2a, absorption half-life) were evaluated statistically by two-way analysis of variance. Statistically excellent correlation was found between the percentage of drug absorbed and Cmax, AUC0-24 and AUC0-infinity. A highly significant difference (P < 0.001) was observed when Cmax and AUC0-infinity, generated from plasma and urine were compared, but k(e), t1/2e, k(a) and t1/2a did not differ significantly (P > 0.1). We conclude that urinary excretion data may be used as a simpler alternative to blood level data in studying the kinetics of absorption and deriving the absorption parameters.

Administration, Cutaneous↗

Nicotine: therapeutic potential for the treatment of ulcerative colitis.

Ulcerative colitis (UC) is predominantly a disease of non-smokers, and nicotine may be the agent responsible for this association. Transdermal nicotine has been shown to improve disease activity and sigmoidoscopic appearance in the active disease but in one study had no effect on maintenance of remission. Since side-effects with nicotine patches occur in up to two thirds of patients, attempts to reduce systemic levels and improve drug tolerance have been developed with colonic delivery systems of nicotine. Preliminary observations with nicotine enemas in UC have shown clinical benefit, but controlled trials are needed. Mechanisms responsible for the association of smoking with colitis and for the therapeutic effect of nicotine remain an enigma; possibilities include: modulation of the immune response, alterations of colonic mucus and eicosanoid production, changes in rectal blood flow, decreased intestinal permeability and the release of endogenous glucocorticoids. With current treatment for UC limited to corticosteroids and formulations of 5-aminosalicylic acid, alternative treatments are required and nicotine may fulfil this role.

Journal Article↗

Effect of acute transdermal estrogen administration on basal, mental stress and cold pressor-induced sympathetic responses in postmenopausal women.

Administration of estrogen has vascular effects through poorly defined mechanisms that may include sympathetic withdrawal. To define the effects of acute estrogen administration on sympathetic responses, nineteen healthy postmenopausal women (age 54+/-2 years) were studied after application of a placebo or estrogen patch for 36 hours, in random order. A p-value, adjusted for multiple comparisons, of <0.017 was used to determine statistical significance. Heart rate, blood pressure, and norepinephrine spillover were measured at rest, during mental stress (Stroop test), and during a cold pressor test. Estrogen did not attenuate basal or stimulated hemodynamic responses significantly. The increase in mean arterial pressure after the Stroop test (5.9+/-1.2mm/ Hg on placebo vs 6.1+/-1.6mm/Hg on estrogen, p=0.9) and after the cold pressor test (12.6+/-2.4mm/Hg on placebo vs 13.0+/-2.2 mm/Hg on estrogen, p=0.8) did not differ. Basal, mental stress and cold pressor-stimulated norepinephrine spillover were not significantly affected by short-term estrogen administration. Norepinephrine spillover tended to be higher after estrogen (1296.2+/-238 ng/min) than placebo (832.5+/-129 ng/min) (p=0.02) at baseline and after the Stroop test (1881.1+/-330 ng/min vs 1014.6+/-249 ng/min) (p=0.02). Acute transdermal estrogen administration did not attenuate norepinephrine spillover or sympathetically mediated hemodynamic responses.

Administration, Cutaneous↗

Autonomic effects of nicotine patch administration in habitual cigarette smokers: a double-blind, placebo-controlled study using spectral analysis of RR interval and systolic arterial pressure variabilities.

Nicotine patch administration is often used to sustain tobacco abstinence in smoking-cessation programs. There is some concern regarding safety issues, as a consequence of the sympathomimetic action of nicotine. We used spectral analysis of RR interval and (noninvasive) systolic arterial pressure (SAP) beat-by-beat variabilities in a crossover double-blind design to assess the autonomic effects of cigarette smoking, of transdermal nicotine, and of placebo. The study group consisted of 27 heavy smokers (age 43 +/- 2 years). The RR interval and its variability were significantly reduced in the smoking group, as compared with nicotine or placebo groups. The LF component of RR interval variability (in normalized units, nu), and the LF/HF ratio showed greatest values during smoking, as compared with placebo. Values of LF(RR) and LF/HF during nicotine patch treatment were slightly, but not significantly, greater than observed with placebo. No differences were observed in SAP and its variability components. The index alpha (a frequency domain measure of baroreflex gain) was minimal in the smoking period. Habitual cigarette smoking is associated with signs of sympathetic predominance in the autonomic control of the sinoatrial (SA) node. Nicotine patches produce only minor disturbances of autonomic regulation. This corroborates their safe use in smoking-cessation strategies.

