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1.
Arch Intern Med ; 158(15): 1681-91, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9701103

RESUMO

BACKGROUND: In 1989, the European Working Party on High Blood Pressure in the Elderly started the double-blind, placebo-controlled, Systolic Hypertension in Europe Trial to test the hypothesis that antihypertensive drug treatment would reduce the incidence of fatal and nonfatal stroke in older patients with isolated systolic hypertension. This report addresses whether the benefit of antihypertensive treatment varied according to sex, previous cardiovascular complications, age, initial blood pressure (BP), and smoking or drinking habits in an intention-to-treat analysis and explores whether the morbidity and mortality results were consistent in a per-protocol analysis. METHODS: After stratification for center, sex, and cardiovascular complications, 4695 patients 60 years of age or older with a systolic BP of 160 to 219 mm Hg and diastolic BP less than 95 mm Hg were randomized. Active treatment consisted of nitrendipine (10-40 mg/d), with the possible addition of enalapril maleate (5-20 mg/d) and/or hydrochlorothiazide (12.5-25 mg/d), titrated or combined to reduce the sitting systolic BP by at least 20 mm Hg, to below 150 mm Hg. In the control group, matching placebo tablets were employed similarly. RESULTS: In the intention-to-treat analysis, male sex, previous cardiovascular complications, older age, higher systolic BP, and smoking at randomization were positively and independently correlated with cardiovascular risk. Furthermore, for total (P = .009) and cardiovascular (P = .09) mortality, the benefit of antihypertensive drug treatment weakened with advancing age; for total mortality (P = .05), the benefit increased with higher systolic BP at entry, while for fatal and nonfatal stroke (P = .01), it was most evident in nonsmokers (92.5% of all patients). In the perprotocol analysis, active treatment reduced total mortality by 24% (P = .05), reduced all fatal and nonfatal cardiovascular end points by 32% (P<.001), reduced all strokes by 44% (P = .004), reduced nonfatal strokes by 48% (P = .005), and reduced all cardiac end points, including sudden death, by 26% (P = .05). CONCLUSIONS: In elderly patients with isolated systolic hypertension, stepwise antihypertensive drug treatment, starting with the dihydropyridine calcium channel blocker nitrendipine, improves prognosis. The per-protocol analysis suggested that treating 1000 patients for 5 years would prevent 24 deaths, 54 major cardiovascular end points, 29 strokes, or 25 cardiac end points. The effects of antihypertensive drug treatment on total and cardiovascular mortality may be attenuated in very old patients.


Assuntos
Anti-Hipertensivos/uso terapêutico , Transtornos Cerebrovasculares/prevenção & controle , Hipertensão/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Transtornos Cerebrovasculares/epidemiologia , Método Duplo-Cego , Enalapril/uso terapêutico , Feminino , Seguimentos , Humanos , Hidroclorotiazida/uso terapêutico , Hipertensão/epidemiologia , Incidência , Masculino , Pessoa de Meia-Idade , Nitrendipino/uso terapêutico , Prognóstico , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo
2.
Hypertension ; 20(5): 601-5, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1428110

RESUMO

The relation between stroke mortality and blood pressure was investigated in 10,186 hypertensive patients followed up in the Department of Health Hypertension Care Computing Project for an average of 9 years. An untreated blood pressure measurement was available in 3,472 men and 3,405 women. The age-adjusted risk of stroke death increased by 1% for every 1 mm Hg increase in untreated systolic blood pressure. The relative hazard rate was 1.014 (95% confidence interval [CI], 1.007, 1.021) in men and 1.009 (1.003, 1.016) in women. The corresponding increases for 1 mm Hg for untreated diastolic blood pressure were almost 3% in men and again 1% in women (relative hazard rate 1.026 [95% CI, 1.014, 1.038] in men and 1.010 [1.000, 1.021] in women). Treated blood pressure measurements were available in 3,073 men and 3,148 women. Stroke mortality increased by 2% for a 1 mm Hg increase in treated systolic pressure and 3% for the corresponding increase in diastolic blood pressure. The relation between stroke mortality and blood pressure was similar over and under the age of 65, although the increase in mortality with pressure was greater for treated diastolic blood pressure in women under the age of 65 than over this age. There was no evidence for a J-shaped relation between stroke mortality and either systolic or diastolic pressure in men. In women there was a suggestion of such a relation, but since this relation was also observed for untreated pressures, any increase in risk at lower pressures is unlikely to be a result of treatment.


