The effect of tenidap on the anti-hypertensive efficacy of thiazide diuretics in patients treated for mild to moderate hypertension

1. This randomised, placebo-controlled, double-blind, parallel-group study was conducted to assess the effect of tenidap sodium 120 mg, a novel anti-arthritic cytokine modulating drug, on the hypotensive efficacy of the thiazide diuretics hydrochlorothiazide or bendrofluazide. 2. Twenty-three male and female patients, aged 41-78 years, with mild to moderate, uncomplicated, essential hypertension controlled with thiazide diuretic therapy, received either a single daily dose of tenidap sodium 120 mg or matched placebo for 22 days in addition to their diuretic therapy. Changes between baseline and endpoint in supine and standing systolic and diastolic pressures and pulse rate were compared between treatment groups. 3. Daily treatment with tenidap reduced the anti-hypertensive efficacy of the thiazide diuretics. Blood pressure tended to increase marginally and the increase in mean standing diastolic pressure observed with tenidap was significantly greater than the change in the placebo group. All pressures tended to decrease in the placebo group and all endpoint measurements were within 7 mm Hg of baseline in both groups. 4. Treatment-related side effects of mild to moderate severity were reported in two subjects receiving tenidap, but in neither case was treatment discontinued. Two subjects receiving placebo also experienced side effects considered to be treatment-related and both were withdrawn from the study. 5. The results of this study suggest that tenidap may be given to patients treated for mild to moderate essential hypertension controlled with thiazide therapy; however, the patient's blood pressure should be regularly monitored.

Adrenocortical steroids increase renal thiazide diuretic receptor density and response

The density of the rat renal pharmacologic receptor for thiazide-type diuretics, as quantitated by the maximal specific binding of (3H)metolazone, decreased to one-third normal after adrenalectomy. Selective glucocorticoid (dexamethasone or RU-28362) replacement increased thiazide receptor density to or above the normal level over the dose range of steroid that decreased thymus weight, which served as a bioassay for glucocorticoid activity. Mineralocorticoid (fludrocortisone or aldosterone), in doses that did not decrease thymus weight, also increased thiazide diuretic receptor density to or above normal. The addition of glucocorticoid (RU-28362) to maximal aldosterone increased thiazide receptor above that produced by aldosterone alone and to threefold normal. Similarly, the addition of aldosterone to high-dose RU-28362 also increased thiazide receptor density above that produced by the glucocorticoid alone and to threefold normal. Hence, the effects of glucocorticoids and mineralocorticoids appeared to be additive. The increase in renal thiazide receptor density produced by fludrocortisone, at a dose that elicited both mineralocorticoid and glucocorticoid effects, was unrelated to the basal (prethiazide) renal excretion of sodium, potassium, chloride, or calcium. However, fludrocortisone-pretreated animals responded to bendroflumethiazide with a greater natriuresis than did controls. In addition, the magnitudes of the thiazide-elicited natriuresis and chloriuresis correlated significantly with thiazide receptor. It was concluded that both the density of the renal thiazide receptor and the quantity of sodium and chloride reabsorbed by the thiazide-sensitive Na-Cl cotransporter in the kidney are under adrenocortical regulation.

Cell Cl and transepithelial na transport in toad urinary bladder

Relationships between short-circuit current (Isc), cell Cl and the mechanism(s) of Cl accumulation in toad bladder epithelial cells were investigated. In serosal Cl-free gluconate Ringer, 80% of the cell Cl (measured by x-ray microanalysis) was lost over 30-60 min with an associated decrease in cell water content. concomitantly, Isc fell to 20% of its initial value within 10 min but then recovered to 45% of its initial value despite continued Cl loss. With the reintroduction of Cl, cell Cl and Isc both recovered within 10 min. Serosal SITS (4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonate; 0.5 mM) plus bumetanide (0.1 mM), did not prevent the fall in Isc or the loss of cell Cl in gluconate medium, although they did inhibit subsequent recovery of Isc in this medium. They also prevented the recovery of Isc in Cl medium but not the reaccumulation of Cl by the cells. Although SITS and bumetanide did not prevent the loss or recovery of Cl, they modified the pattern of the ion changes. In their absence, changes in cellular Cl were twice that of the changes in measured cellular cations implicating basolateral Cl/HCO3 exchange in Cl movement. With SITS plus bumetanide present, changes of similar magnitude in Cl were associated with equivalent changes in cation, consistent with the inhibition of Cl/HCO3 exchange.