Administration, Cutaneous↗

A prospective, randomized, placebo-controlled trial of transdermal glyceryl trinitrate in ERCP: effects on technical success and post-ERCP pancreatitis.

BACKGROUND: Despite the recent improvement in techniques and patient selection, post-ERCP pancreatitis remains the most frequent and dreaded complication of ERCP. Recent studies suggest that pretreatment with glyceryl trinitrate (GTN) may prevent post-ERCP pancreatitis and improve cannulation success. OBJECTIVE: To evaluate the effect of transdermal GTN on ERCP cannulation success and post-ERCP pancreatitis. DESIGN: Prospective, double-blind, placebo-controlled trial. SETTING: Tertiary referral university hospital. PATIENTS: A total of 318 patients (mean age 62 years, 61% women) were randomized to either active (n = 155) or placebo (n = 163) arms. INTERVENTIONS: Active patch (GTN) versus placebo patch. MAIN OUTCOME MEASUREMENTS: Cannulation time and success. Post-ERCP pancreatitis rates. RESULTS: There was no significant difference between the active or placebo arms for the following: successful initial cannulation (96.8% vs 98.8%), deep cannulation (96.1% vs 98.8%), time to successful cannulation, use of guidewire (27% vs 25%) or needle knife (13% vs 13%), and post-ERCP pancreatitis (7.4% of placebo patients and 7.7% active patients). Multivariate analysis identified women, younger patients, pancreatogram, number of attempts on papilla, and poor pancreatic-duct emptying after opacification as risk factors for post-ERCP pancreatitis. Transdermal GTN did not reduce post-ERCP pancreatitis in any of the identified high-risk groups. CONCLUSIONS: Transdermal GTN did not improve the rate of success in ERCP cannulation or prevent post-ERCP pancreatitis in either average or high-risk patient groups.

Administration, Cutaneous↗

Does the type of hormone replacement therapy affect lipoprotein (a), homocysteine, and C-reactive protein levels in postmenopausal women?

BACKGROUND: The results of studies evaluating the effect of hormone replacement therapy (HRT) on the cardiovascular risk raise many controversies. This may be related to both the type of treatment used and the disregard of additional risk factors. OBJECTIVE: The objective of the study was to evaluate the effect of natural estrogens taken transdermally and synthetic estrogens taken orally on the concentrations of lipoprotein (a) [Lp(a)], homocysteine, and C-reactive protein (CRP) in healthy women in the early postmenopausal period. Material The study was conducted on 61 healthy women with average age of 52.3 +/- 4.1 years, in the postmenopausal period, who were randomly assigned to 3 groups depending on the type and route of administration of the products. Group I (n = 24) was administered transdermal estrogens (micronized 17beta-estradiol; Systen, Janssen-Cilag, Switzerland) and progesterone in the second phase of the cycle. Group II (n = 21) was administered oral hormones (Cyclo-Menorette). Group III (n = 16), serving as a control, included women taking placebo in the form of patches. In each group, therapeutic cycles took 22 days and were followed by a treatment-free interval of 7 to 10 days for a 3-month period. RESULTS: After 3 months of treatment, Lp(a) and homocysteine levels were not significantly different from the baseline, irrespective of the route of administration of estrogens or placebo. Both forms of HRT used indicate significant difference in changes of CRP concentration during 3 months of administration (analysis of variance P = .0356). CRP concentration values increased in the group of women using oral HRT from 1.22 to 2.68 mg/L. In the group of women using oral therapy, significantly more cases (61%) of increase in CRP concentration compared with 39% in the transdermal HRT group (chi(2) P = .015) were observed. CONCLUSIONS: On the basis of our observations, it appears that in women in the early postmenopausal stage with normal initial concentrations of Lp(a) and homocystein, the form of therapy used has no influence on values of these parameters. The 2 forms of HRT therapy differ in effect, which is expressed as a change in CRP concentration. A tendency to increase CRP values when using oral HRT is observed, while such an effect is not observed in case of transdermal therapy after 3 months.

