Resistance to antihypertensive medication as predictor of renal artery stenosis: comparison of two drug regimens.
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BACKGROUND: Renal artery stenosis is among the most common curable causes of hypertension. The definitive diagnosis is made by renal angiography, an invasive and costly procedure. The prevalence of renal artery stenosis is less than 1% in non-selected hypertensive patients but is higher when hypertension is resistant to drugs. OBJECTIVE: To study the usefulness of standardised two-drug regimens for identifying drug-resistant hypertension as a predictor of renal artery stenosis. DESIGN AND SETTING: Prospective cohort study carried out in 26 hospitals in The Netherlands. PATIENTS: Patients had been referred for analysis of possible secondary hypertension or because hypertension was difficult to treat. Patients < or =40 years of age were assigned to either amlodipine 10 mg or enalapril 20 mg, and patients >40 years to either amlodipine 10 mg combined with atenolol 50 mg or to enalapril 20 mg combined with hydrochlorothiazide 25 mg. Renal angiography was performed: (1) if hypertension was drug-resistant, ie if diastolic pressure remained > or =95 mm Hg at three visits 1-3 weeks apart or an extra drug was required, and/or (2) if serum creatinine rose by > or =20 micromol/L (> or =0.23 mg/dL) during ACE inhibitor treatment. RESULTS: Of the 1106 patients with complete follow-up, 1022 had been assigned to either the amlodipine- or enalapril-based regimens, 772 by randomisation. Drug-resistant hypertension, as defined above, was identified in 41% of the patients, and 20% of these had renal artery stenosis. Renal function impairment was observed in 8% of the patients on ACE inhibitor, and this was associated with a 46% prevalence of renal artery stenosis. In the randomised patients, the prevalence of renal artery stenosis did not differ between the amlodipine- and enalapril-based regimens. CONCLUSIONS: In the diagnostic work-up for renovascular hypertension the use of standardised medication regimens of maximally two drugs, to identify patients with drug-resistant hypertension, is a rational first step to increase the a priori chance of renal artery stenosis. Amlodipine- or enalapril-based regimens are equally effective for this purpose. (+info)
The effect of the fast of Ramadan on ambulatory blood pressure in treated hypertensives.
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Every year, millions of Moslems throughout the world fast from sunrise till sunset daily during the month of Ramadan, that is, experience repeated cycles of fasting-refeeding. Studies in animal models have shown that repeated cycles of fasting-refeeding may cause or exacerbate hypertension. Changes in sleeping patterns as well as changes in medication timing may also influence ambulatory blood pressure. We undertook this study in order to examine the effect of the Ramadan fast on treated hypertensive subjects. Seventeen hypertensive subjects were examined, and 24-h blood pressure monitoring was carried out twice, before and during the last week of the Ramadan. All continued their medications, which were all once-daily preparations. Twenty-four hour mean blood pressure as well as average awake and average asleep blood pressure were compared. There was no difference between mean blood pressure before and during the Ramadan (138.5 +/- 18.5/77.2 +/- 8.1 mm Hg vs 136.4 +/- 20.4/75.7 +/- 5.9 mm Hg, P-nonsignificant). Blood pressure load also did not differ before and during Ramadan (systolic load 49% vs. 44%, diastolic load 21% vs. 18%, P-nonsignificant). Weight was reduced by 1.4 +/- 1.6 kg (P < 0.002). We conclude, that according to our findings, treated, hypertensive patients may be assured that, with continuation of previous medications, traditional fasting during the month of Ramadan can be safely undertaken. (+info)
Pulse pressure changes with six classes of antihypertensive agents in a randomized, controlled trial.