Influence of gender on renal thiazide diuretic receptor density and response

The influence of gender and gonadectomy on (1) the density of the renal thiazide-sensitive ion transporter, as quantitated by the ability of renal membranes to bind (3H)metolazone, and (2) the changes in the urinary excretion of electrolytes caused by maximal bendroflumethiazide (BFTZ) in Sprague-Dawley rats was determined. The density of the thiazide receptor was twofold higher (P < 0.001) in females than in males. Orchiectomy increased thiazide receptor significantly in one of two studies (P < 0.01). Ovariectomy decreased thiazide receptor by more than 20% (P < 0.01) in both studies. The rates of the urinary excretion of sodium and chloride after BFTZ and the increases in the urinary excretion of sodium, chloride, and ammonium caused by BFTZ were greater in intact females than in intact males; BFTZ decreased the urinary excretion of calcium 50% in intact females, but not in intact males. Regression analysis of the thiazide receptor (in intact and gonadectomized animals) versus the urinary excretion of electrolytes before and after BFTZ yielded a model in which one-third of the variation in thiazide receptor could be related to the change in the excretion of calcium and ammonium produced by BFTZ, raising the possibility that the density of the thiazide receptor might be related to calcium or acid-base homeostasis. It was concluded that the renal excretion of sodium, chloride, calcium, and ammonium are, in part, controlled by gender and sex hormones via their regulation of the renal density of the thiazide diuretic receptor.

Blockade of distal nephron sodium transport attenuates pressure natriuresis in dogs

The sodium excretory responses (UNaV) to acute changes in renal arterial pressure (RAP) during blockade of distal nephron sodium transport were evaluated in seven sodium-replete anesthetized dogs. The major distal sodium entry pathways were blocked by intrarenal infusion of amiloride (AM, 10(-5) mol/L) and bendroflumethiazide (BZ, 10(-6) mol/L). Infusion of AM plus BZ caused slight increases in renal blood flow (RBF, 4.1 +/- 0.5 to 4.6 +/- 0.4 mL.min-1.g-1; P < .001) but no changes in glomerular filtration rate (GFR, 0.96 +/- 0.05 to 1.01 +/- 0.07 mL.min-1.g-1; P = NS) or autoregulatory efficiency of RBF and GFR. There were significant increases in UNaV (2.7 +/- 0.7 to 5.2 +/- 0.6 mumol.min-1.g-1) and fractional excretion of sodium (FENa, 1.8 +/- 0.4% to 3.5 +/- 0.3%) and decreases in potassium excretion (0.59 +/- 0.10 to 0.35 +/- 0.06 mumol.min-1.g-1) during AM plus BZ infusion. During the control period and during repeat measurements in time control studies, decreases in RAP (150 to 100 mm Hg) elicited the usual decreases in UNaV (slope, 0.022 +/- 0.007 mumol.min-1.g-1.mm Hg-1; P < .01). After administration of AM plus BZ, there was a marked attenuation of the pressure-natriuretic responses, and the slopes of the RAP versus UNaV and RAP versus FENa relations at RAP levels above 100 mm Hg were not significantly different from zero. However, the pressure-natriuresis response was maintained at arterial pressure between 75 and 100 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal adaptations to continuous administration of furosemide and bendroflumethiazide in rats

