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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Twenty-seven patients with mild to moderate essential hypertension were randomized to receive therapy with either hydrochlorothiazide or diltiazem. After a placebo run-in period of 2 weeks, patients received increasing doses of either drug for 14 weeks. Those in whom hypertension was effectively controlled continued for 26 weeks of total treatment. Those not controlled, i.e. blood pressure greater than 140/90 mm Hg or less than 10 mm Hg reduction of pressure, were unblinded and crossed over to therapy with both drugs. Eleven of 14 patients (79%) were effectively treated with diltiazem alone, and 8 of 13 patients (62%) were effectively treated with hydrochlorothiazide alone. Supine blood pressures fell from 152 +/- 5/97 +/- 1 to 142 +/- 4/87 +/- 3 mm Hg in the 11 patients treated with diltiazem, from 152 +/- 2/99 +/- 1 to 134 +/- 3/88 +/- 2 mm Hg in the 8 patients treated with hydrochlorothiazide, and from 151 +/- 4/104 +/- 3 to 140 +/- 5/92 +/- 1 mm Hg in the 8 patients who received both drugs (p less than 0.01 for each group). Diltiazem patients had significant increases in alkaline phosphatase and urinary magnesium. Hydrochlorothiazide patients had increases in serum uric acid, serum globulin, CO2 content, and plasma renin activity. Serum potassium, serum chloride, urinary osmolality, and urinary calcium decreased after treatment with hydrochlorothiazide. Patients receiving both drugs had increases in serum glucose, serum BUN, serum uric acid, serum globulin, and CO2 content. These patients had decreased serum chloride and urinary calcium. Diltiazem monotherapy was comparable to hydrochlorothiazide in efficacy of lowering blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Renal-metabolic consequences of antihypertensive therapy with diltiazem versus hydrochlorothiazide. 332 Jul 20

Whole-day ambulatory monitoring is used for diagnosing hypertension and for judging response to treatment. We evaluated both of these properties in an antihypertensive trial with the calcium channel blocker diltiazem hydrochloride. Measured by a conventional sphygmomanometer, systolic and diastolic blood pressures fell significantly in patients who received diltiazem, whereas no consistent changes occurred in those who received placebo. Administration of the drug also decreased systolic and diastolic blood pressures evenly throughout the day, as determined by automated monitoring. The 15 diltiazem-treated patients were subdivided into those whose clinically diagnosed hypertension was confirmed by pretreatment blood pressure monitoring (24-hour average diastolic blood pressure, greater than or equal to 90 mm Hg; n = 9) and those whose 24-hour blood pressures failed to meet this criterion (n = 6). Diltiazem therapy decreased average whole-day blood pressures by 18/13 mm Hg in the hypertensives but by only 0/1 mm Hg in the others. Thus, whole-day blood pressure monitoring strengthens antihypertensive trials by documenting efficacy and duration of treatment. In addition, it enhances the diagnosis of hypertension, thereby identifying those patients in whom treatment seems justified.
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PMID:Characterization of antihypertensive therapy by whole-day blood pressure monitoring. 337 59

Diltiazem plasma clearance was studied in normotensive (NR) and spontaneous hypertensive rats (SHR), either following intravenous bolus administration of 3 mg/kg (CLiv), or after 25 min of intravenous infusion (CL25) at different dose levels (1, 2, 4, and 8 mg/kg/30 min in NR; 0.5, 1, 2, and 4 mg/kg/30 min in SHR). The diltiazem pharmacokinetic profile fit a two-compartment open model better, both in NR and SHR. The CLiv of diltiazem was significantly higher in NR than in SHR. Following infusion, diltiazem plasma clearance increased for high levels of infused dose in NR and in SHR. For each level of dose, CI25 was significantly higher in NR than in SHR. For both groups of animals, CI25 values were significantly higher than their respective CIiv values. These results show the influence of hypertension on the pharmacokinetic characteristics of diltiazem, as well as the effect of its own vasodilator action. An increase in diltiazem clearance values may be due to an increase in hepatic blood flow that is a result of its vasodilator action.
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PMID:Comparative diltiazem plasma clearance in normotensive and hypertensive rats. 344 Sep 27

