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Biomedical subjects

E S Neiss

Publications and source records attributed to E S Neiss.

At least 19 recordsLinked to original sources

Angiotensin converting enzyme inhibitors. 10. Aryl sulfonamide substituted N-[1-carboxy-3-phenylpropyl]-L-alanyl-L-proline derivatives as novel antihypertensives.

Compounds 1a-g consisting of enalaprilat covalently bonded to aryl sulfonamides, including several known thiazide diuretics, were synthesized and tested for ACE inhibitory and diuretic and overall antihypertensive effects. All compounds were potent ACE inhibitors in vitro, with IC50 = 6.5-85 nM. At 10 mg/kg iv or ip in the rat, 1a-g inhibited the AI pressor response by 76-100%; inhibition declined significantly upon oral dosing. Compounds 1a and 1f at 100 mg/kg ip in the sodium-depleted, spontaneously hypertensive rats reduced blood pressure 28-35% and 41-42%, respectively. Compounds 1a and 1f elicited natriuresis and kaliuresis without accompanying volume increases in the rat; 1c at 25 mg/kg iv induced delayed diuresis. Compound 1f has been chosen for further development.

Angiotensin-Converting Enzyme Inhibitors

Substituted arylmethyl phenyl ethers. 1. A novel series of 5-lipoxygenase inhibitors and leukotriene antagonists.

A series of new substituted arylmethyl phenyl ethers has been prepared. These compounds were tested as inhibitors of 5-lipoxygenase (5-LO) in rat neutrophils, in vitro antagonists of leukotriene-induced contraction of guinea pig (GP) lung parenchymal strips, and inhibitors of slow reacting substance of anaphylaxis (SRS-A) mediated bronchospasm in the GP in vivo. Most representatives of this new class of potential antiallergic/antiinflammatory agents showed potent inhibition of 5-LO activity in rat PMNs. The most potent compound, 2-[[3-(1-hydroxyhexyl)phenoxy]-methyl]quinoline (33), had an I50 of 0.12 microM in the rat PMN 5-LO assay and an I50 of 3.6 microM in the leukotriene-induced contraction of GP lung parenchymal strips, and it also showed 91% inhibition of SRS-A-mediated bronchospasm in the GP in vivo at 10 mg/kg, administered intraduodenally. Some of the compounds in this series were also leukotriene antagonists in vitro, and several of them showed in vivo activity against SRS-A-mediated bronchospasm in the GP.

Animals

Angiotensin-converting enzyme inhibitors: new orally active 1,4-thiazepine-2,5-diones, 1,4-thiazine-2,5-diones, and 1,4-benzothiazepine-2,5-diones possessing antihypertensive activity.

The preparation of a series of 1,4-thiazepine-2,5-diones, 1,4-thiazine-2,5-diones, and 1,4-benzothiazepine-2,5-diones and their ability in inhibiting the activity of angiotensin-converting enzyme (ACE) in vitro and in vivo were examined. These compounds are assumed to act as prodrugs since they undergo rapid ring-opening reactions to give the corresponding biologically active free SH compounds when incubated with rat plasma or when treated with aqueous 0.1 N HCl or phosphate buffer (pH 7.4). The thiazepines 23-25 and 30 are potent inhibitors of ACE when administered po to rats and are comparable in potency to captopril (1). The most active thiazines in rats, po, were 42 and 45. Of the benzothiazepines studied, 22a was the most active in inhibiting ACE in the conscious normotensive rat, ID50 = 0.15 mg/kg, po. The acute antihypertensive effects of oral administration of a number of these compounds on mean arterial pressure and heart rate were studied in spontaneously hypertensive rats (SHR) maintained on a sodium-deficient diet.

Administration, Oral

Synthesis and antiallergic activities of 1,3-oxazolo[4,5-h]quinolines.

A series of new 1,3-oxazolo[4,5-h]quinolines has been prepared. These compounds were tested as inhibitors of antigen-induced release of histamine (AIR) in vitro from rat peritoneal mast cells (RMC) and as inhibitors of IgE-mediated passive cutaneous anaphylaxis in the rat (PCA). After several modifications of the original lead, the most potent compound of the series was determined to be 5-chloro-1,3-oxazolo[4,5-h]quinoline-2-carboxylic acid methyl ester (4a). It has an IC50 of 0.3 microM in the RMC assay and an ED50 (intraperitoneal) of 0.1 mg/kg in the PCA test, which is 10 times and 60 times more potent than disodium cromoglycate (DSCG), respectively. Of greater importance, it is orally active (ED50 = 0.5 mg/kg) as an inhibitor of the PCA test.