During continuous treatment with diuretics, the kidney adapts to the initial Na loss by activating antinatriuretic mechanisms which serve to prevent further Na and volume losses. To study the renal sites of adaptations to constant diuretic treatment, bendroflumethiazide (4 mg daily), furosemide (8 mg daily) or vehicle (0.24 ml daily) was infused intraperitoneally to female Wistar rats by implanted osmotic minipumps. Half of the animals (groups vol.) were randomized to receive a balanced saline solution to drink in addition to water in order to replace Na, K and volume losses. On the 6th day of treatment, clearances of inulin, Na, and Li were determined during four consecutive 6 hr periods. Circadian changes in renal excretions occurred in all groups with highest excretions of Na, Li and water in the dark period (6 p.m. to 6 a.m.). Renal changes induced by continuous infusion of diuretics were most pronounced in the dark period and would probably not have been disclosed if the clearance experiments had been restricted to the daytime. The average 24-hour clearance for inulin (glomerular filtration rate) was not different among groups, except for a 20% decrease in the furosemide group. The 24-hour fractional Na excretion, being approximately 0.5% in the vehicle group, increased to approximately 0.8% in group (bendroflumethiazide+vol) and to approximately 2.8% in group (furosemide+vol) but was not different from the vehicle group in the diuretic groups without volume replacement.(ABSTRACT TRUNCATED AT 250 WORDS)

Do thiazides reduce intestinal oxalate absorption?: a study in vitro using rabbit colon

1. The purpose of the present study was to examine the effects of various diuretics on intestinal oxalate transport. Transmural oxalate fluxes were measured across isolated, short-circuited tissue segments removed from rabbits and placed in Ussing chambers. 2. The net absorptive flux of oxalate across the distal colon was significantly reduced in the presence of trichlormethiazide at 10(-4) mol/l. In contrast, this diuretic had no effect on oxalate transport in the other intestinal segments examined. Several of the thiazide diuretics tested had some inhibitory effect on colonic oxalate absorption, but at higher concentrations of 10(-3) mol/l or 10(-2) mol/l. 3. We conclude that the previously reported hypooxaluric effects of hydrochlorothiazide and chlorthalidone are most likely not the result of an exclusive or primary effect on intestinal oxalate transport. It is suggested that the reduction in colonic oxalate absorption that was observed with the thiazides probably involves the transport system responsible for oxalate efflux across the basolateral membrane of the colonocyte.

Central effects of combined bendrofluazide and atenolol administration. A single dose study in normal subjects

Twelve normal male subjects received single oral doses of atenolol 100 mg (AT), bendrofluazide 5 mg (BFZ), combined atenolol 100 mg and bendrofluazide 5 mg (AT/BFZ), diazepam 5 mg (Dz), or one of two matching placebos, on each of 6 study days. Tests of psychomotor performance [digit symbol substitution (DSST), letter cancellation (LCT), continuous attention, choice reaction time (CRT), finger tapping, short-term memory, body sway], physiological measurements [critical flicker fusion (CFF), two-flash fusion (2FF)] and subjective assessments using visual analogue scales (VAS), were performed at 2 and 4 hours post-ingestion. Dz (active control) significantly worsened VAS scores at 2 h (+0.68) and reduced DSST scores at both 2 h (-15.0) and 4 h (-11.0). AT and BFZ given alone, each produced significant worsening of VAS at 2 h [AT +1.0; BFZ +1.38], but had no significant effects on performance. In combination however, AT/BFZ at 4 h produced significant impairment of DSST scores (-10.4), reduced finger tapping (-16.5) and increased involuntary rest pauses (+16.5). Despite these effects, no change in VAS scores occurred. In summary, we have demonstrated significant impairment of psychomotor performance in normal subjects with the AT/BFZ combination, which was not evident with the single agents and which occurred in the absence of a change in subjective awareness. These central effects may have important clinical implications for patients taking combined antihypertensive medication.

Oral mucosal friction and subjective perception of dry mouth in relation to salivary secretion