Assuntos
Pressão Sanguínea , Transtornos Cerebrovasculares/mortalidade , Transtornos Cerebrovasculares/etiologia , Feminino , Humanos , Hipertensão/complicações , Hipertensão/fisiopatologia , Hipertensão/terapia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores Sexuais
3.
Hypertension ; 32(3): 410-6, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9740604

RESUMO

In the double-blind Systolic Hypertension in Europe (Syst-Eur) Trial, active treatment was initiated with nitrendipine (10 to 40 mg/d) with the possible addition of enalapril (5 to 20 mg/d) and/or hydrochlorothiazide (12.5 to 25 mg/d) titrated or combined to reduce sitting systolic blood pressure by at least 20 mm Hg to <150 mm Hg. In the control group, matching placebos were used similarly. In view of persistent concerns about the use of calcium channel blockers as first-line antihypertensive drugs, this report explored to what extent nitrendipine, administered alone, prevented cardiovascular complications. Age at randomization averaged 70.2 years and systolic/diastolic blood pressure 173.8/85.5 mm Hg. Of 2398 actively treated patients, 1327 took only nitrendipine (average dose, 23.4 mg/d), and 1042 progressed to other treatments including nitrendipine (n=757; 35.7 mg/d), enalapril (n=783; 13.4 mg/d), and/or hydrochlorothiazide (n=294; 21.0 mg/d). Compared with the whole placebo group (n=2297), patients receiving monotherapy with nitrendipine had 25% (P=0.05) fewer cardiovascular end points, and those progressing to other active treatments showed decreases (P

Assuntos
Bloqueadores dos Canais de Cálcio/administração & dosagem , Enalapril/administração & dosagem , Hidroclorotiazida/administração & dosagem , Hipertensão/tratamento farmacológico , Nitrendipino/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/mortalidade , Método Duplo-Cego , Quimioterapia Combinada , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Sístole
4.
J Hypertens ; 7(1): 63-8, 1989 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2651517

RESUMO

We assessed the relative contributions of raised cardiac output and increased peripheral resistance to elevation and lability of blood pressure in patients with borderline and sustained hypertension. Ninety-five untreated patients were admitted to hospital for assessment. Using Doppler ultrasound, linear cardiac output was measured as minute distance on the day of admission and 24 h later; blood pressure was measured at the same times, enabling calculation of linear resistance (analogous to peripheral vascular resistance). In sustained, but not borderline, hypertension linear resistance was increased at the first measurement (+ 36%, P less than 0.001), but mean minute distance did not differ significantly from normal in either group. Between the first and second measurements in borderline and sustained hypertension there were significant falls of mean blood pressure (-9%, P less than 0.001 and -4%, P less than 0.01). In borderline, but not sustained, hypertension there was an associated fall of linear resistance (-11%, P less than 0.05); in neither group was there a significant change of minute distance. Both elevation and lability of blood pressure in borderline and sustained hypertension are due more to changes of peripheral resistance than to changes of cardiac output.


Assuntos
Débito Cardíaco , Hipertensão/diagnóstico , Adolescente , Adulto , Idoso , Feminino , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Ultrassonografia , Resistência Vascular
5.
J Hypertens ; 5(4): 457-60, 1987 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2822797

RESUMO

Enalapril in single doses of 5 and 10 mg and atenolol in a single dose of 50 mg were given to 16 hypertensive patients on long-term treatment with bendrofluazide, 5 mg daily, in a double-blind randomized crossover placebo controlled study. Both doses of enalapril and atenolol produced similar effects on blood pressure. The mean maximal reduction in blood pressure from baseline with all three active treatments was approximately 32/18 mmHg both supine and standing and occurred on average at 6 h after tablet ingestion. Both supine and standing heart rate fell significantly after atenolol, but no significant change occurred after enalapril. This study establishes that 5 mg enalapril is the maximal starting dose that need be used in hypertensive patients already on diuretic treatment. Even this dose may be hazardous in some patients. The study also serves to emphasize that such combination-therapy studies should be carried out at an early stage in drug development, prior to widespread prescription to patients, in order to avoid unnecessary overdosage with new agents.