Animals

Angiotensin-converting enzyme inhibitors. New orally active antihypertensive (mercaptoalkanoyl)- and [(acylthio)alkanoyl]glycine derivatives.

A variety of N-substituted (mercaptoalkanoyl)- and [(acylthio)alkanoyl]glycine derivatives was synthesized and their ability in inhibiting the activity of angiotensin-converting enzyme (ACE) was examined in vitro and in vivo. The acylthio derivatives prepared are assumed to act as prodrugs since they are much less active than the corresponding free SH compounds in vitro and can be expected to act in vivo only after conversion to the free sulfhydryl compounds. A number of these compounds are potent ACE inhibitors that lowered blood pressure in Na-deficient, conscious spontaneously hypertensive rats (SHR), a high renin model. One of the most active members of the series was (S)-N-cyclopentyl-N-[3-[(2,2-dimethyl-1-oxopropyl)thio]-2-methyl-1 -oxopropyl]glycine (REV 3659-(S), pivopril). Structure-activity relationships are discussed.

Administration, Oral

Angiotensin converting enzyme inhibitors. (Mercaptoaroyl)amino acids.

A series of (mercaptoaroyl)amino acids and related compounds was synthesized and tested for ability to inhibit angiotensin converting enzyme (ACE). The most active compound was N-(3-chloro-2-mercaptobenzoyl)-N-cyclopentylglycine, having an in vitro I50 = 0.28 microM. Substitution of the aromatic 3-position by small polar groups enhanced ACE inhibitory activity, whereas bulky groups diminished it. Alteration of the beta relationship between the mercaptan and amide carbonyl or masking of the thiol by acylation reduced activity. Replacement of the thiol by nitro, hydroxy, or carboxy gave compounds lacking ACE inhibitory activity.

Amino Acids

The efficacy of a potassium-sparing combination of chlorthalidone and triamterene in the control of mild and moderate hypertension. I.

Chlorthalidone 25 mg/triamterene 50 mg in once-daily oral doses was as effective in reducing blood pressure as chlorthalidone 25 mg alone. The decrease in serum potassium was statistically significantly less with the combination than for chlorthalidone. There were no notable differences between the treatments in any other measure of laboratory safety or adverse reactions.

Adult

The efficacy of a potassium-sparing combination of chlorthalidone and triamterene in the control of mild and moderate hypertension. II.

Chlorthalidone 50 mg/triamterene 50 mg in once-daily oral doses was as effective in reducing blood pressure as chlorthalidone 50 mg alone. The decrease in serum potassium was statistically significantly less with the combination than for chlorthalidone. There were no notable differences between the treatments in any other measure of laboratory safety or adverse reaction.

Adult

Chlorthalidone-triamterene: a potassium-sparing diuretic combination for the treatment of oedema.

The efficacy of a once-daily combination of chlorthalidone 50 mg plus triamterene 50 mg or chlorthalidone 100 mg plus triamterene 100 mg was compared to that of chlorthalidone 50 mg or 100 mg. This double-blind study was carried out in eighty-eight patients over a treatment period of 12 weeks. All patients entered the active medication period of 12 weeks after a placebo run-in period of 3 to 7 days, during which pretibial or malleolar pitting oedema averaging 2 to 4 mm developed. All patients started at the lower doses, i.e. forty-one started on chlorthalidone 50 mg plus triamterene 50 mg and forty-seven started on chlorthalidone 50 mg. The protocol provided for doubling the dose (but not for reducing it thereafter) at any time during the 12-week period when control of oedema was deemed inadequate. Eight of the combination therapy patients and sixteen of those on chlorthalidone required the higher doses. By Week 12, 96% of the chlorthalidone plus triamterene patients and 100% of the chlorthalidone patients had shown a reduction of at least 2 mm in depth of pits, and 92% and 72%, respectively, had complete disappearance of oedema. The decreases in pitting oedema were paralleled by mean weight losses of 2.4 kg and 3.1 kg, respectively, for the combination treatment group and the chlorthalidone group. Average serum potassium levels throughout the 12-week treatment period were 3.70 mEq/L for the patients taking the combination compared to 3.41 mEq/L of those taking chlorthalidone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Long-term experience with indapamide.