Assessment of oral mucosal friction and subjective perception of dry mouth was performed during treatment with thiazide diuretic bendroflumethiazide (2.5 mg o.d.) or placebo in a randomized, double-blind, cross-over study (2 x 2 wk) in 34 healthy volunteers. Treatment with bendroflumethiazide was associated with a 10% reduction in the stimulated whole saliva secretion rate and a 15% reduction in the salivary sodium concentration, as compared with placebo. Oral mucosal friction was concomitantly measured on the buccal mucosa and on the mucosa of the lower lip by means of a newly developed sliding friction device. In addition, a questionnaire was used to evaluate how the treatment was subjectively perceived with regard to symptoms of dry mouth. Mucosal friction of the lower lip increased significantly during treatment with bendroflumethiazide, as compared with placebo. When the test subjects, regardless of pharmacologic treatment, were divided into groups according to subjective perception of dry mouth, the dry mouth group showed significantly lower resting and stimulated flow rate and higher mucosal friction in comparison to the nondry group. When, in addition, pharmacologic treatment was also considered, the differences between the dry and the nondry group were restricted to resting whole saliva flow rate and mucosal friction during bendroflumethiazide treatment. It is concluded that resting whole saliva flow rate is the best predictive factor for evaluating subjectively perceived dry mouth. However, the sensitivity of the developed sliding friction device is capable of detecting minor changes in salivary secretion rate. In addition, measurements of oral mucosal friction may serve as an easily available method to complement sialometry when evaluating, for example, drug-induced dryness of the mouth.

Electrocardiographic changes induced by inhaled salbutamol after treatment with bendrofluazide: effects of replacement therapy with potassium, magnesium and triamterene

1. Twelve normal subjects were given 5 days' treatment with (a) placebo; (b) 5 mg of bendrofluazide; (c) 5 mg of bendrofluazide plus 24 mmol of potassium; (d) 5 mg of bendrofluazide plus 24 mmol of magnesium; (e) 5 mg of bendrofluazide plus 24 mmol of potassium plus 24 mmol of magnesium; (f) 5 mg of bendrofluazide plus 50 mg of triamterene. 2. After each treatment period, subjects were given two doses of inhaled salbutamol (each of 1 mg), and measurements were made 25 min after each dose. 3. Treatment with bendrofluazide plus salbutamol produced a lower absolute level of plasma potassium than salbutamol alone, although the addition of potassium, magnesium or triamterene did not attenuate this effect. Plasma magnesium was unchanged by salbutamol. 4. Salbutamol was associated with significant electrocardiographic effects, including T-wave flattening, Q-Tc interval prolongation and, in some subjects, U-waves and S-T segment depression. 5. Prior treatment with bendrofluazide potentiated the electrocardiographic effects of salbutamol. Supplementation with potassium and magnesium had no effect on electrocardiographic changes, and the addition of triamterene to bendrofluazide only attenuated electrocardiographic responses in some subjects.

Effects of the thiazide diuretic bendroflumethiazide on salivary flow rate and composition

Thiazide diuretics are among the first-line alternatives in the treatment of primary hypertension. The effects of thiazide treatment on salivary production are, however, little studied and the results so far available are not decisive. The aim of the present study was to evaluate and compare salivary flow rate and composition during treatment with the thiazide diuretic bendroflumethiazide in a low dose (2.5 mg o.d.) and placebo. The study was performed with a randomized, double-blind, cross-over design (2 x 2 wk) in 34 healthy volunteers. The treatment periods were separated by a wash-out period of 2 wk. Resting and stimulated whole saliva was sampled three times daily on scheduled days during the treatment periods. Flow rate was assessed for resting saliva, whereas flow rate, pH, buffer capacity, amount of total proteins and concentrations of sodium, potassium, calcium, phosphate and magnesium were measured for stimulated whole saliva. No effect of bendroflumethiazide on the resting salivary flow rate could be detected, while the stimulated flow rate was significantly reduced by about 10% during the thiazide treatment. The total sodium output was significantly decreased by approximately 30%, without any detectable change in total potassium output. All other variables of stimulated whole saliva studied were not different from placebo. It is concluded that treatment with bendroflumethiazide in a low dose significantly reduces the stimulated whole salivary flow rate and total sodium output in healthy volunteers.