Assuntos
Atenolol/uso terapêutico , Bendroflumetiazida/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Enalapril/uso terapêutico , Hipertensão/tratamento farmacológico , Adulto , Idoso , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão/metabolismo , Masculino , Pessoa de Meia-Idade , Distribuição Aleatória
6.
J Hypertens ; 8(4): 377-81, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2160495

RESUMO

We compared blood pressure recordings made with the A&D UA-751 semi-automated cuff-oscillometric sphygmomanometer (A&D Co. Ltd, Tokyo, Japan) and with a conventional Hawksley random-zero mercury sphygmomanometer (Hawksley and Sons Ltd, Lancing, UK). Simultaneous single-arm recordings were obtained in duplicate with both devices in 200 subjects having blood pressure in the ranges 92-221/51-121 mmHg. The measurements obtained by three observers using the Hawksley sphygmomanometer were compared with recordings from two A&D UA-751 devices. In most cases, there was an acceptable level of agreement between the results, according to the criteria suggested by the Association for the Advancement of Medical Instrumentation (range of differences systolic: mean - 0.9 to 1.4 mmHg, s.d. 4.6-9.8 mmHg; diastolic: mean - 0.6 to 1.3 mmHg, s.d. 2.9-5.1 mmHg), although there were sizeable discrepancies in individual subjects. Thus the A&D UA-751 device appears to be an acceptable alternative to a conventional sphygmomanometer; it should be suitable for routine clinical and limited research use, including intermittent home blood pressure recording.


Assuntos
Determinação da Pressão Arterial/instrumentação , Humanos
7.
J Hypertens ; 8(7): 599-605, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2168450

RESUMO

Adequate evaluation of automated sphygmomanometers, in terms of safety, accuracy, mechanical reliability, patient acceptability and ability to record ambulatory blood pressure is essential before these devices are used in clinical practice and in clinical trials. We have evaluated the accuracy and performance of the A & D TM-2420 automated sphygmomanometer, an auscultatory device designed for ambulatory blood pressure recording. Four devices were tested for accuracy by simultaneous comparison against two experienced observers using standard mercury column sphygmomanometers. Two of these devices developed faults that precluded complete evaluation. One of the remaining devices met and one failed to meet the somewhat liberal criteria for accuracy recommended by the American Association for the Advancement of Medical Instrumentation, the current standard for evaluation (mean difference of less than or equal to 5 mmHg and standard deviation of differences less than or equal to 8 mmHg). The mean differences (standard deviation of differences) between observers for simultaneous triplicate observations of systolic/diastolic pressure in 50 subjects, including 35 hypertensives, were 0.8 (3.0)/-0.6 (2.4) mmHg. In comparison, the differences between each device and each observer were: device 11, observer 1, -6.4 (5.4)/-6.3 (9.9); device 11, observer 2, -5.6 (4.7)/-7.0 (10.4); device 12, observer 1, -4.9 (5.2)/-4.0 (7.5); device 12, observer 2, -4.1 (4.9)/- -4.5 (7.7) mmHg. Ambulatory trials were carried out with a further 10 devices. Of these, seven developed faults requiring their return to the supplier. Numerous additional problems were encountered with microphones, cuffs, leads and connections, the processing unit, error algorithms and data-handling software. The device was not capable of making truly ambulatory recordings. We do not confirm the previously favourable, but limited, evaluation of this device. We stress the vital importance of subjecting a number of devices to benchtesting for accuracy, and the need to undertake extensive 'field' testing before any devices can be considered suitable for ambulatory recording. Exercise testing under laboratory conditions is not an adequate substitue for true ambulatory evaluation.


Assuntos
Monitores de Pressão Arterial/normas , Hipertensão/diagnóstico , Algoritmos , Calibragem , Desenho de Equipamento , Estudos de Avaliação como Assunto , Humanos
8.
J Hypertens ; 8(7): 635-40, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2168453

RESUMO

In 166 patients attending a hypertension review clinic, we compared supine and sitting blood pressure measurements and first and second measurements (1 min apart) in each position to determine whether any differences seen might have implications for the routine measurement of blood pressure in these patients, as a group or as individuals. Measurements were made with the Copal UA-251 semi-automated sphygmomanometer. In the group there was no significant difference between the first and the second diastolic measurements. The first systolic measurement was on average 3-4 mmHg higher than the second in both positions. Mean supine systolic pressures were 2-3 mmHg higher and diastolic pressures 2-3 mmHg lower than the corresponding sitting pressures. In individual subjects there were substantial disagreements between successive measurements in both positions and between positions. However, these differences would not have influenced blood pressure management in more than a few instances. We suggest that two measurements should routinely be taken, and the average recorded, particularly when the average exceeds 155/90 mmHg.