A multicenter, randomized, placebo-controlled, parallel group study of diltiazem in essential hypertension was carried out in 77 patients (40 diltiazem, 37 placebo) with stable supine diastolic blood pressure (BP) between 95 and 110 mm Hg. Patients were withdrawn from previous antihypertensive therapy for at least 4 weeks, titrated to the optimal dose, and followed for a total of 12 weeks during therapy. A diltiazem dose of 360 mg/day was required in 85% of the patients. Average BP in all positions was significantly (p less than 0.0001) reduced by diltiazem compared with placebo. With diltiazem, average supine BP fell from 156/100 mm Hg at baseline to 141/87 at end titration and 145/90 mm Hg at week 12, whereas average standing BP fell from 152/101 mm Hg to 136/90 and 143/91 mm Hg, respectively, at those times. There was no significant change in heart rate at week 12. Diltiazem tended to be more effective in older patients, but caused no increase in orthostatic BP drop. There were no statistically significant changes in BP in the placebo group. Two patients receiving placebo and 1 patient receiving diltiazem discontinued therapy as a result of adverse effects, and overall, side effects were only slightly more common with diltiazem treatment. Thus, diltiazem was effective and well tolerated single therapy for mild to moderate systemic hypertension and appears to compare favorably to most agents being used.
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PMID:Diltiazem as monotherapy for systemic hypertension: a multicenter, randomized, placebo-controlled trial. 351 60

The renal effects of the calcium entry-blocking drugs diltiazem, nifedipine, nitrendipine, nicardipine and verapamil are reviewed. Although nifedipine may acutely increase plasma renin activity, most of the calcium entry blockers have no sustained effect on any of the components of the renin-angiotensin-aldosterone system. Although all of the calcium entry blockers effectively lower blood pressure, none adversely affects renal function: Glomerular filtration rate and effective renal plasma flow are maintained. Diltiazem may increase glomerular filtration rate via attenuation of the intrarenal effects of angiotensin II or norepinephrine. Although all of the calcium entry blockers acutely increase salt and water excretion, most of the calcium entry blockers have no clinically sustained effect on salt and water excretion; serum electrolytes, urinary sodium and potassium excretion, body fluid composition and body weight are usually unchanged. Calcium entry blockers can be expected to assume a prominent role in the treatment of hypertension because of their ability to lower blood pressure while preserving renal perfusion and function.
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PMID:Short- and long-term effects of calcium entry blockers on the kidney. 354 86

Both traditional and newer treatments of essential hypertension are discussed in relation to kidney function and renal perfusion. In essential hypertension, renal vascular resistance is routinely increased and renal blood flow is often decreased. Reduced sodium intake as a form of therapy will cause a decrease in both renal blood flow and glomerular filtration, most likely due to an angiotensin-induced renal vasoconstriction caused by the reactive increase in renin release. Treatment with diuretics produces the same effects, also angiotensin-mediated. The addition of a beta-adrenergic blocking agent to prevent renin release may be a good choice, but individual agents within this class must be examined for direct renal vasoconstriction. The effects of "nonspecific" vasodilators on renal perfusion and renal sodium handling vary with the patient but may produce antinatriuresis, sodium retention and decrease in glomerular filtration. Studies with calcium antagonists have shown promising results. Nifedipine studies show a substantial increase in renal plasma flow, a well-maintained glomerular filtration rate and a brisk diuresis and natriuresis. However, patients with the lowest baseline renal flow do not show these benefits. Diltiazem has shown a potentiated renal vascular response in normotensive patients of hypertensive parents. Angiotensin converting enzyme inhibitors such as captopril and enalapril have produced increased renal blood flow and well-maintained glomerular filtration in patients with essential hypertension. The agents available for treating hypertension have improved dramatically in the past decade. A salutary effect on the kidney will remain high on the list of important characteristics to be considered in choosing one of these agents.
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PMID:Vasodilators, antihypertensive therapy and the kidney. 368 6

The antihypertensive effect of diltiazem (180-270 mg/day) and nifedipine (40-60 mg/day) in slow-release forms was assessed over 8 weeks in a double-blind parallel study in 40 subjects with essential hypertension at rest and during exercise. Blood pressure was comparably reduced in both groups at rest as well as during exercise. The responder rates (greater than or equal to 10% reduction in diastolic blood pressure) after 8 weeks of therapy were 53% at rest and 75% during exercise in the diltiazem group and 78% and 50%, respectively, in the nifedipine group. Diltiazem decreased heart rate by 8% (p less than 0.01), while nifedipine did not affect it. As a consequence, myocardial oxygen consumption, as judged by the pressure-rate product, was reduced by diltiazem. Resting plasma norepinephrine levels were increased significantly after 8 weeks of diltiazem therapy. Plasma epinephrine, renin, aldosterone, glucose, insulin, and lactate and routine laboratory parameters were unchanged at the end of the study. No significant changes in total cholesterol and triglyceride levels were observed after 8 weeks. Whereas therapy with diltiazem resulted in an 8% fall in low density lipoprotein cholesterol after 8 weeks (p less than 0.05), nifedipine induced a drop in very low density lipoprotein cholesterol (p less than 0.05) after 8 weeks of therapy. We conclude that both diltiazem and nifedipine are effective antihypertensive agents lacking undesirable metabolic side effect. Diltiazem, however, had the advantage of lowering heart rate and myocardial oxygen consumption.
Hypertension 1986 Oct
PMID:Antihypertensive and metabolic effects of diltiazem and nifedipine. 375 24