Indapamide, 2.5 mg administered once daily for periods up to 36 months, was found to be safe and effective for the long-term control of mild to moderate hypertension. The effects of hydrochlorothiazide, 50 mg, and indapamide, 2.5 mg, were studied in two randomized, double-blind, multicenter trials. Data from the two multicenter trials (20 study sites) were pooled for purposes of comparison. Significant reductions in systolic and diastolic blood pressure, with patients in both supine and standing positions, occurred in both groups within the first 8 weeks of treatment. This effect was maintained throughout the active treatment period. Success, as determined by the therapeutic success rate (percentage of patients with decreases of standing phase V diastolic blood pressure of at least 10 mm Hg or to below 90 mm Hg), occurred in 53% of the patients given hydrochlorothiazide and in 56% of the indapamide-treated patients. During the study period, the nature, frequency, and severity of adverse reactions were similar for both groups. There was no clinically significant difference between the treatment groups for the laboratory assessments. Patients who completed the multicenter trials were eligible for participation in an ongoing long-term extension study of the safety of indapamide. Data are available for periods up to 36 months and demonstrate neither augmentation of clinical or laboratory adverse effects nor any potentially harmful indicators that could be attributed to prolonged treatment.

Adult

Indapamide in the stepped-care treatment of obese hypertensive patients.

A double-blind study was carried out in obese patients with moderately severe hypertension to assess the efficacy and tolerability of 2.5 mg indapamide as a once-a-day Step 1 drug compared to 50 mg hydrochlorothiazide also as a once-a-day Step 1 drug; to assess the efficacy and tolerability of a fixed daily dose of 2.5 mg indapamide administered concomitantly with methyldopa starting at 500 mg daily; and to compare the findings of efficacy and tolerability of 2.5 mg indapamide daily with those of 50 mg hydrochlorothiazide daily as Step 1 agents when methyldopa is the Step 2 drug. Twenty-nine patients completed the study and were evaluated. Nine patients achieved the study criterion of reduction of average standing diastolic pressure to 90 mmHg or less when treated with Step 1 medication only. Twenty patients required the addition of methyldopa to their Step 1 medication: 10 patients took 2.5 mg indapamide with an average constant daily dose of 1100 mg methyldopa and 10 patients took 50 mg hydrochlorothiazide with an average constant daily dose of 1575 mg methyldopa to achieve blood pressure control. All groups had mean diastolic pressure controlled at or below the 90 mmHg criterion during the period of constant methyldopa dosage for those patients who required Step 2 therapy. There were no significant differences between groups with respect to diastolic pressure during the constant dosage period. The indapamide patients required significantly (p less than 0.05) less methyldopa than did the hydrochlorothiazide patients in order to maintain satisfactory control of diastolic blood pressure. The number of responders was greater in the 2.5 mg indapamide + methyldopa group than it was in the 50 mg hydrochlorothiazide + methyldopa group, and responses were achieved more rapidly in the former group than in the latter. Indapamide (2.5 mg per day) was effective and well tolerated when used alone or as Step 1 medication in combination with methyldopa as Step 2 medication, and it compared favourably in this regard with hydrochlorothiazide.

Adult

Multi-centre clinical investigation of indapamide in the United States: a review.

Indapamide, a new indoline antihypertensive agent, has been the subject of a worldwide programme to develop this drug for general clinical use. The results are described of the multi-centre U.S. clinical programme demonstrating the effectiveness and tolerance of indapamide for the treatment of hypertension. All work was conducted under U.S. Federal Food and Drug Administration guidelines, and resulted recently in a New Drug Application. A total of 1891 subjects or patients participated in 27 separate studies conducted by 91 investigators. In controlled clinical trials comparing 2.5 mg indapamide once daily with 50 mg hydrochlorothiazide once daily for 40 weeks in patients with mild to moderate essential hypertension, indapamide produced a reduction of supine blood pressure of -9.5/-14.3 mmHg as compared with -7.6/-11.4 mmHg for hydrochlorothiazide. In combination with methyldopa, propranolol, clonidine, guanethidine and hydralazine, indapamide consistently produced a greater decrease in arterial pressure than did those agents given alone. Indapamide added to these step-care agents did not result in a meaningful increase in adverse reactions. Indapamide has been the subject of a long-term safety study in which over 100 hypertensive patients have been followed up for 2 years or longer. During this period of time, indapamide was well tolerated and remained effective. No biochemical, electrocardiographic or ophthalmological changes were associated with its use. Other studies with indapamide are discussed describing the systemic and renal haemodynamic effects, pharmacokinetic properties and special safety studies conducted with this agent. The use of indapamide in patients with hepatic or renal impairment is reviewed in detail.