Administration, Cutaneous↗

Human skin irritation studies of a lecithin microemulsion gel and of lecithin liposomes.

Soybean lecithin microemulsion gels offer promising features for the possible use as matrices in transdermal therapeutic systems. In order to assess the skin irritancy potential of the gel, acute and cumulative irriation tests were performed in human subjects in vivo using as comparison an unilamellar soybean lecithin liposome preparation and the solvent isopropyl palmitate (IPP). Acute irritation was tested in 151 volunteers in a 48-hour patch test, whereas cumulative irritation was assessed in a 21-day human repeated insult patch test in 20 volunteers. In the acute irritation test, discrete irritation (erythema only) developed with the gel in 2 subjects (1.3%), with the liposomes in 3 subjects (2.0%), and with IPP in 2 subjects (1.3%). For the assessment of cumulative irritation, the IT50 (irritation time of 50% of the test population) was calculated. IT50 was 13 days for the gel, 14 days for the liposomes and 17 days for IPP. This study shows a very low acute and a low cumulative irritancy potential for the soybean lecithin microemulsion gel making it a candidate matrix for transdermal therapeutic systems also under toxicological aspects.

Adolescent↗

Continuous versus cyclical transdermal estrogen replacement therapy in postmenopausal women: influence on climacteric symptoms, body weight and bleeding pattern.

OBJECTIVES: To compare continuous and cyclical transdermal estrogen replacement therapy (ERT) with or without an oral progestogen regarding climacteric symptoms, body weight and bleeding pattern. METHODS: A total of 2459 postmenopausal women were treated for three cycles of 28 days in an open, randomized, parallel group multicenter study. Patients received an estrogen matrix patch (50 micrograms 17/beta-estradiol/day) twice weekly, either continuously (eight patches/cycle) or cyclically (six patches/cycle, i.e. 3 weeks on, 1 week off). A total of 1232 patients were treated continuously and 1227 cyclically. In the study group 1150 patients had an intact uterus (543 in the continuous and 607 in the cyclical treatment arm) and received, in addition to the estrogen patch, an oral progestogen in a transformation dose for 12 days of each cycle. Hysterectomized patients totaling 1309 (689 in the continuous versus 620 in the cyclical group) did not receive progestogen. Of the 2459 patients, 771 (31.4%) participated in a follow-up study with two further treatment cycles, which was offered to the patients at the end of the main study. The main outcome measures were climacteric symptoms, measured at the end of cycles 1-3 by a Visual Analogue Scale at baseline, and body weight measured at baseline at the end of cycles 3 and 5. In addition, the bleeding time per cycle (days) was evaluated in all patients with an intact uterus. RESULTS: Continuous and cyclical transdermal ERT reduced, over three treatment cycles, the average climacteric symptom score by 1.77 and 1.70, respectively. The percentage remission and improvement rates for the ten climacteric symptoms ranged between 69.3 and 88.0% and did not differ between the two groups. In patients with a higher symptom score at baseline, the continuous treatment was slightly more effective. However, this effect was statistically not significant. After three treatment cycles body weight increased in both treatment groups by between 500 and 700 g. Further treatment during the follow-up study induced an additional average weight gain of 200-400 g. These results were not influenced by the addition of an oral progestogen. In patients with an intact uterus, the average bleeding time at the end of the first cycle (5.4 days in the continuous versus 5.3 days in the cyclical group) increased slightly during cycle 2 and returned to baseline values at the end of cycle 3. CONCLUSIONS: Continuous and cyclical transdermal ERT were equally effective in reducing climacteric symptoms. The short term use of five cycles transdermal ERT induced a slight increase in body weight which was independent of the treatment regimen. These results were not influenced by the type and mode of administration of a progestogen. Both ERT regimens were very well tolerated and are suitable alternatives for estrogen replacement therapy of postmenopausal women.