Both beta-blocking and calcium channel-blocking drugs are being used with increasing frequency as initial therapy for essential hypertension. The present study was designed to compare the antihypertensive effects of a beta-blocking drug, propranolol, with a calcium channel-blocking drug, diltiazem, at rest and during upright bicycle exercise and to determine whether exercise capacity is altered by these therapies. Twenty-one patients with uncomplicated systemic hypertension and a diastolic blood pressure (BP) of 95 to 110 mm Hg without medication were randomly assigned to propranolol or diltiazem therapy in a double-blind manner. The total daily dosages were titrated as needed, from 160 to 480 mg of propranolol (mean 371 mg) and 120 to 360 mg of diltiazem (mean 307 mg) over 12 weeks, and the titrated dose was maintained for 4 additional weeks. Both drugs significantly reduced supine BP (from 149 +/- 14/101 +/- 4 to 136 +/- 17/89 +/- 10 mm Hg with propranolol and from 157 +/- 14/103 +/- 4 to 144 +/- 13/93 +/- 8 with diltiazem. Only diltiazem reduced BP during submaximal exercise, but both agents produced significant responses during maximal exercise. Diltiazem had no effect on maximal heart rate, exercise duration or O2 uptake, whereas propranolol reduced maximal VO2 from 27 +/- 6 to 22 +/- 6 ml/min/kg (p less than 0.01) and also shortened duration of exercise. Propranolol, despite its effects on heart rate, maintained the workload VO2 relation at submaximal loads, suggesting an increased oxygen delivery. However, these adaptive mechanisms appear to be insufficient during maximal effort.
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PMID:Diltiazem versus propranolol in essential hypertension: responses of rest and exercise blood pressure and effects on exercise capacity. 381 8

A number of studies have shown short term hemodynamic and symptomatic improvement in patients with essential hypertension under treatment with diltiazem. The long-term efficacy of the oral calcium antagonist, diltiazem, remain to be established in patient studies. We evaluated this drug in 70 patients with WHO classification 1-3 hypertension. Diltiazem was tested alone in 25 patients, in combination with diuretics in 14 patients and other drugs in 31 patients with essential hypertension. The fall in blood pressure after oral diltiazem was maximum with 24 weeks and then the fall continued steadily with significant improvement as judged by subjective patients impression in each group. The efficacy ratio of diltiazem was 57.1% in remarkably effective cases, 22.9% in effective, 10% in moderately effective and 10% in not effective cases. And this efficacy ratio was most prominent in other drugs concomitant group, followed by the diltiazem monotherapy group and in the diuretic concomitant use group. We concluded the oral calcium antagonist, diltiazem, is effective in patients with essential hypertension, providing significant blood pressure and symptomatic benefit with long-term treatment.
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PMID:Effect of diltiazem hydrochloride in essential hypertension. 388 66

Diltiazem is an orally and intravenously active calcium channel blocking agent shown to be an effective and well-tolerated treatment for stable angina and angina due to coronary artery spasm. Its efficacy in these diseases has generally been similar to that of nifedipine or verapamil - alternative calcium channel blockers with which diltiazem has many electrophysiological, haemodynamic, and antiarrhythmic similarities. The antianginal mechanism of diltiazem cannot be precisely described; however, it appears to increase myocardial oxygen supply and decrease myocardial oxygen demand, mainly by coronary artery dilatation and/or via both direct and indirect haemodynamic alterations. Diltiazem has also shown substantial efficacy in the treatment of unstable angina, hypertension, and supraventricular tachyarrhythmias, but further study is necessary before its place in the treatment of these diseases may be clearly established. Although headache due to peripheral vasodilatation and depression of atrioventricular nodal conduction may be troublesome, side effects occur in only 2 to 10% of patients receiving diltiazem and are generally minor in nature. Thus, diltiazem offers a worthwhile alternative to other agents currently available for the treatment of angina pectoris. Although the infrequency of serious side effects may offer an advantage, its relative place in therapy compared with that of other calcium channel blockers remains to be clarified.
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PMID:Diltiazem. A review of its pharmacological properties and therapeutic efficacy. 389 2


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