Biomedical subjects

R L Reeves

Publications and source records attributed to R L Reeves.

15 recordsLinked to original sources

PubMed1992

A randomized, placebo-controlled, double-blind comparison of amlodipine and atenolol in patients with essential hypertension.

The efficacy and safety of amlodipine (2.5 mg, 5 mg, or 10 mg) once daily was compared with atenolol (50 mg to 100 mg) once daily in patients with mild-to-moderate essential hypertension in a randomized, double-blind, parallel, placebo-controlled study. One hundred and twenty-five patients were randomly allocated at the end of a 4-week run-in placebo period to 8 weeks' double-blind treatment with amlodipine (n = 41), atenolol (n = 43), or placebo (n = 41). The mean changes from baseline in blood pressure 24 h postdose for amlodipine (mean daily dose 8.8 mg) were -12.8/-10.1 mm Hg for supine and -11.5/-9.8 mm Hg for standing blood pressure (P < .001). For atenolol (mean daily dose 83.7 mg) the changes were -11.3/-11.7 mm Hg for supine and -13.3/-12.3 mm Hg for standing blood pressure (P < .001). There were no statistically significant differences between treatments. The responder rates for amlodipine, atenolol, and placebo were 61.1%, 64.9%, and 11.1%, respectively. Determinations taken over the 24-h period at the final visit revealed that amlodipine and atenolol maintained the group mean supine blood pressure at or below 140/90 mm Hg throughout the period of observation; the corresponding time-effect curve for the placebo group was clearly in the hypertensive range. Heart rate was significantly lowered by atenolol only. Both amlodipine and atenolol were well-tolerated. Only one patient was withdrawn because of the development of peripheral edema, arthralgia, and fatigue after treatment with amlodipine. This study demonstrates that once-daily administration of amlodipine or atenolol to mild-to-moderate hypertensive patients was well-tolerated and provided adequate blood pressure control throughout the 24-h dosing interval.

Adolescent↗

PubMed1989

Sustained-release diltiazem: duration of antihypertensive effect.

The antihypertensive activity of a sustained-release preparation of diltiazem (given each 12 hours) was assessed in 96 patients with supine diastolic blood pressure (BP) between 95 and 110 mm Hg in a multicenter, randomized, double-blind, placebo run-in, parallel-group trial comparing optimally titrated doses of diltiazem and placebo. The aim was to assess the onset of action as well as the extent and variability of BP control of this formulation during the 12-hour interval. Diltiazem was titrated from 120 mg bid to 180 mg bid as necessary to lower BP. At baseline, on the first day of titration, and at the end of 8 weeks, BP was evaluated at 0, 1, 2, 3, 4, 5, 6, 8, 10, and 12 hours after dosing. The onset of action was within 2 hours, and the effect was maintained throughout the 12-hour period. Mean BP for the diltiazem group at baseline was 154/101 mm Hg. At week 8, BP was 148/93 mm Hg at hour "0" (P less than .02 and P = .0001 for systolic and diastolic BP vs. placebo), 139/84 mm Hg at the nadir at hour 5 (P = .0001), and 149/91 mm Hg at the end of the 12-hour period (P less than .02 and P = .0001 for systolic and diastolic BP). Diltiazem was significantly more effective than placebo (P = .0001) with 50% of patients controlled to a diastolic pressure of less than 90 mm Hg at 7 of the 10 evaluation points, including the evaluation point of 12 hours post-dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1988

Metabolic effects of antihypertensive therapy with a calcium antagonist.

The effect of diuretics to increase serum glucose, low-density lipoprotein cholesterol and triglycerides, as well as the adverse changes in triglycerides and high-density lipoprotein cholesterol produced by nonselective beta blockers, have been largely ignored in the treatment of hypertension. However, a number of trials have shown that reductions in serum lipids can alter cardiovascular mortality. Calcium antagonists have become major drugs in the treatment of hypertension, and some data suggest that calcium antagonists may increase serum glucose levels. Significantly less data on lipid effects have been published. Lipid and glucose effects were examined in an 8-week antihypertensive study using a sustained-release preparation of diltiazem titrated from 240 to 360 mg/day in a twice-daily regimen in a randomized, double-blind, placebo-controlled parallel trial in 96 patients. Average supine blood pressure at week 8 was 156/98 mm Hg, standing blood pressure with placebo 152/100 mm Hg, and with diltiazem 147/91 and 144/93 mm Hg. There were no statistically significant changes in serum lipids or glucose in the diltiazem or placebo group or between the groups. Mean values (mg/dl) at baseline and week 8 in the diltiazem group were, respectively, for cholesterol 215 and 218, high-density lipoprotein cholesterol 50 and 51, low-density lipoprotein cholesterol 128 and 133, triglycerides 169 and 175, and glucose 113 and 110. Thus, this large and placebo-controlled study shows that diltiazem is among the antihypertensives with no adverse long-term lipid or glucose effects.

Blood Glucose↗

PubMed1988

A randomized placebo-controlled comparison of amlodipine and atenolol in mild to moderate systemic hypertension.