Assuntos
Determinação da Pressão Arterial/métodos , Hipertensão/diagnóstico , Postura , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Fatores de Tempo
9.
J Hypertens ; 6(8): 627-32, 1988 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3183368

RESUMO

A group of hypertensive patients (n = 2855) with an untreated diastolic blood pressure greater than or equal to 90 mmHg were followed in the Department of Health and Social Security (DHSS) Hypertension Care Computing Project (DHCCP) for periods of up to 10 years. During this period 191 of these patients died. Survival was assessed in relation to pretreatment blood pressure levels and blood pressure achieved during treatment. The blood pressure during treatment was a useful predictor of mortality, but the pretreatment pressure was not. After adjusting for age, mortality was particularly related to the height of the systolic and diastolic blood pressure during the second and third years of treatment. In men, age-standardized 5-year mortality was greater than 10% in those with a first year treated systolic pressure greater than 150 mmHg or a diastolic pressure greater than 95 mmHg. In women, age standardized 5-year mortality was greater than 5% with the same levels of treated blood pressure. The longest survival occurred with the lowest bands of treated pressure, i.e. systolic pressure less than 140 and diastolic pressure less than 90 mmHg; the 5-year mortality being less than 7% in men and less than 3% in women. Treated systolic and diastolic pressures were useful in predicting death from ischaemic heart disease (IHD).


Assuntos
Hipertensão/mortalidade , Pressão Sanguínea , Feminino , Humanos , Hipertensão/terapia , Masculino
10.
J Hypertens ; 4(1): 93-9, 1986 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3958486

RESUMO

A prospective study has been carried out to determine the causes of death and risk factors for survival in 4994 patients referred with a diagnosis of hypertension to hospital specialist clinics and 457 patients treated by their general practitioners for this condition. At the time of entering the prospective study, 69% of the patients were already being treated for hypertension. Four hundred and eleven patients have died, and their causes of death and death rates have been compared with the rates for the population of England and Wales. Ischaemic heart disease accounted for over one-third of the deaths and stroke for one-fifth. The death rates for these conditions were two to five times those expected for men and women aged 50-59 years and up to twice the rate expected for the age group 60-69 years. Survival in these selected patients was impaired by the following independent risk indicators: cigarette smoking, previous history of myocardial infarction or stroke, diagnosis of angina, impaired renal function and raised blood sugar. The following factors were not independent positive risk factors: smoking a pipe or cigars, obesity, a low plasma potassium and an elevated serum uric acid.


Assuntos
Hipertensão/mortalidade , Adolescente , Adulto , Idoso , Glicemia/análise , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/mortalidade , Doença das Coronárias/complicações , Doença das Coronárias/mortalidade , Inglaterra , Feminino , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Nefropatias/complicações , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Estudos Prospectivos , Risco , Fumar , Ureia/sangue , País de Gales
11.
J Hypertens ; 13(9): 957-64, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8586830