Antihypertensive Agents

Multicenter dose-response study of the effect of indapamide in the treatment of patients with mild to moderate hypertension.

This study, carried out in three centers in the United States, investigated the antihypertensive effect of three dosages of indapamide in 87 patients with mild to moderate hypertension. The dosages studied were 1 mg, 2.5 mg, and 5 mg daily. A double-blind, parallel study design was used with a six-week placebo run-in period followed by an eight-week treatment period and a two-week follow-up period. Compared with placebo, all dosages caused a significant decrease (P less than 0.05) in blood pressure, with an average decrease of approximately 6 mmHg diastolic and 13 mmHg systolic. The antihypertensive effect seemed to be fully manifest after six weeks of treatment. At all dosage levels, indapamide produced markedly greater therapeutic success rates than did the placebo. Success was defined as either a standing phase-5 diastolic blood pressure of less than 90 mmHg or a decrease by at least 10 mmHg from baseline. Although the decrease in mean serum potassium concentration was dose-related, the decrease was not clinically significant with any dose. A reduction in serum chloride and increases in serum uric acid and glucose were also observed. These changes were slight and did not cause the discontinuation of treatment for any patient. The most frequently observed side effects were mild to moderately severe dizziness, weakness, and headaches.

Adult

Inhibition of compound 48/80 induced mediator release following oral administration of tiaramide hydrochloride in normal subjects.

The ability of tiaramide hydrochloride (RHC 2592) to inhibit cutaneous reactivity was studied using 11 normal volunteers. After repeated administration tiaramide hydrochloride inhibited cutaneous mast cell mediator release induced by compound 48/80 while not affecting histamine-induced cutaneous reactivity. This is the first demonstration in man of an oral agent with such an effect.

Administration, Oral

Preliminary report on the effects of tiaramide on the ice cube test in patients with idiopathic cold urticaria.

Three subjects diagnosed as having idiopathic acquired cold urticaria were studied to assess the ability of orally administered tiaramide to inhibit the wheal induced following cold challenge with ice cubes placed in contact with the skin, and to establish the safety of multiple doses of 250 mg, q.i.d., for one week administered after a single oral dose of 500 mg. Two subjects completed the study. One subject was known to be unresponsive to antihistamines for allergy and the second was intolerant of antihistamines due to side effects. A third subject discontinued treatment due to an adverse reaction experienced while on the study medication. The skin of the forearm of each subject was exposed to cold stimuli for 1, 2, 3, 4, and 5 minutes by placing five ice cubes on the ventral surface at one minute intervals, and removing all simultaneously five minutes after contact with the first cube. The challenge sites were observed for ten minutes and the area of the wheal, intensity of edema and the time of contact necessary to induce the skin response were recorded. The results of this provocative test following the single and multiple dosage administration of tiaramide were compared to baseline skin responses. After one week of tiaramide treatment at 250 mg, q.i.d., both subjects who completed the study had a markedly attenuated skin response to cold challenge and no adverse effects. Our results suggest that absorbable compounds that can inhibit mast cell degranulation may be efficacious in cold urticaria and of particular value in treating patients who do not respond to standard therapy.

Adult

Pharmacokinetics and bioavailability of indapamide--a new antihypertensive drug.

Two formulations of indapamide tablets (2.5 mg) were given as a 5.0 mg dose and the subsequent blood levels were compared to those obtained after administration of a 5.0 mg solution. The study was conducted as a randomized three-way crossover design using healthy male volunteers. The drug was well tolerated by all the subjects involved. The area under the blood concentration versus time curve, extrapolated to infinity was essentially the same for all three formulations (4.2, 4.7, and 4.4 microgram-h/ml). Statistical comparison of the blood levels from the two tablets showed that one tablet had a significantly shorter time of maximum blood concentration (2.3 vs 3.5). Cmax(333ng/ml) and tmax (0.7h) values for the solution were significantly higher than either tablet. The average half-life (beta-phase) for all three formulations was 15 h, while the average systemic clearance was 20 ml/min. Indapamide has a low clearance rate and there was no evidence that the drug undergoes a first-pass effect.

Adolescent