Acute effects of thiazides, with and without carbonic anhydrase inhibiting activity, on lithium and free water clearance in man

1. The acute effects of chlorothiazide and bendroflumethiazide on renal Li+ clearance (CLi) were studied in Na+-restricted healthy humans during maximum water diuresis. 2. Chlorothiazide, which has marked carbonic anhydrase inhibiting activity, increased CLi by about 25%. The concomitant rise in uric acid clearance, maximum urine flow and bicarbonate excretion suggests that this drug suppressed proximal reabsorption through carbonic anhydrase inhibition, which would also explain the observed fall in glomerular filtration rate (increased glomerulotubular feedback activity). 3. Bendroflumethiazide, which lacks carbonic anhydrase inhibiting activity, did not affect CLi or any of the other above-mentioned variables. 4. It is concluded from the lack of an effect of bendroflumethiazide on CLi that Li+ is not reabsorbed in thiazide-sensitive segments of the human distal nephron. The rise in CLi after chlorothiazide is most likely due to suppressed Li+ reabsorption in the proximal tubules resulting from carbonic anhydrase inhibition. 5. The results of this study are compatible with the concept that CLi is an index of Na+ and water delivery from the proximal tubules in humans.

Amphibian cornea as a model for studying intrinsic activities of loop diuretics

The inhibitory activity of various standard diuretics and compounds on Cl- transport in the toad cornea has been investigated. The relative potency of these diuretics shows a pattern and follows a sequence similar to their inhibitory potency on salt reabsorption in the isolated mammalian cortical thick ascending limb of Henle's loop. The suitability and convenience of using toad cornea as an in vitro model for that segment of the mammalian nephron is well demonstrated.

The effect of diuretics and lithium on 3H-ouabain binding site concentration and Na,K-content in rat skeletal muscle

Previous studies have shown an increase in 3H-ouabain binding sites or Na, K-pumps in vitro in cultured cells in response to incubation in low K, diuretics or lithium. However, in the present study the administration in vivo of various diuretics or lithium combined with supplementary K was not associated with any significant changes in Na,K-content or 3H-ouabain binding site concentration in rat skeletal muscle. When the diuretics were administered in combination with only the basal K requirement a decrease in both K-content and 3H-ouabain binding site concentration was seen. This indicates that the decrease in 3H-ouabain binding site concentration is not caused by these drugs per se but is secondary to the associated K-depletion. The discrepancy between the results obtained using isolated cells and rat skeletal muscles could be related to the fact that cultured cells are not subject to the normal growth control of the intact organism. It should be emphasized that results obtained using cultured cells do not necessarily reflect processes taking place in the intact organism.

Interaction by bendrofluazide with acetylsalicylic acid

The effects of aspirin and bendrofluazide alone and in combination were studied on the diuresis, natriuresis, kalliuresis and excretion of salicylates in normal human volunteers. The simultaneous administration of both drugs in a sequence of aspirin-bendrofluazide was accompanied by a reduction in the kalliuretic effect of aspirin without any significant effects on the natriuresis, kalliuresis and diuresis induced by bendrofluazide. Concomitant administration of both drugs produced marked increases in the amount of salicylate excreted over the experimental session, being highest (58.3%) with an aspirin-bendrofluazide sequence, and lowest (30.3%) when injected simultaneously (suggesting antagonism by bendrofluazide). The results suggest interference by bendrofluazide with the excretion of salicylate but not vice versa.

Diurnal variation of urine composition in calcium oxalate stone disease during treatment with bendroflumethiazide

Urine samples, collected hourly between 6.00 and 23.00 h and in one single night fraction, were analyzed for calcium (Ca) and magnesium (Mg) before and during daily administration of 5 mg bendroflumethiazide to 13 Ca-oxalate (CaOx) stone formers. In some of them urinary oxalate (Ox), citrate and sodium were analyzed as well. Bendroflumethiazide was administered in divided doses to 7 and in a single dose to 6 patients. After 4-8 weeks of treatment urinary Ca decreased by approximately 25% in both groups and the reduction was evenly distributed over the day. The reduction of the Ca/Mg quotient and the CaOx risk index was most pronounced following meals. The AP(CaOx) index, an estimate of the CaOx ion activity product, was favorably reduced. No important differences were recorded for the different types of bendroflumethiazide administration and thus one single dose might be equally as efficient as two divided doses.

The effect of bendroflumethiazide and hydrochlorothiazide on the rate of dissolution of calcium hydroxyapatite

Inhibition of dissolution of calcium hydroxyapatite in the presence of bendroflumethiazide, Centyl, and of hydrochlorothiazide has been investigated. The former compound has a pronounced larger inhibitory effect than the latter. The trifluormethyl group in bendroflumethiazide has been shown to hydrolyze, with the release of fluoride and hydrogen ions, presumably forming a carboxylic acid. The inhibitory effect of hydrolyzed bendroflumethiazide is found to be similar to the effect of a potassium fluoride solution with the same fluoride ion concentration, as measured by a fluoride selective ion electrode.