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Pulse pressure has been more strongly associated with cardiovascular outcomes, especially myocardial infarction and heart failure, than has systolic, diastolic, or mean arterial pressure in a variety of populations. Little is known, however, of the comparative effects of various classes of antihypertensive agents on pulse pressure. In retrospective analyses of the Veterans Affairs Single-Drug Therapy for Hypertension Study, we compared changes in pulse pressure with 6 classes of antihypertensive agents: 1292 men with diastolic blood pressure of 95 to 109 mm Hg on placebo were randomized to receive hydrochlorothiazide, atenolol, captopril, clonidine, diltiazem, prazosin, or placebo. Drug doses were titrated to achieve a goal diastolic blood pressure of <90 mm Hg during a 4- to 8-week medication titration phase. Pulse pressure change (placebo subtracted) was assessed from baseline to the end of the 3-month titration and 1-year maintenance. Mean baseline systolic, diastolic, and pulse pressures were 152, 99, and 53 mm Hg, respectively. Reductions in pulse pressure during titration were greater (P<0.001) with clonidine (6.7 mm Hg) and hydrochlorothiazide (6.2 mm Hg) than with captopril (2.5 mm Hg), diltiazem (1.6 mm Hg), and atenolol (1.4 mm Hg); reduction with prazosin (3.9 mm Hg) was similar to all but clonidine. After 1 year, pulse pressure was reduced significantly more (P<0.001) with hydrochlorothiazide (8.6 mm Hg) than with captopril and atenolol (4.1 mm Hg with both); clonidine (6.3 mm Hg), diltiazem (5.5 mm Hg), and prazosin (5.0 mm Hg) were intermediate. These data show that classes of antihypertensive agents differ in their ability to reduce pulse pressure. Whether these differences affect rates of cardiovascular events remains to be determined. (+info)
Efficacy and tolerability of a fixed-dose combination of telmisartan plus hydrochlorothiazide in patients uncontrolled with telmisartan monotherapy.
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The antihypertensive effects of a telmisartan 80 mg/hydrochlorothiazide (HCTZ) 12.5 mg fixed-dose combination and telmisartan 80 mg monotherapy were compared in patients with a history of mild-to-moderate essential hypertension and inadequate BP control (DBP > or = 90 mm Hg) following 8 weeks of telmisartan monotherapy. At the end of this period, 491 patients (62.9% men; mean age 55.3 years) whose DBP was > or = 90 mm Hg were double-blind randomised to once-daily telmisartan 80 mg/HCTZ 12.5 mg (n = 246) or telmisartan 80 mg (n = 245). Trough (24 h post-dose) clinic BP was measured after 4 and 8 weeks of double-blind therapy. At the end of double-blind treatment, patients receiving telmisartan 80 mg/HCTZ 12.5 mg had significant additional decrements in clinic SBP/DBP over telmisartan 80 mg of -5.7/-3.1 mm Hg (P < 0.01). Most of the additional effect occurred during the first 4 weeks of treatment. The proportion of patients with normalised BP (SBP < 140 mm Hg and DBP < 90 mm Hg) was significantly greater in the telmisartan 80 mg/HCTZ 12.5 mg group than the telmisartan 80 mg group (41.5%vs 26.1%;P < 0.05). Both treatments were well tolerated. The incidence of adverse events was similar except for diarrhoea, which occurred more frequently in the telmisartan 80 mg/HCTZ 12.5 mg group, and oedema, which occurred more frequently in the telmisartan group. Our results indicate that a telmisartan 80 mg/HCTZ 12.5 mg fixed-dose combination confers significant additional BP reductions compared with continuation of telmisartan monotherapy in non-responders. (+info)
A retrospective study of persistence with single-pill combination therapy vs. concurrent two-pill therapy in patients with hypertension.
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CONTEXT: Patients with hypertension often fail to control their blood pressure because they do not comply with pharmacologic therapy. It was hypothesized that a greater percentage of patients receiving a single pill combining an ACE inhibitor and a diuretic would persist with therapy than patients receiving both drugs as separate pills. METHODS: Prescription data were obtained from a large commercial pharmacy benefit manager (PBM). The records of presumably newly diagnosed hypertensive patients for whom lisinopril combined with hydrochlorothiazide in a single pill (lisinopril/HCTZ) was prescribed (n = 1,644) were compared with those of patients for whom lisinopril and a diuretic were prescribed concurrently (n = 624). Likewise, the records of patients for whom enalapril maleate combined with hydrochlorothiazide in a single pill (enalapril/HCTZ) was prescribed (n = 969) were compared with those of patients for whom enalapril maleate and a diuretic were prescribed concurrently (n = 705). Patients were regarded as persisting if they renewed their prescription within three times the number of days supplied by the previous prescription. Patients were followed for one year from the date of the initial prescription. RESULTS: At 12 months, the percentages of patients persisting with lisinopril/HCTZ (68.7 percent) and enalapril/HCTZ (70.0 percent) therapy were 18.8 percent and 21.7 percent greater, respectively, than the percentages of patients persisting with lisinopril plus concurrent diuretic therapy (57.8 percent) or enalapril maleate plus concurrent diuretic therapy (57.5 percent). Statistical significance (p < 0.05) was demonstrated at 6 and 12 months for both comparisons. CONCLUSION: The simplification of a drug regimen by using combination therapy in a single pill for hypertension resulted in significant increases in persistence with prescribed therapy. (+info)
Influence of anti-hypertensive drug treatment on vascular reactivity in spontaneously hypertensive rats.