Administration, Cutaneous↗

Efficacy and safety of two different galenic formulations of a transdermal clonidine system in the treatment of hypertension.

The efficacy and safety of two different galenic formulations of transdermal clonidine systems were compared in 905 patients with mild to moderate essential hypertension during a 12 weeks observation period. 449 patients were treated with the matrix controlled clonidine transdermal (C-TD) system and 456 patients with the membrane controlled clonidine system (C-TTS). The mean blood pressure was reduced from 168/102 mmHg to 146/87 mmHg in the C-TD and from 169/102 mmHg to 148/88 mmHg in the C-TTS group. There was no difference in the response rate. The pattern of systemic side-effects appeared to correspond to those seen during oral clonidine treatment but with a lower frequency and intensity. The C-TD patch improved skin tolerability and the drop-out rate due to skin reactions was 2.2 times lower compared with the C-TTS group. Local skin reactions led to withdrawal in 35 of 449 C-TD treated and in 79 of 456 C-TTS treated patients. In conclusion, the improved carrier system for the transdermal clonidine treatment reduced local side-effects which in turn may further enhance acceptability and compliance in treated patients.

Administration, Cutaneous↗

The effect of inhalant anesthetic and body temperature on peri-anesthetic serum concentrations of transdermally administered fentanyl in dogs.

OBJECTIVES: To determine whether moderate hypothermia during anesthesia significantly affects the serum concentration of transdermally delivered fentanyl and whether halothane or isoflurane affect these concentrations. STUDY DESIGN: Randomized cross-over experimental trial. ANIMALS: Six mature, healthy Beagles (three males, three females) weighing 10.6 +/- 0.43 kg. METHODS: A 50-microg hour(-1) fentanyl patch was applied 36 hours prior to anesthesia. Anesthesia was induced at time 0 (t = 0). Each dog received four treatments: isoflurane + normothermia (ISO-NORM), isoflurane + hypothermia (ISO-HYPO), halothane + normothermia (HAL-NORM), and halothane + hypothermia (HAL-HYPO). Dogs were intubated and maintained at 1.5 times MAC. Animals in the hypothermia treatments were cooled to 35 degrees C during anesthesia. Serum fentanyl analysis was performed at -36, -24, -12, 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 18, and 26 hours. Direct arterial blood pressures and arterial blood gases were monitored. RESULTS: The mean body temperatures (+/-SEM) during the anesthetic period for the four treatments were: ISO-NORM = 37.7 +/- 0.07 degrees C, ISO-HYPO = 35.8 +/- 0.1 degrees C, HAL-NORM = 37.7 +/- 0.06 degrees C, and HAL-HYPO = 35.8 +/- 0.13 degrees C. The mean (+/-SEM) serum fentanyl concentrations (SFC) for both hypothermia treatments were significantly lower than baseline concentrations at t = 1 hour and persisted for the duration of anesthesia for the ISO-HYPO treatment but only from t = 1 to 2 hours for the HAL-HYPO treatment. Serum fentanyl concentrations returned to baseline within one hour of the end of anesthesia, regardless of body temperature. There were no significant differences between treatments for systolic or diastolic blood pressure but mean blood pressures were higher during normothermia versus hypothermia during the last hour of anesthesia. CONCLUSIONS AND CLINICAL RELEVANCE: Hypothermia during inhalation anesthesia produced a significant reduction in SFC using transdermal administration and was more protracted with isoflurane than halothane anesthesia. While significant reductions in SFC occurred, the SFC were still within the range believed to confer analgesia.

Administration, Cutaneous↗

In vivo evaluation of limonene-based transdermal therapeutic system of nicorandil in healthy human volunteers.