Amlodipine, a new long-acting dihydropyridine calcium antagonist, was compared with placebo and atenolol in 125 patients with mild to moderate systemic hypertension [supine diastolic blood pressure (DBP) 90-114 mm Hg]. Patients received placebo for 4 weeks, followed by a random allocation to an 8-week double-blind, once-daily treatment with amlodipine (n = 41), atenolol (n = 43), or placebo (n = 41). The changes in 24-h post-dose blood pressure (BP) from baseline to final visit for amlodipine (mean daily dose 8.8 mg, range 5-10 mg) were -12.8 +/- 2.0/ -10.1 +/- 1.2 mm Hg in supine BP and -11.5 +/- 2.3/-9.8 +/- 1.1 mm Hg in standing BP (p less than 0.001); for atenolol (mean daily dose 83.7 mg, range 50-100 mg), the changes from baseline were -11.3 +/- 2.3/-11.7 +/- 1.3 mm Hg in supine BP and -13.3 +/- 3.1/-12.3 +/- 1.5 mm Hg in standing BP (p less than 0.001); for placebo, the changes from baseline were -0.9 +/- 2.8/-3.5 +/- 0.9 mm Hg in supine BP and -1.6 +/- -2.6/-4.0 +/- 1.0 mm Hg in standing BP. In the study, goal response was defined as a supine DBP of less than 90 mm Hg or its decrease by greater than or equal to 10 mm Hg. The response rates were similar for atenolol (65%) and amlodipine (61%). Both active therapies were significantly more effective than placebo. Heart rate was significantly lowered by atenolol only.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1987

Antihypertensive effectiveness of the nifedipine gastrointestinal therapeutic system.

The results of a multicenter trial conducted in order to determine the therapeutic efficacy of the gastrointestinal therapeutic system (GITS) formulation of nifedipine in comparison with hydrochlorothiazide and placebo in the management of mild to moderate essential hypertension are presented. During a one-week wash-out phase, antihypertensive therapy was discontinued in all patients. After a three-week single-blind placebo period, eligible patients were randomly assigned in a double-blind fashion to one of three treatment groups for a one-week titration period and a nine-week efficacy period. Patients received either nifedipine GITS, 30 or 60 mg daily; hydrochlorothiazide, 25 or 50 mg daily; or placebo. Sitting and standing blood pressures decreased by an average 11.6/10.4 and 10.8/10.8 mm Hg, respectively, with nifedipine GITS therapy, and 14.8/10.8 and 14.3/8.2 mm Hg, respectively, with hydrochlorothiazide therapy. Compared with placebo, these changes were highly significant for both sitting (p less than or equal to 0.005) and standing (p less than or equal to 0.02) measurements. Heart rate remained essentially unchanged in all three groups. It was therefore concluded that monotherapy with nifedipine GITS, at doses of 30 or 60 mg given once daily, effectively reduces blood pressure in patients with hypertension to a degree comparable with that seen in hydrochlorothiazide therapy.

Adult↗

PubMed1987

A double-blind parallel trial to assess the efficacy of doxazosin, atenolol and placebo in patients with mild to moderate systemic hypertension.

The antihypertensive and lipid effects of doxazosin and atenolol were compared in a 10-week, double-blind, parallel, placebo-controlled study. The 129 adults enrolled had mild to moderate hypertension (average supine diastolic blood pressures for doxazosin, atenolol and placebo were 100.6, 101.0 and 99.7 mm Hg, respectively). Patients were randomly assigned to treatment with doxazosin, 1 to 16 mg daily, atenolol, 50 to 100 mg daily or placebo. Among 114 patients included in the efficacy analysis, standing blood pressure (systolic/diastolic) changed by -13/-11 mm Hg with doxazosin (n = 37), -12/-12 mm Hg with atenolol (n = 39) and +1/-1 mm Hg with placebo (n = 38). Mean reductions in blood pressure for doxazosin and atenolol were significantly greater than those for placebo (p less than 0.01), although no statistically significant differences between the active agents were noted. Serum lipid measurements were evaluable for 116 patients, and the 38 doxazosin-treated patients in this group experienced reductions in total cholesterol, total triglyceride and very low density lipoprotein cholesterol levels. Both doxazosin and atenolol demonstrated comparable acceptance profiles. Doxazosin is an effective hypotensive agent with beneficial effects on serum lipid levels.

Adrenergic alpha-Antagonists↗

PubMed1986

Monotherapy of mild hypertension with nifedipine.

The effectiveness of nifedipine as first-line monotherapy for mild diastolic hypertension (range: 95 to 105 mm Hg) was tested in this placebo-controlled, double-blind, randomized trial. Fifty-six patients were enrolled and, after titration of the placebo or active drug, they were followed for 12 weeks. Significant declines in the sitting systolic and diastolic pressures of -19 +/- 4 mm Hg (standard error) and -13 +/- 2 mm Hg, respectively, were observed during this follow-up period. Overall, 75 percent of patients receiving active drug had diastolic pressures less than or equal to 90 mm Hg at the last treatment visit. Heart rate was not significantly changed in the sitting position during the treatment period, and the majority of patients (75 percent) showed a response to nifedipine doses of 10 or 20 mg orally three times daily in the capsule form. The levels of the systolic and diastolic pressures at entry were not predictive of the dose of nifedipine required for effective blood pressure control.

Adult↗

PubMed1983

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↗

PubMed1982

Mercury in takeaway fish in New Zealand.

Analysis of samples of takeaway fish cooked in batter collected in 1977 showed mercury concentrations in the fish flesh up to 4.4 micrograms/g; the highest concentrations were found in shark. The overall mean value found for the south Auckland areas was 0.72 microgram/g. At this level, the WHO provisional tolerable mercury intake for an adult would be supplied by approximately one mean (two pieces) per day of takeaway fish. Children eating similar sized meals would attain the tolerable mercury intake with one meal every second day.

Adult↗

PubMed1969