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1. The effect of prolonged anti-hypertensive drug treatment on the blood pressure of conscious spontaneously hypertensive rats (SH-rats), and of age-matched normotensive Sprague-Dawley rats was determined during the development of hypertension in SH-rats and in the early stages of established hypertension. A comparison of the vascular reactivity to noradrenaline (NA) and 5-hydroxytryptamine (5-HT) was also made in isolated perfused mesenteric artery preparations from treated and control SH- and Sprague-Dawley rats. 2. Chronic treatment from age 4 to 16 weeks with hydrallazine alone, or a combination of hydrallazine/hydrochlorothiazide/reserpine, ad libitum in the drinking water, prevented the development of hypertension in SH-rats and also reduced the vascular reactivity to NA and 5-HT in isolated vessel preparations from treated compared to control rats. 3. Similar drug treatments started in early established hypertension reduced blood pressure in SH-rats over the 12 week treatment period (from age 8 to 20 weeks) without affecting vascular reactivity to NA and 5-HT in the isolated vessel preparation. 4. Drug treatments had little effect on blood pressure of age-matched Sprague-Dawley rats and no effect on vascular reactivity to NA and 5-HT in the isolated perfused mesenteric artery preparation from treated compared to control rats. 5. These results indicate that the development of increased vascular reactivity and of hypertension in SH-rats occurs simultaneously and, therefore, the vascular changes may be a consequence of the structural changes induced by the raised blood pressure. 6. In established hypertension, no regression of vascular changes was observed despite prolonged reduction of blood pressure. The role of an increased vascular reactivity in the maintenance of hypertension is therefore questionable. (+info)
Effect of two antihypertensive combinations on metabolic control in type-2 diabetic hypertensive patients with albuminuria: a randomised, double-blind study.
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The objective of this study was to compare, at equal blood pressure (BP) reduction, the effect of two different combinations on metabolic control and albuminuria in type 2 diabetic hypertensive patients with albuminuria. This was a prospective, randomised, double-blind, parallel, controlled trial carried out in 11 Spanish hospitals. A total of 103 type 2 diabetic patients with stable albuminuria and BP not controlled on monotherapy were randomised of which 93 finished the study. After a 4-week single-blind placebo period, patients were randomised to verapamil SR/trandolapril 180/2 mg (VT) or to enalapril/hydroclorothiazide 20/12.5 mg (EH). Treatment duration was 6 months. The main outcome measures were changes in BP, 24-h albuminuria, blood glucose and glycated haemoglobin. Overall BP was significantly reduced from 157.3 +/- 12.0/98.3 +/- 6.4 mm Hg to 140.5 +/- 14.5/86.1 +/- 8.2 mm Hg (P < 0.001) and albuminuria significantly decreased from 508.6 +/- 693.8 mg/24 h to 253.4 +/- 517.2 mg/24 h (P < 0.001), both without significant differences between treatments. Glycated haemoglobin was not modified on VT: baseline, 5.91 +/- 1.43%; end of treatment, 5.94 +/- 1.62%, but increased on EH: baseline, 5.96 +/- 1.25%; final, 6.41 +/- 1.51%, (ANOVA interaction P = 0.040). At the end of the study, a blood glucose <126 mg/dL was attained in 72.7% of the VT group-improving in 29.5% and worsening in 6.8% of patients (P = 0.021)-and in 50% of the EH group, 13.6% of patients improved and 11.4% worsened (P = 1.000). There were no changes in body weight, serum creatinine, uric acid, potassium, cholesterol, tryglicerides and serum albumin. In hypertensive type 2 diabetic patients not controlled on monotherapy, both treatments similarly reduced albuminuria. The combination verapamil/ trandolapril seems to allow a better metabolic control than enalapril/hydroclorothiazide. (+info)
Transient global amnesia associated with cardiac arrhythmia and digitalis intoxication.
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A 54-year-old woman with transient global amnesia (TGA) was found to have digitalis-induced bradyarrhythmia with atrioventricular dissociation. The amnesia cleared only upon resolution of the arrhythmia. Cardiac arrhythmia has been postulated as a cause, but TGA in the setting of cardiac arrhythmia has not been documented previously. Cardiac arrhythmia should be excluded in patients with TGA, and TGA, a syndrome diagnosed on clinical grounds alone, must be recognized as one possible manifestation of treatable, potentially serious cardiac or cerebrovascular disease. (+info)