Comparison of the hypotensive and metabolic effects of bendrofluazide therapy and a high fibre, low fat, low sodium diet in diabetic subjects with mild hypertension

Fifty diabetic patients with mild hypertension were treated by a high fibre, low fat and low sodium diet or bendrofluazide for a three-month period. These two well-matched groups had a similar highly significant decrease in both systolic (P less than 0.001) and diastolic blood pressure (P less than 0.001). Both groups lost weight, the weight loss being greater in those receiving dietary therapy. Only dietary therapy was associated with a significant elevation of HDL2 level (P less than 0.05) and decrease in glycosylated haemoglobin (P less than 0.01). Bendrofluazide therapy resulted in significant elevation of glycosylated haemoglobin level (P less than 0.05) and at the end of the study this group had significantly higher glycosylated haemoglobin level (P less than 0.05) than the diet treated group. In those patients who were also hyperlipidaemic, dietary therapy resulted in a significant decrease of mean serum cholesterol (P less than 0.02), triglyceride (P less than 0.01) and glycosylated haemoglobin (P less than 0.01) while bendrofluazide treatment tended to elevate these levels. We conclude that a high fibre, low fat and low sodium dietary regimen lowers blood pressure, improves several other coronary risk factors and appears free of side-effects. This modified diet may be an attractive alternative to thiazide diuretic therapy in the mildly hypertensive diabetic subject.

Comparison of the hypotensive effects of bendrofluazide, bumetanide and xipamide

A randomized, triple crossover study was carried out in 24 elderly patients requiring chronic diuretic therapy to assess the different hypotensive effects of a fixed daily dose of 5 mg bendrofluazide, 1 mg bumetanide and 40 mg xipamide. Each treatment was given for 3 months. The results showed that no significant weight change took place during the study period. There was, however, a significant (p less than 0.001) decrease compared to baseline values both in systolic and diastolic blood pressure during the xipamide period and a decrease in diastolic blood pressure (p less than 0.05) when taking bumetanide. Only minor side-effects were reported.

Effect of bendrofluazide on the renin-angiotensin-aldosterone system and prostaglandins in captopril-resistant hypertensive patients

In a double-blind cross-over trial 15 captopril (daily dose 600 mg) treated patients, received in addition to the converting-enzyme inhibitor, placebo or bendrofluazide (7.5 mg). Bendrofluazide lowered blood pressure, while body weight decreased slightly. During captopril-bendrofluazide treatment, the plasma renin-angiotensin-aldosterone system was stimulated, while no effect on the urinary excretion of prostaglandin E2 and F2 alpha was found.

Effect of thiazides on the urinary calcium oxalate stone-forming potential in normal males

We studied the effect of bendroflumethiazide on a risk factor index, COSP, reflecting the stone-forming potential of urinary calcium oxalate. This index includes the concentrations of three stone promotors: calcium, oxalate, and uric acid in its numerator, and two stone inhibitors: magnesium and citrate, in its denominator. These risk factors were measured in 4-hour and 24-hour urinary specimens obtained under fixed conditions of food and fluid intake. Eight normal males were studied before and after two and four weeks of continued thiazide treatment. Thiazide 2.5 mg b.i.d. was given for two weeks, followed by 2.5 mg t.i.d. for another two weeks. Before treatment COSP exhibited a pronounced diurnal variation with peaks between 8 a.m. and noon, and 8 p.m. and midnight. After four weeks of thiazide treatment suppression of two stone promotors, calcium (p less than 0.01) and uric acid (p less than 0.02), and reduced COSP by 36 to 95% in each subject (median: -71%, p less than 0.01). Moreover, thiazide abolished the diurnal variation of COSP. After the initial two weeks of thiazide 2.5 mg b.i.d., almost identical effects were observed. Nearly all the changes in COSP were explained by the effects on urinary calcium. This marked suppression of COSP supports the theory that thiazides may be useful in the prevention of renal calcium oxalate stone formation.