Hydroxypropyl methylcellulose (HPMC) gel drug reservoir system prepared with 70:30 v/v ethanol-water solvent system containing 6% w/w of limonene was effective in promoting the in vitro transdermal delivery of nicorandil. The objective of the present study was to fabricate and evaluate a limonene-based transdermal therapeutic system (TTS) for its ability to provide the desired steady-state plasma concentration of nicorandil in human volunteers. The in vitro permeation of nicorandil from a limonene-based HPMC gel drug reservoir was studied across excised rat skin (control), EVA2825 membrane, adhesive-coated EVA2825 membrane and adhesive-coated EVA2825 membrane-excised rat skin composite to account for their effect on the desired flux of nicorandil. The flux of nicorandil from the limonene-based HMPC drug reservoir across EVA2825 membrane decreased to 215.8 +/- 9.7 microg/cm(2).h when compared to that obtained from control, indicating that EVA2825 was effective as a rate-controlling membrane. The further decrease in nicorandil flux across adhesive-coated EVA2825 membrane and adhesive-coated EVA2825 membrane-excised rat skin composite showed that the adhesive coat and skin also controlled the in vitro transdermal delivery. The limonene-based drug reservoir was sandwiched between adhesive-coated EVA2825-release liner composite and a backing membrane. The resultant sandwich was heat-sealed as circle-shaped patch (20 cm(2)), trimmed and subjected to in vivo evaluation in human volunteers against immediate-release tablets of nicorandil (reference formulation). The fabricated limonene-based TTS of nicorandil provided a steady-state plasma concentration of 21.3 ng/ml up to 24 h in healthy human volunteers. It was concluded that the limonene-based TTS of nicorandil provided the desired plasma concentration of the drug for the predetermined period of time with minimal fluctuations and improved bioavailability.

Administration, Cutaneous↗

A comparison of glyceryl trinitrate with diclofenac for the treatment of primary dysmenorrhea: an open, randomized, cross-over trial.

Primary dysmenorrhea is a syndrome characterized by painful uterine contractility caused by a hypersecretion of endometrial prostaglandins; non-steroidal anti-inflammatory drugs are the first choice for its treatment. However, in vivo and in vitro studies have demonstrated that myometrial cells are also targets of the relaxant effects of nitric oxide (NO). The aim of the present study was to determine the efficacy of glyceryl trinitrate (GTN), an NO donor, in the resolution of primary dysmenorrhea in comparison with diclofenac (DCF). A total of 24 patients with the diagnosis of severe primary dysmenorrhea were studied during two consecutive menstrual cycles. In an open, cross-over, controlled design, patients were randomized to receive either DCF per os or GTN patches the first days of menses, when menstrual cramps became unendurable. In the subsequent cycle the other treatment was used. Patients received up to 3 doses/day of 50 mg DCF or 2.5 mg/24 h transdermal GTN for the first 3 days of the cycle, according to their needs. The participants recorded menstrual symptoms and possible side-effects at different times (0, 30, 60, 120 minutes) after the first dose of medication on the first day of the cycle, with both drugs. The difference in pain intensity score (DPI) was the main outcome variable. Both treatments significantly reduced DPI by the 30th minute (GTN, -12.8 +/- 17.9; DCF, -18.9 +/- 16.6). However, DCF continued to be effective in reducing pelvic pain for two hours, whereas GTN scores remained more or less stable after 30 min and significantly higher than those for DFC (after one hour: GTN, -12.8 +/- 17.9; DFC, -18.9 +/- 16.6 and after two hours: GTN, -23.7 +/- 20.5; DFC, -59.7 +/- 17.9, p = 0.0001). Low back pain was also relieved by both drugs. Headache was significantly increased by GTN but not by DCF. Eight patients stopped using GTN because headache--attributed to its use--became intolerable. These findings indicate that GTN has a reduced efficacy and tolerability by comparison with DCF in the treatment of primary dysmenorrhea.

Administration, Cutaneous↗

Postmenopausal bone loss: does HRT always work?