RESUMO

OBJECTIVE: To determine the benefits and risks of drinking alcohol in treated hypertensives. DESIGN: A prospective study of 6,369 hypertensives (3,161 men) attending primarily hospital clinics in the UK. METHODS: Relative risks both for drinkers compared with non-drinkers and for level of alcohol consumption were calculated for mortality from ischaemic heart disease, stroke, non-circulatory and all causes. RESULTS: At presentation 76% of the men and 48% of the women reported recent alcohol consumption. Compared with drinkers, non-drinkers were older, less likely to smoke and had a higher untreated blood pressure. After adjustment for confounding factors, male drinkers had a reduced risk of stroke mortality and possibly of ischaemic heart disease mortality. Similar results were observed in women for stroke mortality but not for ischaemic heart disease mortality. The trend remained after adjustment for previous cardiovascular disease. In men the lowest risk of ischaemic heart disease mortality occurred at intakes of > 21 units per week and stroke mortality was lowest at 1-10 units per week. Men consuming > 21 units per week had a twofold higher non-circulatory mortality. Total mortality was lowest in men who drank 1-10 units per week. Similar effects of alcohol on cardiovascular mortality were observed in women. CONCLUSIONS: Alcohol intake may reduce stroke mortality in treated hypertensives. Ischaemic heart disease mortality in men may also be reduced, especially at higher intakes ( > 21 units per week). The beneficial effects were offset by increasing incidence of non-circulatory causes of death. Alcohol consumption of 1-10 units per week was associated with the lowest mortality in men.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Transtornos Cerebrovasculares/mortalidade , Hipertensão/mortalidade , Isquemia Miocárdica/mortalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas/fisiopatologia , Pressão Sanguínea , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/fisiopatologia , Feminino , Seguimentos , Humanos , Hipertensão/complicações , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/complicações , Isquemia Miocárdica/fisiopatologia , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Fumar/efeitos adversos
12.
J Hypertens ; 10(10): 1273-8, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1335011

RESUMO

OBJECTIVE: To determine the relation between mortality from ischaemic heart disease (IHD) and treated blood pressure at different ages. DESIGN: Prospectively, 6216 patients were studied for a mean of 107 months. SETTING: Of the total patients, 95% were followed in five hospital-based hypertension clinics and the remainder in four group general practices. PATIENTS: Respectively, 2250 and 2126 hypertensive men and women aged < 60 years and 822 and 1018 aged > or = 60 years. MAIN OUTCOME MEASURES: Mortality (any mention on the death certificate) from IHD. RESULTS: Four hundred and sixty-seven patients died with IHD mentioned on the death certificate. The relation between both diastolic blood pressure (DBP) and systolic blood pressure (SBP) during the first 3-12 months of treatment and subsequent IHD mortality was examined. Under the age of 60 years the relative hazard rate (RHR) for death from IHD tended to increase with DBP in both men and women. Above the age of 60 years there was no important or significant relation between IHD mortality and treated DBP. For SBP there was no reduction in the positive relation between IHD mortality and blood pressure in the older age groups. The RHR for SBP ranged between 1.008 and 1.021 in men and women over and under the age of 60 years. CONCLUSIONS: The positive relation between DBP and IHD mortality decreased with increasing age and, in women aged > or = 60 years, even inverted, partly explaining the negative relation reported between DBP and total mortality in the very old.


Assuntos
Hipertensão/complicações , Isquemia Miocárdica/mortalidade , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea , Diástole , Feminino , Humanos , Hipertensão/terapia , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/etiologia , Estudos Prospectivos , Fatores de Risco
13.
Br J Pharmacol ; 77(4): 667-77, 1982 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7150874

RESUMO

1 The effect of chlorpromazine, metyrapone, imipramine and SKF 525-A on the hepatic first pass elimination of propranolol has been studied in the pithed rat. 2 The effect of chlorpromazine, metyrapone, imipramine and SKF 525-A on the inhibition caused by propranolol of an elicited electrically induced tachycardia has also been studied. 3 The hepatic first pass elimination of propranolol was reduced following pretreatment with chlorpromazine, imipramine and SKF 525-A but was not affected by pretreatment with metyrapone. 4 Chlorpromazine, imipramine and SKF 525-A all resulted in an increased propranolol blood concentration after hepatic portal vein administration which was associated with decreased formation of metabolites and an enhanced inhibition of an electrically induced tachycardia.


Assuntos
Clorpromazina/farmacologia , Imipramina/farmacologia , Fígado/metabolismo , Metirapona/farmacologia , Proadifeno/farmacologia , Propranolol/metabolismo , Animais , Biotransformação , Cinética , Fígado/efeitos dos fármacos , Masculino , Ratos , Ratos Endogâmicos , Medula Espinal/fisiologia
14.
Br J Pharmacol ; 101(2): 301-6, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2124159