Comparative pharmacological and pharmacokinetic observations on propranolol (long acting formulation) and bendrofluazide administered separately and concurrently to volunteers

1 The effect of long-acting (LA) propranolol, LA propranolol and bendrofluazide, and a new combined formulation of LA propranolol/bendrofluazide (Inderex) on exercise tachycardia was studied in ten normal volunteers. 2 The preparations were given in random order, double-blind, on three separate study weeks. Observations were made 0, 1, 3, 6, 8, 24, 33 and 48 h after drug administration. 3 The three preparations produced a significant reduction in exercise tachycardia up to 48 h after drug administration, and the effects of the three preparations were not significantly different from each other. 4 Following LA propranolol, LA propranolol and bendrofluazide, and the combined formulation the mean reductions in exercise heart rate 24 h after drug administration were 16.7 +/- 2.1%, 13.0 +/- 1.8% and 16.2 +/- 1.7% respectively. 5 Plasma levels of propranolol and bendrofluazide were measured at 0, 1, 2, 3, 6, 8, 10, 12, 24, 33 and 48 h after dose administration. 6 There was no significant difference in plasma propranolol levels, Cmax propranolol or AUCo-x following the three preparations. The mean apparent t1/2 beta of propranolol after LA propranolol alone was significantly shorter than following the other two preparations (P less than 0.05), but this was not associated with a different pharmacodynamic response. 7 There was no significant difference in the pharmacokinetic parameters of bendrofluazide following the two preparations containing bendrofluazide. No bendrofluazide was detected in plasma after LA propranolol alone. 8 The new combined formulation produces similar pharmacodynamic and pharmacokinetic responses to LA propranolol and bendrofluazide given separately, and to LA propranolol given alone, and so may be of value in the treatment of hypertension.

Reduction of the effects of diuretics or sodium chloride loading in the conscious rat by inhibitors of prostaglandin synthesis

In conscious rats pretreatment with indomethacin or flurbiprofen, two chemically unrelated inhibitors of prostaglandin synthesis, reduced urine volume and sodium excretion induced by four diuretics, acetazolamide, amiloride, bendrofluazide and frusemide, or oral sodium chloride loads. The maximum reduction in sodium excretion was limited to approximately 2 mmol/kg Na+ even when sodium excretion was greatly increased. In contrast these inhibitors did not appreciably affect potassium excretion. These results indicate that part of the natriuretic response in the rat to highly and moderately efficacious diuretics and to sodium chloride loading is modified by prostaglandins. We suggest that the lack of effects on potassium excretion indicate that the collecting tubule is the probable site of action.

Effects of two years' estrogen-gestagen replacement on climacteric symptoms and gonadotropins in the early postmenopausal period

The effects of estrogen/gestagen (e/g) treatment given in a 28-day cycle (Trisequens forteR, Novo) on menopausal symptoms and plasma concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were studied in a placebo trial. 119 normal women in the early postmenopausal period with mild to moderate climacteric complaints were included. At 3-month intervals for 2 years the participants were examined and filled in questionnaires containing the 11 symptoms of the Kupperman index (10). For each symptom a score was given. In the e/g group 77% (43/56) completed the trial compared with 83% (54/63) in the control group. A total of 61% of the women complained of hot flushes and from 9% to 44% complained of the remaining 10 Kupperman symptoms. At all eight examinations e/g treatment was found to have reduced the symptom score as well as the proportion of women with hot flushes, paresthesia, insomnia, nervousness, vertigo and formication. The symptom score of hot flushes and insomnia declined significantly (p less than 0.01). In the 24 women with hot flushes and in the 19 without, e/g caused similar reduction in the mean score of the other 10 symptoms. No placebo effect was seen. E/g caused a significant (p less than 0.01) fall in the elevated plasma concentrations of FSH and LH. Vaginal bleeding was regular in 38/43 and irregular in 4/43 women during hormone treatment. No serious side effects were attributed to e/g therapy. It is concluded that e/g treatment, in addition to its beneficial effects on hot flushes and insomnia, also alleviates several other climacteric symptoms.