In a 3-year study comparing oral and transdermal HRT, we measured bone density in the spine and proximal femur by dual-photon absorptiometry. Sixty-six women were randomly allocated to receive either oral conjugated equine oestrogens, 0.625 mg daily, together with cyclical oral dl-norgestrel, 0.15 mg daily, or transdermal 17 beta-oestradiol, 0.05 mg daily, together with cyclical transdermal norethisterone acetate, 0.25 mg daily. We found that only 2% showed significant vertebral bone loss on either treatment, whilst approximately 12% lost from the proximal femur. Compliance was demonstrated by monitoring all used patches and pill packets, recording all side effects and bleeding patterns, and by the demonstration of appropriate changes in levels of gonadal steroids and lipoproteins. Comparing the bone losers with the ten highest gainers, lowers were closer to their menopause but were not different in body mass or life style. Serum oestradiol levels were similar, and both groups showed a similar response in terms of changes in bone biochemical markers and lipoproteins in response to HRT. In thus seems that a small proportion of women do not conserve bone density in the proximal femur with standard doses of HRT. It remains to be determined whether they could be identified by more specific biochemical markers of bone turnover, and whether they would maintain with a higher dose of oestrogen.

Administration, Cutaneous↗

The effect of transdermal oestradiol on bleeding pattern, hormonal profiles and sex steroid receptor distribution in the endometrium of Norplant users.

The most common side-effect and reason for discontinuation with Norplant use is bleeding disturbance. The aim of this study was to investigate whether the 6 week application of a patch which released 100 micrograms/day oestradiol would reduce the number of abnormal bleeding days or eliminate the problem. Another objective was to find out the correlation between the bleeding pattern and endometrial concentrations of oestrogen receptor (ER) and progesterone receptor (PR). Of 98 Norplant users, 34 patients had normal bleeding patterns and 64 patients had abnormal bleeding patterns. An oestradiol patch or a placebo patch were randomly used to treat 33 and 31 women with abnormal bleeding respectively. There was a clinical improvement in the oestradiol group compared with the placebo group, although this was not statistically significant. There were no correlations between PR and ER concentration and the serum oestradiol, progesterone, levonorgestrel and sex hormone-binding globulin concentrations. Significantly increased mean immunostaining scores of stromal PR were observed in those Norplant users whose endometrium had an atrophic histological appearance. The serum oestradiol concentration did not show a significant change after treatment with the oestradiol patch compared with the placebo patch.

Administration, Cutaneous↗

Effects of dosing intervals on the development of tolerance to high dose transdermal nitroglycerin.

To investigate the antiischemic efficacy and development of tolerance to transdermal nitroglycerin, 14 patients with chronic, stable angina pectoris were studied using continuous ambulatory electrocardiographic monitoring. Patients demonstrated initial hemodynamic responsiveness to sublingual nitroglycerin and were titrated to a maximally tolerated dose of 30 to 60 mg/24 hours (52 +/- 5 mg). Two crossover phases were use in a randomized, double-blind, placebo-controlled manner: continuous nitroglycerin therapy (patches containing active drug worn for 24 hours) and intermittent nitroglycerin therapy (12-hour active drug followed by a 12-hour nitrate-free period). There were no differences in frequency or duration of ischemic episodes between the placebo days of each phase. A significant effect in frequency of episodes was observed between placebo and treatment days of continuous therapy (p less than 0.05). Nonsignificant reductions in frequency and duration of ischemic episodes also occurred during intermittent therapy. The major antiischemic effect of transdermal nitroglycerin therapy occurred during the first day of treatment but was lost by 48 hours. Reductions in frequency and duration of ischemic episodes (p less than 0.05) were present on day 1 of continuous therapy but ischemic episodes returned to placebo levels by day 2, suggesting the development of tolerance. Intermittent therapy did not prevent the development of tolerance on day 2 of treatment. The results demonstrate that the use of high doses of transdermal nitroglycerin in patients with chronic, stable coronary artery disease produced a beneficial reduction in the frequency and duration of ischemia. However, the antiischemic benefit was lost between 24 nd 48 hours after the onset of continuous and intermittent therapy, presumably due to tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