RESUMO

1. The pharmacokinetics of gamma-glutamyl-L-dopa (gludopa) and its metabolite, L-dopa, have been studied in normal rats at three dose levels of gludopa: 2 mg kg-1, 5 mg kg-1 and 7.5 mg kg-1. The extent of metabolism in normal rats, and the pharmacokinetics in anephric rats and rats with glycerol-induced acute renal failure (ARF) were also studied at a gludopa dose of 2 mg kg-1. 2. Gludopa was extensively metabolised to L-dopa with only about 10% of an injected dose being excreted unchanged. Normal rats had a rapid gludopa clearance of 50.9 +/- 9.6 ml min-1 kg-1 and elimination rate constant of 2.99 +/- 0.27 h-1. The mean residence time and half-life were 20.9 +/- 1.4 and 14.4 +/- 1.0 min, respectively. The apparent volume of distribution at steady state was 1.05 +/- 0.18 l kg-1. 3. No statistically significant differences were found in the main pharmacokinetic parameters between ARF and controls for either gludopa or its metabolite L-dopa. 4. In anephric rats and controls the kidneys were found to contribute about 68.5% and 67.2% to the elimination of gludopa and the metabolite L-dopa, respectively. 5. These results confirm that gludopa is an efficient pro-drug for L-dopa, and that the kidneys are the major site of gludopa metabolism. It seems likely that the renal specificity of gludopa persists in ARF.


Assuntos
Injúria Renal Aguda/metabolismo , Di-Hidroxifenilalanina/análogos & derivados , Nefropatias/metabolismo , Injúria Renal Aguda/induzido quimicamente , Animais , Di-Hidroxifenilalanina/farmacocinética , Glicerol , Masculino , Nefrectomia , Ratos , Ratos Endogâmicos
15.
Biochem Pharmacol ; 36(14): 2311-6, 1987 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-3111481

RESUMO

The stabilities of several drug oxidation and conjugation pathways in human adult hepatocytes have been investigated during 72 hr culture. Cytochrome P-450-dependent mixed function oxidase was measured by the O-dealkylations of ethoxyresorufin (EROD), pentoxyresorufin (PROD) and benzyloxyresorufin (BROD), which are probes for different isozymes of cytochrome P-450 in the rat. EROD declined to 64% of initial fresh cell values after 72 hr in culture, whereas PROD increased to 162% and BROD remained relatively constant. Addition of phenobarbitone to the culture medium selectively increased PROD to a greater extent than EROD and did not affect BROD. NADPH-cytochrome c reductase and NADH-cytochrome b5 reductase were markedly labile during culture, declining to 32% and 22% of fresh cell values respectively. Epoxide hydrolase (EH) showed a large transient increase (2-5-fold) in enzyme activity 24 hr after culture, declining to fresh cell values by 48 hr. UDP-glucuronyltransferase (GT) activity towards phenolphthalein and 1-naphthol also increased (2-3-fold) during the 72 hr of culture, the greater and more rapid increase being observed with phenolphthalein glucuronidation. Sulphotransferase activity declined rapidly within 24 hr of culture, whereas reduced glutathione (GSH) levels and GSH conjugation were maintained at fresh cell values for 72 hr.


Assuntos
Biotransformação , Fígado/citologia , Oxigenases de Função Mista/metabolismo , Adulto , Biotransformação/efeitos dos fármacos , Células Cultivadas , Sistema Enzimático do Citocromo P-450/metabolismo , Feminino , Glucuronosiltransferase/metabolismo , Glutationa Transferase/metabolismo , Humanos , Inativação Metabólica/efeitos dos fármacos , Isoenzimas/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Fenobarbital/farmacologia
16.
J Hum Hypertens ; 1(2): 121-6, 1987 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3333523

RESUMO

Eighteen patients whose clinic blood pressure (BP) remained over 95 mmHg despite treatment with captopril 50 mg twice daily plus frusemide 40 mg twice daily were randomised in a crossover study to four weeks' treatment with once daily atenolol 100 mg, slow release propranolol 160 mg or placebo. The reduction in BP on atenolol was superior to that on both propranolol and placebo. The mean supine BP 24 hours post dosing were 177/110 mmHg (placebo), 173/109 mmHg (propranolol) and 164/100 mmHg (atenolol). The corresponding mean heart rates were 77 bpm (placebo), 63 bpm (propranolol) and 62 bpm (propranolol) and 62 bpm (atenolol). The difference in hypotensive efficacy between atenolol and propranolol is not readily explained but our study shows that atenolol has a clinically useful supplementary effect on BP. Refractory hypertension remains an important clinical problem and further studies are required to establish the optimum combination of drugs that should be used with captopril in order to achieve 'target' BP in patients with moderate to severe hypertension.


Assuntos
Atenolol/administração & dosagem , Captopril/administração & dosagem , Furosemida/administração & dosagem , Hipertensão/tratamento farmacológico , Propranolol/administração & dosagem , Idoso , Aldosterona/sangue , Pressão Sanguínea/efeitos dos fármacos , Ensaios Clínicos como Assunto , Creatinina/sangue , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição Aleatória , Renina/sangue
17.
J Hum Hypertens ; 10(11): 763-7, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9004107

RESUMO

This is a randomised, double-blind, placebo-controlled, four-way crossover study to determine if indomethacin attenuates the hypotensive effect of trandolapril. Twenty-three hypertensive patients (diastolic blood pressure (DBP) 95-115) requiring NSAID were recruited. Seventeen completed the study. Three week treatment periods: trandolapril 2 mg od and indomethacin 25 mg tds, trandolapril 2 mg and placebo, indomethacin and placebo, placebo and placebo. Clinic and ambulatory BP after 3 weeks of each treatment. Study had 85% power to detect a 5 mm Hg difference in BP (s.d. 7 mm Hg). End of treatment clinic BPs were: 152.9/98 mm Hg (95% CI 147.2, 158.6/95.8, 101.4) with placebo and placebo; 150.4/94.9 mm Hg (95% CI 144.7, 156.1/92.1, 97.7) with trandolapril and indomethacin; 148.2/96.5 mm Hg (95% CI 142.5, 153.9/93.7, 99.3) with trandolapril and placebo; and 156.6/97.4 mm Hg (95% CI 150.9, 162.3/94.6, 100.2) with indomethacin and placebo. There were no significant interactions between trandolapril and indomethacin for clinic systolic BP (SBP) (P = 0.79) or clinic DBP (P = 0.87). When trandolapril treatments (placebo or with indomethacin) were compared to treatments without trandolapril (placebo or indomethacin), trandolapril lowered clinic SBP by 5.4 mm Hg (P = 0.047) and DBP by 2.3 mm Hg (P = 0.08). Mean ambulatory BP was: 140.6/88.2 mm Hg (trandolapril and placebo); 142.8/89.7 mm Hg (trandolapril and indomethacin); 149.6/95.0 mm Hg, (indomethacin and placebo); 147.7/94.0 mm Hg (placebo and placebo). Compared with placebo, trandolapril and placebo lowered BP by 6.5/7.5 mm Hg (P < 0.001, SBP; P < 0.001, DBP). Compared with indomethacin, trandolapril and indomethacin lowered BP by 5.0/5.5 mm Hg (P = 0.001, SBP; P < 0.001, DBP). In the present study trandolapril 2 mg lowered clinic SBP and ambulatory BP, but indomethacin did not attenuate this. Indomethacin had no significant effect on either clinic or ambulatory BP. The antihypertensive effects of trandolapril in this study were modest. Patient selection factors may have contributed to the observed responses, but it seems unlikely from these data that a clinically important drug interaction has occurred.


Assuntos
Hipotensão/induzido quimicamente , Indóis/farmacologia , Indometacina/farmacologia , Adulto , Idoso , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Estudos Cross-Over , Método Duplo-Cego , Interações Medicamentosas , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
18.
J Hum Hypertens ; 12(6): 411-6, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9705044

RESUMO

The anti-hypertensive efficacy of once-daily amlodipine (up to 10 mg) and lisinopril (up to 20 mg) were compared in terms of clinic and ambulatory blood pressure (BP) control, in an observer-blind, two-period crossover study. Following a 4-week placebo run-in period, patients underwent two active treatment phases each lasting 12 weeks and separated by a 4-week washout period. Sixty patients with a supine diastolic BP between 90 and 120 mm Hg were included, irrespective of whether or not they had received previous anti-hypertensive medication. Amlodipine reduced supine systolic and diastolic clinic BP significantly more than lisinopril (-20+/-2/-14+/-1 vs -11 3/-7+/-1 mm Hg; P=0.02/ P=0.001) 24 h post-dose. Clinic standing diastolic BP was also significantly reduced with amlodipine compared with lisinopril (P=0.05). Both drugs produced control of mean ambulatory BP relative to baseline over 24 h. Amlodipine showed more consistent control of BP over the 24-h period in contrast to lisinopril which exerted its greatest effect during the daytime.


Assuntos
Anlodipino/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Lisinopril/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Monitorização Ambulatorial da Pressão Arterial , Ritmo Circadiano , Estudos Cross-Over , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Método Simples-Cego , Resultado do Tratamento
19.
J Hum Hypertens ; 11(4): 205-11, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9185024

RESUMO

OBJECTIVE: A case control study has reported a 60% higher risk of myocardial infarction in hypertensives treated with a calcium channel blocker (CCB). We examined the Department of Health Hypertension Care Computing Project (DHCCP) data to see if we could confirm or refute this suggestion. DESIGN: Two case control studies, matched and unmatched, plus two longitudinal studies from 1 year of presentation, one for all subjects given a CCB for more than 1 year compared with those not given this drug, and the second comparing survival on the different drugs initially given between 3 and 12 months of follow-up. SUBJECTS: A total of 9328 subjects were included in the analyses and 2154 died. Of these, 6406 received one or more of the following index drugs: 26% a calcium channel blocker (CCB); 84% a diuretic; 29% alpha methyldopa; 12% a beta-blocker (BB); and 11% an angiotensin-converting enzyme (ACE) inhibitor. The CCBs were nifedipine, diltiazem or verapamil. RESULTS: In the case control studies a group given diuretics +/- other treatments (but not including one of the index drugs) provided a reference group with a relative risk (RR) of 1.0. In the matched case control study the adjusted RR for a CCB without a diuretic was 1.32 (95% CI 0.64-2.70) for IHD mortality and 1.05 (95% CI 0.60-1.84) for cardiovascular mortality. Similar results were observed for methyldopa, BBs and ACE inhibitors. The results in the unmatched case control analysis were also similar. The longitudinal study comparing all those treated for over 1 year with a CCB with all other treatments showed a RR for total mortality of 1.03 (95% CI 0.85-1.25). The longitudinal study of total mortality according to treatment initiated at 3-12 months found results of a similar magnitude for CCBs, methyldopa and BBs. CONCLUSIONS: The reference diuretic group had less severe cardiovascular disease than other groups. Treatment with a CCB, BB or methyldopa was associated with an excess mortality in comparison with this reference group. The excess was similar in the different drug groups.


Assuntos
Bloqueadores dos Canais de Cálcio/efeitos adversos , Hipertensão/tratamento farmacológico , Isquemia Miocárdica/induzido quimicamente , Isquemia Miocárdica/mortalidade , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Bloqueadores dos Canais de Cálcio/uso terapêutico , Estudos de Casos e Controles , Feminino , Humanos , Hipertensão/mortalidade , Incidência , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Distribuição por Sexo , Taxa de Sobrevida , Reino Unido/epidemiologia
20.
J Hum Hypertens ; 2(4): 219-27, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2907053

RESUMO

The DHCCP is a multicentre observational study of patients being treated for hypertension in the United Kingdom. The influence of the type of anti-hypertensive therapy on survival was examined in 2,697 patients followed from 1971 with 206 deaths up to November 1981. Patients were classified by three types of treatment after one year in the project: betablockers (1,387), methyldopa (452) and others (667), (70% on diuretics only). The data were analysed both for all patients and for a subset excluding patients with previous ischaemic heart disease by all cause and IHD age-adjusted rates and life table analysis. Men on beta blockers had lower rates for total mortality, when compared with men on methyldopa (64% of the methyldopa rate, P less than 0.05) and when compared with men on other treatments (76% of the other treatment rate, P less than 0.1). The results for IHD mortality were similar. This improved survival of men in the beta blocker group was also found in the subset with no prior history of IHD. The benefit of beta blockers was not apparent in women: the lowest rates were observed for women on methyldopa, but the confidence limits for the ratios of relative rates were wide. Adjustment for blood pressure and cigarette smoking using the Cox proportional hazards model did not substantially modify the ratios of the mortality rates for the treatment groups. A sub-group analysis showed the reduction in all cause and IHD mortality associated with beta blockers was mainly due to the effect in non-smoking men.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Hipertensão/tratamento farmacológico , Feminino , Humanos , Hipertensão/mortalidade , Masculino , Pessoa de Meia-Idade , Fatores Sexuais
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